Lateral pararectal versus transrectal stoma placement for prevention of parastomal herniation

BACKGROUND

A parastomal hernia is defined as an incisional hernia related to a stoma, and belongs to the most common stoma-related complications. Many factors, which are considered to influence the incidence of parastomal herniation, have been investigated. However, it remains unclear whether the enterostomy should be placed through, or lateral to the rectus abdominis muscle, in order to prevent parastomal herniation and other important stoma complications.

OBJECTIVES

To assess if there is a difference regarding the incidence of parastomal herniation and other stoma complications, such as ileus and stenosis, in lateral pararectal versus transrectal stoma placement in people undergoing elective or emergency abdominal wall enterostomy.

SEARCH METHODS

For this update, we searched for all types of published and unpublished randomized and non-randomized studies in four medical databases: CENTRAL, PubMed, LILACS, Science Ciation Index, and two trials registers: ICTRP Search Portal and ClinicalTrials.gov to 9 November 2018. We applied no language restrictions.

SELECTION CRITERIA

Randomized and non-randomized studies comparing lateral pararectal versus transrectal stoma placement with regard to parastomal herniation and other stoma-related complications.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We conducted data analyses according to the recommendations of Cochrane and the Cochrane Colorectal Cancer Group (CCCG). We rated quality of evidence according to the GRADE approach.

MAIN RESULTS

Randomized controlled trials (RCT)Only one RCT met the inclusion criteria. The participants underwent enterostomy placement in the frame of an operation for: rectal cancer (37/60), ulcerative colitis (14/60), familial adenomatous polyposis (7/60), and other (2/60).The results between the lateral pararectal and the transrectal approach groups were inconclusive for the incidence of parastomal herniation (risk ratio (RR) 1.34, 95% confidence interval (CI) 0.40 to 4.48; low-quality evidence); development of ileus or stenosis (RR 2.0, 95% CI 0.19 to 20.9; low-quality evidence); or skin irritation (RR 0.67, 95% CI 0.21 to 2.13; moderate-quality evidence). The results were also inconclusive for the subgroup analysis in which we compared the effect of ileostomy versus colostomy on parastomal herniation. The study did not measured other stoma-related morbidities, or stoma-related mortality, but did measure quality of life, which was not one of our outcomes of interest.Non-randomized studies (NRS)Ten retrospective cohort studies, with a total of 864 participants, met the inclusion criteria. The indications for enterostomy placement and the baseline characteristics of the participants (age, co-morbidities, disease-severity) varied between studies. All included studies reported results for the primary outcome (parastomal herniation) and one study also reported data on one of the secondary outcomes (stomal prolapse).The effects of different surgical approaches on parastomal herniation (RR 1.22, 95% CI 0.84 to 1.75; 10 studies, 864 participants; very low-quality evidence) and the occurrence of stomal prolapse (RR 1.23, 95% CI 0.39 to 3.85; 1 study, 145 participants; very low-quality evidence) are uncertain.None of the included studies measured other stoma-related morbidity or stoma-related mortality.

AUTHORS' CONCLUSIONS

The present systematic review of randomized and non-randomized studies found inconsistent results between the two compared interventions regarding their potential to prevent parastomal herniation.In conclusion, there is still a lack of high-quality evidence to support the ideal surgical technique of stoma formation. The available moderate-, low-, and very low-quality evidence, does not support or refute the superiority of one of the studied stoma formation techniques over the other.

Laparoscopic versus open surgery for suspected appendicitis

BACKGROUND

The removal of the acute appendix is one of the most frequently performed surgical procedures. Open surgery associated with therapeutic efficacy has been the treatment of choice for acute appendicitis. However, in consequence of the evolution of endoscopic surgery, the operation can also be performed with minimally invasive surgery. Due to smaller incisions, the laparoscopic approach may be associated with reduced postoperative pain, reduced wound infection rate, and shorter time until return to normal activity.This is an update of the review published in 2010.

OBJECTIVES

To compare the effects of laparoscopic appendectomy (LA) and open appendectomy (OA) with regard to benefits and harms.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE and Embase (9 February 2018). We identified proposed and ongoing studies from World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov and EU Clinical Trials Register (9 February 2018). We handsearched reference lists of identified studies and the congress proceedings of endoscopic surgical societies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing LA versus OA in adults or children.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted data. We performed the meta-analyses using Review Manager 5. We calculated the Peto odds ratio (OR) for very rare outcomes, and the mean difference (MD) for continuous outcomes (or standardised mean differences (SMD) if researchers used different scales such as quality of life) with 95% confidence intervals (CI). We used GRADE to rate the quality of the evidence.

MAIN RESULTS

We identified 85 studies involving 9765 participants. Seventy-five trials included 8520 adults and 10 trials included 1245 children. Most studies had risk of bias issues, with attrition bias being the largest source across studies due to incomplete outcome data.In adults, pain intensity on day one was reduced by 0.75 cm on a 10 cm VAS after LA (MD -0.75, 95% CI -1.04 to -0.45; 20 RCTs; 2421 participants; low-quality evidence). Wound infections were less likely after LA (Peto OR 0.42, 95% CI 0.35 to 0.51; 63 RCTs; 7612 participants; moderate-quality evidence), but the incidence of intra-abdominal abscesses was increased following LA (Peto OR 1.65, 95% CI 1.12 to 2.43; 53 RCTs; 6677 participants; moderate-quality evidence).The length of hospital stay was shortened by one day after LA (MD -0.96, 95% CI -1.23 to -0.70; 46 RCTs; 5127 participant; low-quality evidence). The time until return to normal activity occurred five days earlier after LA than after OA (MD -4.97, 95% CI -6.77 to -3.16; 17 RCTs; 1653 participants; low-quality evidence). Two studies showed better quality of life scores following LA, but used different scales, and therefore no pooled estimates were presented. One used the SF-36 questionnaire two weeks after surgery and the other used the Gastro-intestinal Quality of Life Index six weeks and six months after surgery (both low-quality evidence).In children, we found no differences in pain intensity on day one (MD -0.80, 95% CI -1.65 to 0.05; 1 RCT; 61 participants; low-quality evidence), intra-abdominal abscesses after LA (Peto OR 0.54, 95% CI 0.24 to 1.22; 9 RCTs; 1185 participants; low-quality evidence) or time until return to normal activity (MD -0.50, 95% CI -1.30 to 0.30; 1 RCT; 383 participants; moderate-quality evidence). However, wound infections were less likely after LA (Peto OR 0.25, 95% CI 0.15 to 0.42; 10 RCTs; 1245 participants; moderate-quality evidence) and the length of hospital stay was shortened by 0.8 days after LA (MD -0.81, 95% CI -1.01 to -0.62; 6 RCTs; 316 participants; low-quality evidence). Quality of life was not reported in any of the included studies.

AUTHORS' CONCLUSIONS

Except for a higher rate of intra-abdominal abscesses after LA in adults, LA showed advantages over OA in pain intensity on day one, wound infections, length of hospital stay and time until return to normal activity in adults. In contrast, LA showed advantages over OA in wound infections and length of hospital stay in children. Two studies reported better quality of life scores in adults. No study reported this outcome in children. However, the quality of evidence ranged from very low to moderate and some of the clinical effects of LA were small and of limited clinical relevance. Future studies with low risk of bias should investigate, in particular, the quality of life in children.

Survival differences with immediate versus delayed chemotherapy for asymptomatic incurable metastatic colorectal cancer

BACKGROUND

For patients with asymptomatic, incurable, metastatic colorectal cancer, palliative, systemic treatment can be started immediately, or can be delayed until disease-related symptoms occur. How the potential survival benefit of starting palliative, systemic treatment immediately after diagnosis weighs up against the potential side effects is currently under debate, and was investigated in this review.

OBJECTIVES

To assess the effects of immediate versus delayed chemotherapy, with or without targeted therapy, on overall survival, toxicity, quality of life, progression-free survival, and compliance with chemotherapy for individuals with asymptomatic, metastatic, incurable colorectal cancer.

SEARCH METHODS

We searched CENTRAL; 2018, Issue 8, MEDLINE Ovid, Embase Ovid, PsycINFO, the World Health Organization International Clinical Trials Registry Platform, and Clinicaltrials.gov, from inception to 23 August 2018. We did not apply limitations based on language or date of publication. We searched the reference lists of all included studies to identify trials that may not have been identified from the electronic searches.

SELECTION CRITERIA

Randomised controlled trials evaluating immediate versus delayed chemotherapy in persons with asymptomatic, metastatic, incurable colorectal cancer.

DATA COLLECTION AND ANALYSIS

We applied standard methodological procedures, according to the recommendations of Cochrane and Cochrane Colorectal Cancer. Two review authors independently reviewed the studies identified by literature searches, selected relevant trials, extracted data, and assessed risk of bias of the included studies. We used the Cochrane tool to assess risk of bias, Review Manager 5 software for meta-analysis, GRADE methods to evaluate the quality of the evidence, and GRADEpro GDT software to develop a 'Summary of findings' table.

MAIN RESULTS

We included three randomised controlled trials (351 participants) investigating immediate versus delayed chemotherapy in people diagnosed with asymptomatic, metastatic, incurable colorectal cancer. Giving immediate versus delayed chemotherapy may make little or no difference to overall survival (hazard ratio (HR) 1.17, 95% confidence interval (CI) 0.93 to 1.46; 3 studies, 351 persons; low-quality evidence). For toxicity, giving immediate versus delayed chemotherapy may make little or no difference to the risk of grade 3 or 4 nausea and vomiting (risk ratio (RR) 0.84, 95% CI 0.31 to 2.25; 2 studies, 140 persons; very low-quality evidence), stomatitis (RR 1.10, 95% CI 0.47 to 2.55; 2 studies, 140 persons; very low-quality evidence), or diarrhoea (RR 0.69, 95% CI 0.34 to 1.40; 2 studies, 140 persons, very low-quality evidence). We are uncertain whether delayed chemotherapy made a difference to quality of life (very low-quality evidence), progression-free survival (low-quality evidence), or compliance with chemotherapy (low-quality evidence), as we had insufficient data to pool for these outcomes.

AUTHORS' CONCLUSIONS

Based on a limited number of trials, very sparse data, and uncertainty of the evidence, this review was unable to establish whether there was a difference in overall survival or other clinically relevant outcomes, between immediate or delayed chemotherapy in persons with metastatic, incurable, colorectal cancer. The results should be interpreted with caution.

Preoperative radiotherapy and curative surgery for the management of localised rectal carcinoma

BACKGROUND

This is an update of the original review published in 2007.Carcinoma of the rectum is a common malignancy, especially in high income countries. Local recurrence may occur after surgery alone. Preoperative radiotherapy (PRT) has the potential to reduce the risk of local recurrence and improve outcomes in rectal cancer.

OBJECTIVES

To determine the effect of preoperative radiotherapy for people with localised resectable rectal cancer compared to surgery alone.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; Issue 5, 2018) (4 June 2018), MEDLINE (Ovid) (1950 to 4 June 2018), and Embase (Ovid) (1974 to 4 June 2018). We also searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) for relevant ongoing trials (4 June 2018).

SELECTION CRITERIA

We included randomised controlled trials comparing PRT and surgery with surgery alone for people with localised advanced rectal cancer planned for radical surgery. We excluded trials that did not use contemporary radiotherapy techniques (with more than two fields to the pelvis).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the 'Risk of bias' domains for each included trial, and extracted data. For time-to-event data, we calculated the Peto odds ratio (Peto OR) and variances, and for dichotomous data we calculated risk ratios (RR) using the random-effects method. Potential sources of heterogeneity hypothesised a priori included study quality, staging, and the use of total mesorectal excision (TME) surgery.

MAIN RESULTS

We included four trials with a total of 4663 participants. All four trials reported short PRT courses, with three trials using 25 Gy in five fractions, and one trial using 20 Gy in four fractions. Only one study specifically required TME surgery for inclusion, whereas in another study 90% of participants received TME surgery.Preoperative radiotherapy probably reduces overall mortality at 4 to 12 years' follow-up (4 trials, 4663 participants; Peto OR 0.90, 95% CI 0.83 to 0.98; moderate-quality evidence). For every 1000 people who undergo surgery alone, 454 would die compared with 45 fewer (the true effect may lie between 77 fewer to 9 fewer) in the PRT group. There was some evidence from subgroup analyses that in trials using TME no or little effect of PRT on survival (P = 0.03 for the difference between subgroups).Preoperative radiotherapy may have little or no effect in reducing cause-specific mortality for rectal cancer (2 trials, 2145 participants; Peto OR 0.89, 95% CI 0.77 to 1.03; low-quality evidence).We found moderate-quality evidence that PRT reduces local recurrence (4 trials, 4663 participants; Peto OR 0.48, 95% CI 0.40 to 0.57). In absolute terms, 161 out of 1000 patients receiving surgery alone would experience local recurrence compared with 83 fewer with PRT. The results were consistent in TME and non-TME studies.There may be little or no difference in curative resection (4 trials, 4673 participants; RR 1.00, 95% CI 0.97 to 1.02; low-quality evidence) or in the need for sphincter-sparing surgery (3 trials, 4379 participants; RR 0.99, 95% CI 0.94 to 1.04; I² = 0%; low-quality evidence) between PRT and surgery alone.Low-quality evidence suggests that PRT may increase the risk of sepsis from 13% to 16% (2 trials, 2698 participants; RR 1.25, 95% CI 1.04 to 1.52) and surgical complications from 25% to 30% (2 trials, 2698 participants; RR 1.20, 95% CI 1.01 to 1.42) compared to surgery alone.Two trials evaluated quality of life using different scales. Both studies concluded that sexual dysfunction occurred more in the PRT group. Mixed results were found for faecal incontinence, and irradiated participants tended to resume work later than non-irradiated participants between 6 and 12 months, but this effect had attenuated after 18 months (low-quality evidence).

AUTHORS' CONCLUSIONS

We found moderate-quality evidence that PRT reduces overall mortality. Subgroup analysis did not confirm this effect in people undergoing TME surgery. We found consistent evidence that PRT reduces local recurrence. Risk of sepsis and postsurgical complications may be higher with PRT.The main limitation of the findings of the present review concerns their applicability. The included trials only assessed short-course radiotherapy and did not use chemotherapy, which is widely used in the contemporary management of rectal cancer disease. The differences between the trials regarding the criteria used to define rectal cancer, staging, radiotherapy delivered, the time between radiotherapy and surgery, and the use of adjuvant or postoperative therapy did not appear to influence the size of effect across the studies.Future trials should focus on identifying participants that are most likely to benefit from PRT especially in terms of improving local control, sphincter preservation, and overall survival while reducing acute and late toxicities (especially rectal and sexual function), as well as determining the effect of radiotherapy when chemotherapy is used and the optimal timing of surgery following radiotherapy.

Mesh versus non-mesh for inguinal and femoral hernia repair

BACKGROUND

This is an update of a Cochrane Review first published in 2001.Hernias are protrusions of all or part of an organ through the body wall that normally contains it. Groin hernias include inguinal (96%) and femoral (4%) hernias, and are often symptomatic with discomfort. They are extremely common, with an estimated lifetime risk in men of 27%. Occasionally they may present as emergencies with complications such as bowel incarceration, obstruction and strangulation. The definitive treatment of all hernias is surgical repair, inguinal hernia repair being one of the most common surgical procedures performed. Mesh (hernioplasty) and the traditional non-mesh repairs (herniorrhaphy) are commonly used, with an increasing preference towards mesh repairs in high-income countries.

OBJECTIVES

To evaluate the benefits and harms of different inguinal and femoral hernia repair techniques in adults, specifically comparing closure with mesh versus without mesh. Outcomes include hernia recurrence, complications (including neurovascular or visceral injury, haematoma, seroma, testicular injury, infection, postoperative pain), mortality, duration of operation, postoperative hospital stay and time to return to activities of daily living.

SEARCH METHODS

We searched the following databases on 9 May 2018: Cochrane Colorectal Cancer Group Specialized Register, Cochrane Central Register of Controlled Trials (Issue 1), Ovid MEDLINE (from 1950), Ovid Embase (from 1974) and Web of Science (from 1900). Furthermore, we checked the WHO International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for trials. We applied no language or publication restrictions. We also searched the reference lists of included trials and review articles.

SELECTION CRITERIA

We included randomised controlled trials of mesh compared to non-mesh inguinal or femoral hernia repairs in adults over the age of 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Where available, we collected information on adverse effects. We presented dichotomous data as risk ratios, and where possible we calculated the number needed to treat for an additional beneficial outcome (NNTB). We presented continuous data as mean difference. Analysis of missing data was based on intention-to-treat principles, and we assessed heterogeneity using an evaluation of clinical and methodological diversity, Chi² test and I² statistic. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included 25 studies (6293 participants) in this review. All included studies specified inguinal hernias, and two studies reported that femoral hernias were included.Mesh repair probably reduces the risk of hernia recurrence compared to non-mesh repair (21 studies, 5575 participants; RR 0.46, 95% CI 0.26 to 0.80, I² = 44%, moderate-quality evidence). In absolute numbers, one hernia recurrence was prevented for every 46 mesh repairs compared with non-mesh repairs. Twenty-four studies (6293 participants) assessed a wide range of complications with varying follow-up times. Neurovascular and visceral injuries were more common in non-mesh repair groups (RR 0.61, 95% CI 0.49 to 0.76, I² = 0%, NNTB = 22, high-quality evidence). Wound infection was found slightly more commonly in the mesh group (20 studies, 4540 participants; RR 1.29, 95% CI 0.89 to 1.86, I² = 0%, NNTB = 200, low-quality evidence). Mesh repair reduced the risk of haematoma compared to non-mesh repair (15 studies, 3773 participants; RR 0.88, 95% CI 0.68 to 1.13, I² = 0%, NNTB = 143, low-quality evidence). Seromas probably occur more frequently with mesh repair than with non-mesh repair (14 studies, 2640 participants; RR 1.63, 95% CI 1.03 to 2.59, I² = 0%, NNTB = 72, moderate-quality evidence), as does wound swelling (two studies, 388 participants; RR 4.56, 95% CI 1.02 to 20.48, I² = 33%, NNTB = 72, moderate-quality evidence). The comparative effect on wound dehiscence is uncertain due to wide confidence intervals (two studies, 329 participants; RR 0.55, 95% CI 0.12 to 2.48, I² = 37% NNTB = 77, low-quality evidence). Testicular complications showed nearly equivocal results; they probably occurred slightly more often in the mesh group however the confidence interval around the effect was wide (14 studies, 3741 participants; RR 1.06, 95% CI 0.63 to 1.76, I² = 0%, NNTB = 2000, low-quality evidence). Mesh reduced the risk of postoperative urinary retention compared to non-mesh (eight studies, 1539 participants; RR 0.53, 95% CI 0.38 to 0.73, I² = 56%, NNTB = 16, moderate-quality evidence).Postoperative and chronic pain could not be compared due to variations in measurement methods and follow-up time (low-quality evidence).No deaths occurred during the follow-up periods reported in the seven studies (2546 participants) reporting this outcome (high-quality evidence).The average operating time was longer for non-mesh repairs by a mean of 4 minutes 22 seconds, despite wide variation across the studies regarding size and direction of effect, thus this result is uncertain (20 studies, 4148 participants; 95% CI -6.85 to -1.60, I²= 97%, very low-quality evidence). Hospital stay may be shorter with mesh repair, by 0.6 days (12 studies, 2966 participants; 95% CI -0.86 to -0.34, I² = 98%, low-quality evidence), and participants undergoing mesh repairs may return to normal activities of daily living a mean of 2.87 days sooner than those with non-mesh repair (10 studies, 3183 participants; 95% CI -4.42 to -1.32, I² = 96%, low-quality evidence), although the results of both these outcomes are also limited by wide variation in the size and direction of effect across the studies.

AUTHORS' CONCLUSIONS

Mesh and non-mesh repairs are effective surgical approaches in treating hernias, each demonstrating benefits in different areas. Compared to non-mesh repairs, mesh repairs probably reduce the rate of hernia recurrence, and reduce visceral or neurovascular injuries, making mesh repair a common repair approach. Mesh repairs may result in a reduced length of hospital stay and time to return to activities of daily living, but these results are uncertain due to variation in the results of the studies. Non-mesh repair is less likely to cause seroma formation and has been favoured in low-income countries due to low cost and reduced availability of mesh materials. Risk of bias in the included studies was low to moderate and generally handled well by study authors, with attention to details of allocation, blinding, attrition and reporting.

Virtual reality simulation training for health professions trainees in gastrointestinal endoscopy

BACKGROUND

Endoscopy has traditionally been taught with novices practicing on real patients under the supervision of experienced endoscopists. Recently, the growing awareness of the need for patient safety has brought simulation training to the forefront. Simulation training can provide trainees with the chance to practice their skills in a learner-centred, risk-free environment. It is important to ensure that skills gained through simulation positively transfer to the clinical environment. This updated review was performed to evaluate the effectiveness of virtual reality (VR) simulation training in gastrointestinal endoscopy.

OBJECTIVES

To determine whether virtual reality simulation training can supplement and/or replace early conventional endoscopy training (apprenticeship model) in diagnostic oesophagogastroduodenoscopy, colonoscopy, and/or sigmoidoscopy for health professions trainees with limited or no prior endoscopic experience.

SEARCH METHODS

We searched the following health professions, educational, and computer databases until 12 July 2017: the Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Ovid Embase, Scopus, Web of Science, BIOSIS Previews, CINAHL, AMED, ERIC, Education Full Text, CBCA Education, ACM Digital Library, IEEE Xplore, Abstracts in New Technology and Engineering, Computer and Information Systems Abstracts, and ProQuest Dissertations and Theses Global. We also searched the grey literature until November 2017.

SELECTION CRITERIA

We included randomised and quasi-randomised clinical trials comparing VR endoscopy simulation training versus any other method of endoscopy training with outcomes measured on humans in the clinical setting, including conventional patient-based training, training using another form of endoscopy simulation, or no training. We also included trials comparing two different methods of VR training.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and methodological quality of trials, and extracted data on the trial characteristics and outcomes. We pooled data for meta-analysis where participant groups were similar, studies assessed the same intervention and comparator, and had similar definitions of outcome measures. We calculated risk ratio for dichotomous outcomes with 95% confidence intervals (CI). We calculated mean difference (MD) and standardised mean difference (SMD) with 95% CI for continuous outcomes when studies reported the same or different outcome measures, respectively. We used GRADE to rate the quality of the evidence.

MAIN RESULTS

We included 18 trials (421 participants; 3817 endoscopic procedures). We judged three trials as at low risk of bias. Ten trials compared VR training with no training, five trials with conventional endoscopy training, one trial with another form of endoscopy simulation training, and two trials compared two different methods of VR training. Due to substantial clinical and methodological heterogeneity across our four comparisons, we did not perform a meta-analysis for several outcomes. We rated the quality of evidence as moderate, low, or very low due to risk of bias, imprecision, and heterogeneity.Virtual reality endoscopy simulation training versus no training: There was insufficient evidence to determine the effect on composite score of competency (MD 3.10, 95% CI -0.16 to 6.36; 1 trial, 24 procedures; low-quality evidence). Composite score of competency was based on 5-point Likert scales assessing seven domains: atraumatic technique, colonoscope advancement, use of instrument controls, flow of procedure, use of assistants, knowledge of specific procedure, and overall performance. Scoring range was from 7 to 35, a higher score representing a higher level of competence. Virtual reality training compared to no training likely provides participants with some benefit, as measured by independent procedure completion (RR 1.62, 95% CI 1.15 to 2.26; 6 trials, 815 procedures; moderate-quality evidence). We evaluated overall rating of performance (MD 0.45, 95% CI 0.15 to 0.75; 1 trial, 18 procedures), visualisation of mucosa (MD 0.60, 95% CI 0.20 to 1.00; 1 trial, 55 procedures), performance time (MD -0.20 minutes, 95% CI -0.71 to 0.30; 2 trials, 29 procedures), and patient discomfort (SMD -0.16, 95% CI -0.68 to 0.35; 2 trials, 145 procedures), all with very low-quality evidence. No trials reported procedure-related complications or critical flaws (e.g. bleeding, luminal perforation) (3 trials, 550 procedures; moderate-quality evidence).Virtual reality endoscopy simulation training versus conventional patient-based training: One trial reported composite score of competency but did not provide sufficient data for quantitative analysis. Virtual reality training compared to conventional patient-based training resulted in fewer independent procedure completions (RR 0.45, 95% CI 0.27 to 0.74; 2 trials, 174 procedures; low-quality evidence). We evaluated performance time (SMD 0.12, 95% CI -0.55 to 0.80; 2 trials, 34 procedures), overall rating of performance (MD -0.90, 95% CI -4.40 to 2.60; 1 trial, 16 procedures), and visualisation of mucosa (MD 0.0, 95% CI -6.02 to 6.02; 1 trial, 18 procedures), all with very low-quality evidence. Virtual reality training in combination with conventional training appears to be advantageous over VR training alone. No trials reported any procedure-related complications or critical flaws (3 trials, 72 procedures; very low-quality evidence).Virtual reality endoscopy simulation training versus another form of endoscopy simulation: Based on one study, there were no differences between groups with respect to composite score of competency, performance time, and visualisation of mucosa. Virtual reality training in combination with another form of endoscopy simulation training did not appear to confer any benefit compared to VR training alone.Two methods of virtual reality training: Based on one study, a structured VR simulation-based training curriculum compared to self regulated learning on a VR simulator appears to provide benefit with respect to a composite score evaluating competency. Based on another study, a progressive-learning curriculum that sequentially increases task difficulty provides benefit with respect to a composite score of competency over the structured VR training curriculum.

AUTHORS' CONCLUSIONS

VR simulation-based training can be used to supplement early conventional endoscopy training for health professions trainees with limited or no prior endoscopic experience. However, we found insufficient evidence to advise for or against the use of VR simulation-based training as a replacement for early conventional endoscopy training. The quality of the current evidence was low due to inadequate randomisation, allocation concealment, and/or blinding of outcome assessment in several trials. Further trials are needed that are at low risk of bias, utilise outcome measures with strong evidence of validity and reliability, and examine the optimal nature and duration of training.

Prosthetic mesh placement for the prevention of parastomal herniation

BACKGROUND

Parastomal herniation is a common problem following formation of a stoma after both elective and emergency abdominal surgery. Symptomatic hernias give rise to a significant amount of patient morbidity, and in some cases mortality, and therefore may necessitate surgical treatment to repair the hernial defect and/or re-site the stoma. In an effort to reduce this complication, recent research has focused on the application of a synthetic or biological mesh, inserted during stoma formation to help strengthen the abdominal wall.

OBJECTIVES

The primary objective was to evaluate whether mesh reinforcement during stoma formation reduces the incidence of parastomal herniation. Secondary objectives included the safety or potential harms or both of mesh placement in terms of stoma-related infections, mesh-related infections, patient-reported symptoms/postoperative quality of life, and re-hospitalisation/ambulatory visits.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2018, Issue 1), Ovid MEDLINE (1970 to 11 January 2018), Ovid Embase (1974 to 11 January 2018), and Science Citation Index Expanded (1970 to 11 January 2018). To identify ongoing studies, we also searched the metaRegister of Controlled Trials (mRCT) on 11 January 2018.

SELECTION CRITERIA

We considered for inclusion all randomised controlled trials (RCTs) of prosthetic mesh (including biological/composite mesh) placement versus a control group (no mesh) for the prevention of parastomal hernia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies identified by the literature search for potential eligibility. We obtained the full articles for all studies that potentially met the inclusion criteria and included all those that met the criteria. Any differences in opinion between review authors were resolved by consensus. We pooled study data into a meta-analysis. We assessed heterogeneity by calculation of I² and expressed results for each variable as a risk ratio (RR) with corresponding 95% confidence intervals (CI). We expressed continous outcomes as mean difference (MD) with corresponding 95% CIs.

MAIN RESULTS

We included 10 RCTs involving a total of 844 participants. The primary outcome was overall incidence of parastomal herniation. Secondary outcomes were rate of reoperation at 12 months, operative time, postoperative length of hospital stay, stoma-related infections, mesh-related infections, quality of life, and rehospitalisation rate. We judged the risk of bias across all domains to be low in six trials. We judged four trials to have an overall high risk of bias.The overall incidence of parastomal hernia was less in participants receiving a prophylactic mesh compared to those who had a standard ostomy formation (RR 0.53, 95% CI 0.43 to 0.66; 10 studies, 771 participants; I² = 69%; low-quality evidence). In absolute numbers, the incidence of parastomal hernia was 22 per 100 participants (18 to 27) receiving prophylactic mesh compared to 41 per 100 participants having a standard ostomy formation.There were no differences in the need for reoperation (RR 0.90, 95% CI 0.50 to 1.64; 9 studies, 757 participants; I² = 0%; low-quality evidence); operative time (MD -6.50 (min), 95% CI -18.24 to 5.24; 6 studies, 671 participants; low-quality evidence); postoperative length of hospital stay (MD -0.95 (days), 95% CI -2.03 to 0.70; 4 studies, 500 participants; moderate-quality evidence); or stoma-related infections (RR 0.89, 95% CI 0.32 to 2.50; 6 studies, 472 participants; I² = 0%; low-quality evidence) between the two groups.We were unable to analyse mesh-related infections, quality of life, and rehospitalisation rate due to sparse data or because the outcome was not reported in the included studies.

AUTHORS' CONCLUSIONS

This Cochrane Review included 10 RCTs with a total of 844 participants. The review demonstrated a reduction in the incidence of parastomal hernia in people who had a prophylactic synthetic mesh placed at the time of the index operation compared to a standard ostomy formation. However, our confidence in this estimate is low due to the presence of a large degree of clinical heterogeneity, as well as high variability in follow-up duration and technique of parastomal herniation detection. We found the rate of stoma-related infection to be similar in both the intervention and control groups.

Abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis

BACKGROUND

Appendectomy, the surgical removal of the appendix, is performed primarily for acute appendicitis. Patients who undergo appendectomy for complicated appendicitis, defined as gangrenous or perforated appendicitis, are more likely to suffer from postoperative complications. The routine use of abdominal drainage to reduce postoperative complications after appendectomy for complicated appendicitis is controversial.This is an update of the review first published in 2015.

OBJECTIVES

To assess the safety and efficacy of abdominal drainage to prevent intra-peritoneal abscess after open appendectomy for complicated appendicitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 6), Ovid MEDLINE (1946 to 30 June 2017), Ovid Embase (1974 to 30 June 2017), Science Citation Index Expanded (1900 to 30 June 2017), World Health Organization International Clinical Trials Registry Platform (30 June 2017), ClinicalTrials.gov (30 June 2017) and Chinese Biomedical Literature Database (CBM) (1978 to 30 June 2017).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared abdominal drainage and no drainage in people undergoing emergency open appendectomy for complicated appendicitis.

DATA COLLECTION AND ANALYSIS

Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio for very rare outcomes), and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence.

MAIN RESULTS

We included six RCTs (521 participants), comparing abdominal drainage and no drainage in patients undergoing emergency open appendectomy for complicated appendicitis. The studies were conducted in North America, Asia and Africa. The majority of the participants had perforated appendicitis with local or general peritonitis. All participants received antibiotic regimens after open appendectomy. None of the trials was at low risk of bias.There was insufficient evidence to determine the effects of abdominal drainage and no drainage on intra-peritoneal abscess at 14 days (RR 1.23, 95% CI 0.47 to 3.21; 5 RCTs; 453 participants; very low-quality evidence) or for wound infection at 14 days (RR 2.01, 95% CI 0.88 to 4.56; 5 RCTs; 478 participants; very low-quality evidence). The increased risk of 30-day overall complication rate (morbidity) in the drainage group was rated as very low-quality evidence (RR 6.67, 95% CI 2.13 to 20.87; 1 RCT; 90 participants). There were seven deaths in the drainage group (N = 183) compared to one in the no drainage group (N = 180), equating to an increase in the risk of 30-day mortality from 0.6% to 2.7% (Peto odds ratio (OR) 4.88, 95% CI 1.18 to 20.09; 4 RCTs; 363 participants; moderate-quality evidence). There is 'very low-quality' evidence that drainage increases hospital stay compared to the no drainage group by 2.17 days (95% CI 1.76 to 2.58; 3 RCTs; 298 participants).Other outlined outcomes, hospital costs, pain, and quality of life, were not reported in any of the included studies.

AUTHORS' CONCLUSIONS

The quality of the current evidence is very low. The effect of abdominal drainage on the prevention of intra-peritoneal abscess or wound infection after open appendectomy is uncertain for patients with complicated appendicitis. The increased rates for overall complication rate and hospital stay for the drainage group compared to no drainage group is also subject to great uncertainty. Thus, there is no evidence for any clinical improvement by using abdominal drainage in patients undergoing open appendectomy for complicated appendicitis. The increased risk of mortality with drainage comes from eight deaths observed in just under 400 people recruited to the studies. Larger studies are needed to determine the effects of drainage on morbidity and mortality outcomes more reliably.

Laparoscopic versus open resection for sigmoid diverticulitis

BACKGROUND

Diverticular disease is a common condition in Western industrialised countries. Most individuals remain asymptomatic throughout life; however, 25% experience acute diverticulitis. The standard treatment for acute diverticulitis is open surgery. Laparoscopic surgery - a minimal-access procedure - offers an alternative approach to open surgery, as it is characterised by reduced operative stress that may translate into shorter hospitalisation and more rapid recovery, as well as improved quality of life.

OBJECTIVES

To evaluate the effectiveness of laparoscopic surgical resection compared with open surgical resection for individuals with acute sigmoid diverticulitis.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2) in the Cochrane Library; Ovid MEDLINE (1946 to 23 February 2017); Ovid Embase (1974 to 23 February 2017); clinicaltrials.gov (February 2017); and the World Health Organization (WHO) International Clinical Trials Registry (February 2017). We reviewed the bibliographies of identified trials to search for additional studies.

SELECTION CRITERIA

We included randomised controlled trials comparing elective or emergency laparoscopic sigmoid resection versus open surgical resection for acute sigmoid diverticulitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the domains of risk of bias from each included trial, and extracted data. For dichotomous outcomes, we calculated risk ratios (RRs) with 95% confidence intervals (CIs). For continuous outcomes, we planned to calculate mean differences (MDs) with 95% CIs for outcomes such as hospital stay, and standardised mean differences (SMDs) with 95% CIs for quality of life and global rating scales, if researchers used different scales.

MAIN RESULTS

Three trials with 392 participants met the inclusion criteria. Studies were conducted in three European countries (Switzerland, Netherlands, and Germany). The median age of participants ranged from 62 to 66 years; 53% to 64% were female. Inclusion criteria differed among studies. One trial included participants with Hinchey I characteristics as well as those who underwent Hartmann's procedure; the second trial included only participants with "a proven stage II/III disease according to the classification of Stock and Hansen"; the third trial considered for inclusion patients with "diverticular disease of sigmoid colon documented by colonoscopy and 2 episodes of uncomplicated diverticulitis, one at least being documented with CT scan, 1 episode of complicated diverticulitis, with a pericolic abscess (Hinchey stage I) or pelvic abscess (Hinchey stage II) requiring percutaneous drainage."We determined that two studies were at low risk of selection bias; two that reported considerable dropouts were at high risk of attrition bias; none reported blinding of outcome assessors (unclear detection bias); and all were exposed to performance bias owing to the nature of the intervention.Available low-quality evidence suggests that laparoscopic surgical resection may lead to little or no difference in mean hospital stay compared with open surgical resection (3 studies, 360 participants; MD -0.62 (days), 95% CI -2.49 to 1.25; I² = 0%).Low-quality evidence suggests that operating time was longer in the laparoscopic surgery group than in the open surgery group (3 studies, 360 participants; MD 49.28 (minutes), 95% CI 40.64 to 57.93; I² = 0%).We are uncertain whether laparoscopic surgery improves postoperative pain between day 1 and day 3 more effectively than open surgery. Low-quality evidence suggests that laparoscopic surgery may improve postoperative pain at the fourth postoperative day more effectively than open surgery (2 studies, 250 participants; MD = -0.65, 95% CI -1.04 to -0.25).Researchers reported quality of life differently across trials, hindering the possibility of meta-analysis. Low-quality evidence from one trial using the Short Form (SF)-36 questionnaire six weeks after surgery suggests that laparoscopic intervention may improve quality of life, whereas evidence from two other trials using the European Organization for Research and Treatment of Cancer core quality of life questionnaire (EORTC QLQ-C30) v3 and the Gastrointestinal Quality of Life Index score, respectively, suggests that laparoscopic surgery may make little or no difference in improving quality of life compared with open surgery.We are uncertain whether laparoscopic surgery improves the following outcomes: 30-day postoperative mortality, early overall morbidity, major and minor complications, surgical complications, postoperative times to liquid and solid diets, and reoperations due to anastomotic leak.

AUTHORS' CONCLUSIONS

Results from the present comprehensive review indicate that evidence to support or refute the safety and effectiveness of laparoscopic surgery versus open surgical resection for treatment of patients with acute diverticular disease is insufficient. Well-designed trials with adequate sample size are needed to investigate the efficacy of laparoscopic surgery towards important patient-oriented (e.g. postoperative pain) and health system-oriented outcomes (e.g. mean hospital stay).

Closure methods of the appendix stump for complications during laparoscopic appendectomy

BACKGROUND

Laparoscopic appendectomy is amongst the most common general surgical procedures performed in the developed world. Arguably, the most critical part of this procedure is effective closure of the appendix stump to prevent catastrophic intra-abdominal complications from a faecal leak into the abdominal cavity. A variety of methods to close the appendix stump are used worldwide; these can be broadly divided into traditional ligatures (such as intracorporeal or extracorporeal ligatures or Roeder loops) and mechanical devices (such as stapling devices, clips, or electrothermal devices). However, the optimal method remains unclear.

OBJECTIVES

To compare all surgical techniques now used for appendix stump closure during laparoscopic appendectomy.

SEARCH METHODS

In June 2017, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 6) in the Cochrane Library, MEDLINE Ovid (1946 to 14 June 2017), Embase Ovid (1974 to 14 June 2017), Science Citation Index - Expanded (14 June 2017), China Biological Medicine Database (CBM), the World Health Organization International Trials Registry Platform search portal, ClinicalTrials.gov, Current Controlled Trials, the Chinese Clinical Trials Register, and the EU Clinical Trials Register (all in June 2017). We searched the reference lists of relevant publications as well as meeting abstracts and Conference Proceedings Citation Index to look for additional relevant clinical trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared mechanical appendix stump closure (stapler, clips, or electrothermal devices) versus ligation (Endoloop, Roeder loop, or intracorporeal knot techniques) for uncomplicated appendicitis.

DATA COLLECTION AND ANALYSIS

Two review authors identified trials for inclusion, collected data, and assessed risk of bias independently. We performed the meta-analysis using Review Manager 5. We calculated the odds ratio (OR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs).

MAIN RESULTS

We included eight randomised studies encompassing 850 participants. Five studies compared titanium clips versus ligature, two studies compared an endoscopic stapler device versus ligature, and one study compared an endoscopic stapler device, titanium clips, and ligature. In our analyses of primary outcomes, we found no differences in total complications (OR 0.97, 95% CI 0.27 to 3.50, 8 RCTs, very low-quality evidence), intraoperative complications (OR 0.93, 95% CI 0.34 to 2.55, 8 RCTs, very low-quality evidence), or postoperative complications (OR 0.80, 95% CI 0.21 to 3.13, 8 RCTs, very low-quality evidence) between ligature and all types of mechanical devices. However, our analyses of secondary outcomes revealed that use of mechanical devices saved approximately nine minutes of total operating time when compared with use of a ligature (mean difference (MD) -9.04 minutes, 95% CI -12.97 to -5.11 minutes, 8 RCTs, very low-quality evidence). However, this finding did not translate into a clinically or statistically significant reduction in inpatient hospital stay (MD 0.02 days, 95% CI -0.12 to 0.17 days, 8 RCTs, very low-quality evidence). Available information was insufficient for reliable comparison of total hospital costs and postoperative pain/quality of life between the two approaches. Overall, evidence across all analyses was of very low quality, with substantial potential for confounding factors. Given the limitations of all studies in terms of bias and the low quality of available evidence, a clear conclusion regarding superiority of any one particular type of mechanical device over another is not possible.

AUTHORS' CONCLUSIONS

Evidence is insufficient at present to advocate omission of conventional ligature-based appendix stump closure in favour of any single type of mechanical device over another in uncomplicated appendicitis.

Closure methods for laparotomy incisions for preventing incisional hernias and other wound complications

BACKGROUND

Surgeons who perform laparotomy have a number of decisions to make regarding abdominal closure. Material and size of potential suture types varies widely. In addition, surgeons can choose to close the incision in anatomic layers or mass ('en masse'), as well as using either a continuous or interrupted suturing technique, of which there are different styles of each. There is ongoing debate as to which suturing techniques and suture materials are best for achieving definitive wound closure while minimising the risk of short- and long-term complications.

OBJECTIVES

The objectives of this review were to identify the best available suture techniques and suture materials for closure of the fascia following laparotomy incisions, by assessing the following comparisons: absorbable versus non-absorbable sutures; mass versus layered closure; continuous versus interrupted closure techniques; monofilament versus multifilament sutures; and slow absorbable versus fast absorbable sutures. Our objective was not to determine the single best combination of suture material and techniques, but to compare the individual components of abdominal closure.

SEARCH METHODS

On 8 February 2017 we searched CENTRAL, MEDLINE, Embase, two trials registries, and Science Citation Index. There were no limitations based on language or date of publication. We searched the reference lists of all included studies to identify trials that our searches may have missed.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared suture materials or closure techniques, or both, for fascial closure of laparotomy incisions. We excluded trials that compared only types of skin closures, peritoneal closures or use of retention sutures.

DATA COLLECTION AND ANALYSIS

We abstracted data and assessed the risk of bias for each trial. We calculated a summary risk ratio (RR) for the outcomes assessed in the review, all of which were dichotomous. We used random-effects modelling, based on the heterogeneity seen throughout the studies and analyses. We completed subgroup analysis planned a priori for each outcome, excluding studies where interventions being compared differed by more than one component, making it impossible to determine which variable impacted on the outcome, or the possibility of a synergistic effect. We completed sensitivity analysis, excluding trials with at least one trait with high risk of bias. We assessed the quality of evidence using the GRADEpro guidelines.

MAIN RESULTS

Fifty-five RCTs with a total of 19,174 participants met the inclusion criteria and were included in the meta-analysis. Included studies were heterogeneous in the type of sutures used, methods of closure and patient population. Many of the included studies reported multiple comparisons.For our primary outcome, the proportion of participants who developed incisional hernia at one year or more of follow-up, we did not find evidence that suture absorption (absorbable versus non-absorbable sutures, RR 1.07, 95% CI 0.86 to 1.32, moderate-quality evidence; or slow versus fast absorbable sutures, RR 0.81, 95% CI 0.63 to 1.06, moderate-quality evidence), closure method (mass versus layered, RR 1.92, 95% CI 0.58 to 6.35, very low-quality evidence) or closure technique (continuous versus interrupted, RR 1.01, 95% CI 0.76 to 1.35, moderate-quality evidence) resulted in a difference in the risk of incisional hernia. We did, however, find evidence to suggest that monofilament sutures reduced the risk of incisional hernia when compared with multifilament sutures (RR 0.76, 95% CI 0.59 to 0.98, I² = 30%, moderate-quality evidence).For our secondary outcomes, we found that none of the interventions reduced the risk of wound infection, whether based on suture absorption (absorbable versus non-absorbable sutures, RR 0.99, 95% CI 0.84 to 1.17, moderate-quality evidence; or slow versus fast absorbable sutures, RR 1.16, 95% CI 0.85 to 1.57, moderate-quality evidence), closure method (mass versus layered, RR 0.93, 95% CI 0.67 to 1.30, low-quality evidence) or closure technique (continuous versus interrupted, RR 1.13, 95% CI 0.96 to 1.34, moderate-quality evidence).Similarily, none of the interventions reduced the risk of wound dehiscence whether based on suture absorption (absorbable versus non-absorbable sutures, RR 0.78, 95% CI 0.55 to 1.10, moderate-quality evidence; or slow versus fast absorbable sutures, RR 1.55, 95% CI 0.92 to 2.61, moderate-quality evidence), closure method (mass versus layered, RR 0.69, 95% CI 0.31 to 1.52, moderate-quality evidence) or closure technique (continuous versus interrupted, RR 1.21, 95% CI 0.90 to 1.64, moderate-quality evidence).Absorbable sutures, compared with non-absorbable sutures (RR 0.49, 95% CI 0.26 to 0.94, low-quality evidence) reduced the risk of sinus or fistula tract formation. None of the other comparisons showed a difference (slow versus fast absorbable sutures, RR 0.88, 95% CI 0.05 to 16.05, very low-quality evidence; mass versus layered, RR 0.49, 95% CI 0.15 to 1.62, low-quality evidence; continuous versus interrupted, RR 1.51, 95% CI 0.64 to 3.61, very low-quality evidence).

AUTHORS' CONCLUSIONS

Based on this moderate-quality body of evidence, monofilament sutures may reduce the risk of incisional hernia. Absorbable sutures may also reduce the risk of sinus or fistula tract formation, but this finding is based on low-quality evidence.We had serious concerns about the design or reporting of several of the 55 included trials. The comparator arms in many trials differed by more than one component, making it impossible to attribute differences between groups to any one component. In addition, the patient population included in many of the studies was very heterogeneous. Trials included both emergency and elective cases, different types of disease pathology (e.g. colon surgery, hepatobiliary surgery, etc.) or different types of incisions (e.g. midline, paramedian, subcostal).Consequently, larger, high-quality trials to further address this clinical challenge are warranted. Future studies should ensure that proper randomisation and allocation techniques are performed, wound assessors are blinded, and that the duration of follow-up is adequate. It is important that only one type of intervention is compared between groups. In addition, a homogeneous patient population would allow for a more accurate assessment of the interventions.

Mesalamine (5-ASA) for the prevention of recurrent diverticulitis

BACKGROUND

Diverticular disease is a common condition that increases in prevalence with age. Recent theories on the pathogenesis of diverticular inflammation have implicated chronic inflammation similar to that seen in ulcerative colitis. Mesalamine, or 5-aminosalicylic acid (5-ASA), is a mainstay of therapy for individuals with ulcerative colitis. Accordingly, 5-ASA has been studied for prevention of recurrent diverticulitis.

OBJECTIVES

To evaluate the efficacy of mesalamine (5-ASA) for prevention of recurrent diverticulitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8), in the Cochrane Library; Ovid MEDLINE (from 1950 to 9 September 2017); Ovid Embase (from 1974 to 9 September 2017); and two clinical trials registries for ongoing trials - Clinicaltrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform database (9 September 2017).We also searched proceedings from major gastrointestinal conferences - Digestive Disease Week (DDW), United European Gastroenterology Week (UEGW), and the American College of Gastroenterology (ACG) Annual Scientific Meeting - from 2010 to September 2017. In addition, we scanned reference lists from eligible publications, and we contacted corresponding authors to ask about additional trials.

SELECTION CRITERIA

We included randomised controlled clinical trials comparing the efficacy of 5-ASA versus placebo or another active drug for prevention of recurrent diverticulitis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as defined by Cochrane. Three review authors assessed eligibility for inclusion. Two review authors selected studies, extracted data, and assessed methodological quality independently. We calculated risk ratios (RRs) for prevention of diverticulitis recurrence using an intention-to-treat principle and random-effects models. We assessed heterogeneity using criteria for Chi2 (P < 0.10) and I2 tests (> 50%). To explore sources of heterogeneity, we conducted a priori subgroup analyses. To assess the robustness of our results, we carried out sensitivity analyses using different summary statistics (RR vs odds ratio (OR)) and meta-analytical models (fixed-effect vs random-effects).

MAIN RESULTS

We included in this review seven studies with a total of 1805 participants. We judged all seven studies to have unclear or high risk of bias. Investigators found no evidence of an effect when comparing 5-ASA versus control for prevention of recurrent diverticulitis (31.3% vs 29.8%; RR 0.69, 95% confidence interval (CI) 0.43 to 1.09); very low quality of evidence).Five of the seven studies provided data on adverse events of 5-ASA therapy. The most commonly reported side effects were gastrointestinal symptoms (epigastric pain, nausea, and diarrhoea). No significant difference was seen between 5-ASA and control (67.8% vs 64.6%; RR 0.98, 95% CI 0.91 to 1.06; P = 0.63; moderate quality of evidence), nor was significant heterogeneity observed (I2 = 0%; P = 0.50).

AUTHORS' CONCLUSIONS

The effects of 5-ASA on recurrence of diverticulitis are uncertain owing to the small number of heterogenous trials included in this review. Rates of recurrent diverticulitis were similar among participants using 5-ASA and control participants. Effective medical strategies for prevention of recurrent diverticulitis are needed, and further randomised, double-blinded, placebo-controlled trials of rigorous design are warranted to specify the effects of 5-ASA (mesalamine) in the management of diverticulitis.

Oral versus intravenous fluoropyrimidines for colorectal cancer

BACKGROUND

Patients prefer oral to intravenous (IV) palliative chemotherapy, provided that oral therapy is not less effective. We compared the efficacy and safety of oral and IV fluoropyrimidines for treatment of colorectal cancer (CRC).

OBJECTIVES

To compare the effects of oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5), along with OVID MEDLINE, OVID Embase, and Web of Science databases, in June 2016. We also searched five clinical trials registers, several conference proceedings, and reference lists from study reports and systematic reviews. We contacted pharmaceutical companies to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.

DATA COLLECTION AND ANALYSIS

Three review authors extracted data and assessed risk of bias independently. We assessed the seven domains in the Cochrane 'Risk of bias' tool and three additional domains: schedules of outcome assessment and/or follow-up; use of intention-to-treat analysis; and baseline comparability of treatment arms.

MAIN RESULTS

We included nine RCTs (total of 10,918 participants) that examined treatment with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy. We included 35 RCTs (total of 12,592 participants) that examined treatment with palliative intent for inoperable advanced or metastatic CRC with chemotherapy (31 first-line studies, two second-line studies, and two studies of first- or second-line chemotherapy). All studies included male and female participants, and no studies included participants younger than 18 years of age. Patients treated with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy • Disease-free survival (DFS): DFS did not differ between participants treated with oral versus IV fluoropyrimidines (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.87 to 1.00; seven studies, 8903 participants; moderate-quality evidence).• Overall survival (OS): OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 0.92, 95% CI 0.84 to 1.00; seven studies, 8902 participants analysed; high-quality evidence).• Grade ≥ 3 adverse events (AEs): Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (odds ratio (OR) 0.14, 95% CI 0.11 to 0.16; seven studies, 8087 participants; moderate-quality evidence), stomatitis (OR 0.21, 95% CI 0.14 to 0.30; five studies, 4212 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.82, 95% CI 0.74 to 0.90; five studies, 7741 participants; low-quality evidence). There was more grade ≥ 3 hand foot syndrome (OR 4.59, 95% CI 2.97 to 7.10; five studies, 5731 participants; low-quality evidence) in patients treated with oral fluoropyrimidines. There were no differences between participants treated with oral versus IV fluoropyrimidines in occurrence of grade ≥ 3 diarrhoea (OR 1.12, 95% CI 0.99 to 1.25; nine studies, 9551 participants; very low-quality evidence), febrile neutropenia (OR 0.59, 95% CI 0.18 to 1.90; four studies, 2925 participants; low-quality evidence), vomiting (OR 1.05, 95% CI 0.83 to 1.34; eight studies, 9385 participants; low-quality evidence), nausea (OR 1.21, 95% CI 0.97 to 1.51; seven studies, 9233 participants; low-quality evidence), mucositis (OR 0.64, 95% CI 0.25 to 1.62; four studies, 2233 participants; very low-quality evidence), and hyperbilirubinaemia (OR 1.67, 95% CI 0.52 to 5.38; three studies, 2757 participants; very low-quality evidence). Patients treated with palliative intent for inoperable advanced or metastatic CRC with chemotherapy • Progression-free survival (PFS): Overall, PFS was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.06, 95% CI 1.02 to 1.11; 23 studies, 9927 participants; moderate-quality evidence). Whilst PFS was worse in participants treated with oral compared with IV fluoropyrimidines when UFT/Ftorafur or eniluracil with oral 5-fluorouracil (5-FU) was used, PFS did not differ between individuals treated with oral versus IV fluoropyrimidines when capecitabine, doxifluridine, or S-1 was used.• OS: Overall, OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 1.02, 95% CI 0.99 to 1.05; 29 studies, 12,079 participants; high-quality evidence). OS was inferior in participants treated with oral versus IV fluoropyrimidines when eniluracil with oral 5-fluorouracil (5-FU) was used.• Time to progression (TTP): TTP was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.07, 95% CI 1.01 to 1.14; six studies, 1970 participants; moderate-quality evidence).• Objective response rate (ORR): ORR did not differ between participants treated with oral versus IV fluoropyrimidines (OR 0.98, 95% CI 0.90 to 1.06; 32 studies, 11,115 participants; moderate-quality evidence).• Grade ≥ 3 AEs: Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (OR 0.17, 95% CI 0.15 to 0.18; 29 studies, 11,794 participants; low-quality evidence), febrile neutropenia (OR 0.27, 95% CI 0.21 to 0.36; 19 studies, 9407 participants; moderate-quality evidence), stomatitis (OR 0.26, 95% CI 0.20 to 0.33; 21 studies, 8718 participants; low-quality evidence), mucositis (OR 0.17, 95% CI 0.12 to 0.24; 12 studies, 4962 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.83, 95% CI 0.74 to 0.94; 14 studies, 5436 participants; low-quality evidence). There was more grade ≥ 3 diarrhoea (OR 1.66, 95% CI 1.50 to 1.84; 30 studies, 11,997 participants; low-quality evidence) and hand foot syndrome (OR 3.92, 95% CI 2.84 to 5.43; 18 studies, 6481 participants; moderate-quality evidence) in the oral fluoropyrimidine arm. There were no differences between oral and IV fluoropyrimidine arms in terms of grade ≥ 3 vomiting (OR 1.18, 95% CI 1.00 to 1.40; 23 studies, 9528 participants; low-quality evidence), nausea (OR 1.16, 95% CI 0.99 to 1.36; 25 studies, 9796 participants; low-quality evidence), and hyperbilirubinaemia (OR 1.62, 95% CI 0.99 to 2.64; nine studies, 2699 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

Results of this review should provide confidence that treatment for CRC with most of the oral fluoropyrimidines commonly used in current clinical practice is similarly efficacious to treatment with IV fluoropyrimidines. Treatment with eniluracil with oral 5-FU was associated with inferior PFS and OS among participants treated with palliative intent for CRC, and eniluracil is no longer being developed. Oral and IV fluoropyrimidines have different patterns of side effects; future research may focus on determining the basis for these differences.

Epidermal growth factor receptor (EGFR) inhibitors for metastatic colorectal cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) inhibitors prevent cell growth and have shown benefit in the treatment of metastatic colorectal cancer, whether used as single agents or in combination with chemotherapy. Clear benefit has been shown in trials of EGFR monoclonal antibodies (EGFR MAb) but not EGFR tyrosine kinase inhibitors (EGFR TKI). However, there is ongoing debate as to which patient populations gain maximum benefit from EGFR inhibition and where they should be used in the metastatic colorectal cancer treatment paradigm to maximise efficacy and minimise toxicity.

OBJECTIVES

To determine the efficacy, safety profile, and potential harms of EGFR inhibitors in the treatment of people with metastatic colorectal cancer when given alone, in combination with chemotherapy, or with other biological agents.The primary outcome of interest was progression-free survival; secondary outcomes included overall survival, tumour response rate, quality of life, and adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library, Issue 9, 2016; Ovid MEDLINE (from 1950); and Ovid Embase (from 1974) on 9 September 2016; and ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) on 14 March 2017. We also searched proceedings from the major oncology conferences ESMO, ASCO, and ASCO GI from 2012 to December 2016. We further scanned reference lists from eligible publications and contacted corresponding authors for trials for further information where needed.

SELECTION CRITERIA

We included randomised controlled trials on participants with metastatic colorectal cancer comparing: 1) the combination of EGFR MAb and 'standard therapy' (whether chemotherapy or best supportive care) to standard therapy alone, 2) the combination of EGFR TKI and standard therapy to standard therapy alone, 3) the combination of EGFR inhibitor (whether MAb or TKI) and standard therapy to another EGFR inhibitor (or the same inhibitor with a different dosing regimen) and standard therapy, or 4) the combination of EGFR inhibitor (whether MAb or TKI), anti-angiogenic therapy, and standard therapy to anti-angiogenic therapy and standard therapy alone.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures defined by Cochrane. Summary statistics for the endpoints used hazard ratios (HR) with 95% confidence intervals (CI) for overall survival and progression-free survival, and odds ratios (OR) for response rate (RR) and toxicity. Subgroup analyses were performed by Kirsten rat sarcoma viral oncogene homolog (KRAS) and neuroblastoma RAS viral (V-Ras) oncogene homolog (NRAS) status - firstly by status of KRAS exon 2 testing (mutant or wild type) and also by status of extended KRAS/NRAS testing (any mutation present or wild type).

MAIN RESULTS

We identified 33 randomised controlled trials for analysis (15,025 participants), including trials of both EGFR MAb and EGFR TKI. Looking across studies, significant risk of bias was present, particularly with regard to the risk of selection bias (15/33 unclear risk, 1/33 high risk), performance bias (9/33 unclear risk, 9/33 high risk), and detection bias (7/33 unclear risk, 11/33 high risk).The addition of EGFR MAb to standard therapy in the KRAS exon 2 wild-type population improves progression-free survival (HR 0.70, 95% CI 0.60 to 0.82; high-quality evidence), overall survival (HR 0.88, 95% CI 0.80 to 0.98; high-quality evidence), and response rate (OR 2.41, 95% CI 1.70 to 3.41; high-quality evidence). We noted evidence of significant statistical heterogeneity in all three of these analyses (progression-free survival: I2 = 76%; overall survival: I2 = 40%; and response rate: I2 = 77%), likely due to pooling of studies investigating EGFR MAb use in different lines of therapy. Rates of overall grade 3 to 4 toxicity, diarrhoea, and rash were increased (moderate-quality evidence for all three outcomes), but there was no evidence for increased rates of neutropenia.For the extended RAS wild-type population (no mutations in KRAS or NRAS), addition of EGFR MAb improved progression-free survival (HR 0.60, 95% CI 0.48 to 0.75; moderate-quality evidence) and overall survival (HR 0.77, 95% CI 0.67 to 0.88; high-quality evidence). Response rate was also improved (OR 4.28, 95% CI 2.61 to 7.03; moderate-quality evidence). We noted significant statistical heterogeneity in the progression-free survival analysis (I2 = 61%), likely due to the pooling of studies combining EGFR MAb with chemotherapy with monotherapy studies.We observed no evidence of a statistically significant difference when EGFR MAb was compared to bevacizumab, in progression-free survival (HR 1.02, 95% CI 0.93 to 1.12; high quality evidence) or overall survival (HR 0.84, 95% CI 0.70 to 1.01; moderate-quality evidence). We noted significant statistical heterogeneity in the overall survival analysis (I2 = 51%), likely due to the pooling of first-line and second-line studies.The addition of EGFR TKI to standard therapy in molecularly unselected participants did not show benefit in limited data sets (meta-analysis not performed). The addition of EGFR MAb to bevacizumab plus chemotherapy in people with KRAS exon 2 wild-type metastatic colorectal cancer did not improve progression-free survival (HR 1.04, 95% CI 0.83 to 1.29; very low quality evidence), overall survival (HR 1.00, 95% CI 0.69 to 1.47; low-quality evidence), or response rate (OR 1.20, 95% CI 0.67 to 2.12; very low-quality evidence) but increased toxicity (OR 2.57, 95% CI 1.45 to 4.57; low-quality evidence). We noted significant between-study heterogeneity in most analyses.Scant information on quality of life was reported in the identified studies.

AUTHORS' CONCLUSIONS

The addition of EGFR MAb to either chemotherapy or best supportive care improves progression-free survival (moderate- to high-quality evidence), overall survival (high-quality evidence), and tumour response rate (moderate- to high-quality evidence), but may increase toxicity in people with KRAS exon 2 wild-type or extended RAS wild-type metastatic colorectal cancer (moderate-quality evidence). The addition of EGFR TKI to standard therapy does not improve clinical outcomes. EGFR MAb combined with bevacizumab is of no clinical value (very low-quality evidence). Future studies should focus on optimal sequencing and predictive biomarkers and collect quality of life data.

Gases for establishing pneumoperitoneum during laparoscopic abdominal surgery

BACKGROUND

This is an update of the review published in 2013.Laparoscopic surgery is now widely performed to treat various abdominal diseases. Currently, carbon dioxide is the most frequently used gas for insufflation of the abdominal cavity (pneumoperitoneum). Although carbon dioxide meets most of the requirements for pneumoperitoneum, the absorption of carbon dioxide may be associated with adverse events. People with high anaesthetic risk are more likely to experience cardiopulmonary complications and adverse events, for example hypercapnia and acidosis, which has to be avoided by hyperventilation. Therefore, other gases have been introduced as alternatives to carbon dioxide for establishing pneumoperitoneum.

OBJECTIVES

To assess the safety, benefits, and harms of different gases (i.e. carbon dioxide, helium, argon, nitrogen, nitrous oxide, and room air) used for establishing pneumoperitoneum in participants undergoing laparoscopic general abdominal or gynaecological pelvic surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 9), Ovid MEDLINE (1950 to September 2016), Ovid Embase (1974 to September 2016), Science Citation Index Expanded (1970 to September 2016), Chinese Biomedical Literature Database (CBM) (1978 to September 2016), ClinicalTrials.gov (September 2016), and World Health Organization International Clinical Trials Registry Platform (September 2016).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different gases for establishing pneumoperitoneum in participants (irrespective of age, sex, or race) undergoing laparoscopic abdominal or gynaecological pelvic surgery under general anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors identified the trials for inclusion, collected the data, and assessed the risk of bias independently. We performed the meta-analyses using Review Manager 5. We calculated risk ratio (RR) for dichotomous outcomes (or Peto odds ratio for very rare outcomes), and mean difference (MD) or standardised mean difference (SMD) for continuous outcomes with 95% confidence intervals (CI). We used GRADE to rate the quality of evidence, MAIN RESULTS: We included nine RCTs, randomising 519 participants, comparing different gases for establishing pneumoperitoneum: nitrous oxide (three trials), helium (five trials), or room air (one trial) was compared to carbon dioxide. Three trials randomised participants to nitrous oxide pneumoperitoneum (100 participants) or carbon dioxide pneumoperitoneum (96 participants). None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of nitrous oxide and carbon dioxide on cardiopulmonary complications (RR 2.00, 95% CI 0.38 to 10.43; two studies; 140 participants; very low quality of evidence), or surgical morbidity (RR 1.01, 95% CI 0.18 to 5.71; two studies; 143 participants; very low quality of evidence). There were no serious adverse events related to either nitrous oxide or carbon dioxide pneumoperitoneum (three studies; 196 participants; very low quality of evidence). We could not combine data from two trials (140 participants) which individually showed lower pain scores (a difference of about one visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain) with nitrous oxide pneumoperitoneum at various time points on the first postoperative day, and this was rated asvery low quality .Four trials randomised participants to helium pneumoperitoneum (69 participants) or carbon dioxide pneumoperitoneum (75 participants) and one trial involving 33 participants did not state the number of participants in each group. None of the trials was at low risk of bias. There was insufficient evidence to determine the effects of helium or carbon dioxide on cardiopulmonary complications (RR 1.46, 95% CI 0.35 to 6.12; three studies; 128 participants; very low quality of evidence) or pain scores (visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain; MD 0.49 cm, 95% CI -0.28 to 1.26; two studies; 108 participants; very low quality of evidence). There were three serious adverse events (subcutaneous emphysema) related to helium pneumoperitoneum (three studies; 128 participants; very low quality of evidence).One trial randomised participants to room air pneumoperitoneum (70 participants) or carbon dioxide pneumoperitoneum (76 participants). The trial was at unclear risk of bias. There were no cardiopulmonary complications or serious adverse events observed related to either room air or carbon dioxide pneumoperitoneum (both outcomes very low quality of evidence). The evidence of lower hospital costs and reduced pain during the first postoperative day with room air pneumoperitoneum compared with carbon dioxide pneumoperitoneum (a difference of about one visual analogue score on a scale of 1 to 10 with lower numbers indicating less pain, was rated as very low quality of evidence.

AUTHORS' CONCLUSIONS

The quality of the current evidence is very low. The effects of nitrous oxide and helium pneumoperitoneum compared with carbon dioxide pneumoperitoneum are uncertain. Evidence from one trial of small sample size suggests that room air pneumoperitoneum may decrease hospital costs in people undergoing laparoscopic abdominal surgery. The safety of nitrous oxide, helium, and room air pneumoperitoneum has yet to be established.Further trials on this topic are needed, and should compare various gases (i.e. nitrous oxide, helium, argon, nitrogen, and room air) with carbon dioxide under standard pressure pneumoperitoneum with cold gas insufflation for people with high anaesthetic risk. Future trials should include outcomes such as complications, serious adverse events, quality of life, and pain.

Early versus delayed appendicectomy for appendiceal phlegmon or abscess

BACKGROUND

Appendiceal phlegmon and abscess account for 2% to 10% of acute appendicitis. People with appendiceal phlegmon or abscess usually need an appendicectomy to relieve their symptoms and avoid complications. The timing of appendicectomy for appendiceal phlegmon or abscess is controversial.

OBJECTIVES

To assess the effects of early versus delayed appendicectomy for appendiceal phlegmon or abscess, in terms of overall morbidity and mortality.

SEARCH METHODS

We searched the Cochrane Library (CENTRAL; 2016, Issue 7), MEDLINE Ovid (1950 to 23 August 2016), Embase Ovid (1974 to 23 August 2016), Science Citation Index Expanded (1900 to 23 August 2016), and the Chinese Biomedical Literature Database (CBM) (1978 to 23 August 2016). We also searched the World Health Organization (WHO) International Clinical Trials Registry Platform search portal (23 August 2016) and ClinicalTrials.gov (23 August 2016) for ongoing trials.

SELECTION CRITERIA

We included all individual and cluster-randomised controlled trials, irrespective of language, publication status, or age of participants, comparing early versus delayed appendicectomy in people with appendiceal phlegmon or abscess.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We performed meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

We included two randomised controlled trials with a total of 80 participants in this review. 1. Early versus delayed open appendicectomy for appendiceal phlegmonForty participants (paediatric and adults) with appendiceal phlegmon were randomised either to early appendicectomy (appendicectomy as soon as appendiceal mass resolved within the same admission) (n = 20), or to delayed appendicectomy (initial conservative treatment followed by interval appendicectomy six weeks later) (n = 20). The trial was at high risk of bias. There was no mortality in either group. There is insufficient evidence to determine the effect of using either early or delayed open appendicectomy onoverall morbidity (RR 13.00; 95% CI 0.78 to 216.39; very low-quality evidence), the proportion of participants who developed wound infection (RR 9.00; 95% CI 0.52 to 156.91; very low quality evidence) or faecal fistula (RR 3.00; 95% CI 0.13 to 69.52; very low quality evidence). The quality of evidence for increased length of hospital stay and time away from normal activities in the early appendicectomy group (MD 6.70 days; 95% CI 2.76 to 10.64, and MD 5.00 days; 95% CI 1.52 to 8.48, respectively) is very low quality evidence. The trial reported neither quality of life nor pain outcomes. 2. Early versus delayed laparoscopic appendicectomy for appendiceal abscessForty paediatric participants with appendiceal abscess were randomised either to early appendicectomy (emergent laparoscopic appendicectomy) (n = 20) or to delayed appendicectomy (initial conservative treatment followed by interval laparoscopic appendicectomy 10 weeks later) (n = 20). The trial was at high risk of bias. The trial did not report on overall morbidity or complications. There was no mortality in either group. We do not have sufficient evidence to determine the effects of using either early or delayed laparoscopic appendicectomy for outcomes relating to hospital stay between the groups (MD -0.20 days; 95% CI -3.54 to 3.14; very low quality of evidence). Health-related quality of life was measured with the Pediatric Quality of Life Scale-Version 4.0 questionnaire (a scale of 0 to 100 with higher values indicating a better quality of life). Health-related quality of life score measured at 12 weeks after appendicectomy was higher in the early appendicectomy group than in the delayed appendicectomy group (MD 12.40 points; 95% CI 9.78 to 15.02) but the quality of evidence was very low. This trial reported neither the pain nor the time away from normal activities.

AUTHORS' CONCLUSIONS

It is unclear whether early appendicectomy prevents complications compared to delayed appendicectomy for people with appendiceal phlegmon or abscess. The evidence indicating increased length of hospital stay and time away from normal activities in people with early open appendicectomy is of very low quality. The evidence for better health-related quality of life following early laparoscopic appendicectomy compared with delayed appendicectomy is based on very low quality evidence. For both comparisons addressed in this review, data are sparse, and we cannot rule out significant benefits or harms of early versus delayed appendicectomy.Further trials on this topic are urgently needed and should specify a set of criteria for use of antibiotics, percutaneous drainage of the appendiceal abscess prior to surgery and resolution of the appendiceal phlegmon or abscess. Future trials should include outcomes such as time away from normal activities, quality of life and the length of hospital stay.

Management for intussusception in children

BACKGROUND

Intussusception is a common abdominal emergency in children with significant morbidity. Prompt diagnosis and management reduces associated risks and the need for surgical intervention. Despite widespread agreement on the use of contrast enema as opposed to surgery for initial management in most cases, debate persists on the appropriate contrast medium, imaging modality, pharmacological adjuvant, and protocol for delayed repeat enema, and on the best approach for surgical management for intussusception in children.

OBJECTIVES

To assess the safety and effectiveness of non-surgical and surgical approaches in the management of intussusception in children.

SEARCH METHODS

We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8) in the Cochrane Library; Ovid MEDLINE (1950 to September 2016); Ovid Embase (1974 to September 2016); Science Citation Index Expanded (via Web of Science) (1900 to September 2016); and BIOSIS Previews (1969 to September 2016).We examined the reference lists of all eligible trials to identify additional studies. To locate unpublished studies, we contacted content experts, searched the World Health Organization International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov (September 2016), and explored proceedings from meetings of the British Association of Paedatric Surgeons (BAPS), the American Soceity of Pediatric Surgery, and the World Congress of Pediatric Surgery.

SELECTION CRITERIA

We included all randomised controlled trials comparing contrast media, imaging modalities, pharmacological adjuvants, protocols for delayed repeat enema, and/or surgical approaches for the management of intussusception in children. We applied no language, publication date, or publication status restrictions.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted study selection and data extraction and assessed risk of bias using a standardised form. We resolved disagreements by consensus with a third review author when necessary. We reported dichotomous outcomes as risk ratios (RRs) with 95% confidence intervals (CIs). We analysed data on an intention-to-treat basis and evaluated the overall quality of evidence supporting the outcomes by using GRADE criteria.

MAIN RESULTS

We included six randomised controlled trials (RCTs) with a total of 822 participants. Two trials compared liquid enema reduction plus glucagon versus liquid enema alone. One trial compared liquid enema plus dexamethasone versus liquid enema alone. Another trial compared air enema plus dexamethasone versus air enema alone, and two trials compared use of liquid enema versus air enema. We identified three ongoing trials.We judged all included trials to be at risk of bias owing to omissions in reported methods. We judged five of six trials as having high risk of bias in at least one domain. Therefore, the quality of the evidence (GRADE) for outcomes was low. Interventions and data presentation varied greatly across trials; therefore meta-analysis was not possible for most review outcomes. Enema plus glucagon versus enema alone It is uncertain whether use of glucagon improves the rate of successful reduction of intussusception when compared with enema alone (reported in two trials, 218 participants; RR 1.09, 95% CI 0.94 to 1.26;low quality of evidence). No trials in this comparison reported on the number of children with bowel perforation(s) nor on the number of children with recurrent intussusception. Enema plus dexamethasone versus enema alone Use of the adjunct, dexamethasone, may be beneficial in reducing intussusception recurrence with liquid or air enema (two trials, 299 participants; RR 0.14, 95% CI 0.03 to 0.60; low quality of evidence). This equates to a number needed to treat for an additional beneficial outcome of 13 (95% CI 8 to 37). It is uncertain whether use of the adjunct, dexamethasone, improves the rate of successful reduction of intussusception when compared with enema alone (reported in two trials, 356 participants; RR 1.01, 95% CI 0.92 to 1.10;low quality of evidence). Air enema versus liquid enema Air enema may be more successful than liquid enema for reducing intussusception (two trials, 199 participants; RR 1.28, 95% CI 1.10 to 1.49; low quality of evidence). This equates to a number needed to treat for an additional beneficial outcome of 6 (95% CI 4 to 19). No trials in this comparison reported on the number of children with bowel perforation(s) or on the number of children with recurrent intussusception nor any intraoperative complications, such as bowel perforation, or other adverse effects. Only one trial reported postoperative complications, but owing to the method of reporting used, a quantitative analysis was not possible. We identified no studies that exclusively evaluated surgical interventions for management of intussusception.

AUTHORS' CONCLUSIONS

This review identified a small number of trials that assessed a variety of interventions. All included trials provided evidence of low quality and were subject to serious concerns about imprecision, high risk of bias, or both. Air enema may be superior to liquid enema for successfully reducing intussusception in children; however, this finding is based on a few studies including small numbers of participants. Dexamethasone as an adjuvant may be more effective in reducing intussusception recurrence rates following air enema or liquid enema, but these results are also based on a few studies of small numbers of participants. This review highlights several points that need to be addressed in future studies, including reducing the risk of bias and including relevant outcomes. Specifically, surgical trials are lacking, and future research is needed to address this evidence gap.

Mesh fixation with glue versus suture for chronic pain and recurrence in Lichtenstein inguinal hernioplasty

BACKGROUND

Chronic pain following mesh-based inguinal hernia repair is frequently reported, and has a significant impact on quality of life. Whether mesh fixation with glue can reduce chronic pain without increasing the recurrence rate is still controversial.

OBJECTIVES

To determine whether tissue adhesives can reduce postoperative complications, especially chronic pain, with no increase in recurrence rate, compared with sutures for mesh fixation in Lichtenstein hernia repair.

SEARCH METHODS

We searched the following electronic databases with no language restrictions: the Cochrane Central Register of Controlled Trials (CENTRAL; issue 4, 2016) in the Cochrane Library (searched 11 May 2016), MEDLINE Ovid (1986 to 11 May 2016), Embase Ovid (1986 to 11 May 2016), Science Citation Index (Web of Science) (1986 to 11 May 2016), CBM (Chinese Biomedical Database), CNKI (China National Knowledge Infrastructure), VIP (a full-text database in China), Wanfang databases. We also checked reference lists of identified papers (included studies and relevant reviews).

SELECTION CRITERIA

We included all randomised and quasi-randomised controlled trials comparing glue versus sutures for mesh fixation in Lichtenstein hernia repair. Cluster-RCTs were also eligible.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed the risk of bias independently. Dichotomous outcomes were expressed as odds ratio (OR) with 95% confidence intervals (CI). Continuous outcomes were expressed as mean differences (MD) with 95% CIs.

MAIN RESULTS

Twelve trials with a total of 1932 participants were included in this review. The overall postoperative chronic pain in the glue group was reduced by 37% (OR 0.63, 95% CI 0.44 to 0.91; 10 studies, 1418 participants, low-quality evidence) compared with the suture group. However, the results changed when we conducted subgroup analysis with regard to the type of mesh. Subgroup analysis of included studies using lightweight mesh showed the reduction of chronic pain was less profound and insignificant (OR 0.77, 95% CI 0.50 to 1.17). Subgroup analysis of included studies using heavyweight mesh resulted in a significant benefit from the fixation with glue (OR 0.38, 95% CI 0.17 to 0.82).Hernia recurrence was similar between the two groups (OR 1.44, 95% CI 0.63 to 3.28; 12 studies, 1932 participants, low-quality evidence). Fixation with glue was superior to suture regarding duration of the operation (MD -3.13, 95% CI -4.48 to -1.78; 9 studies, 1790 participants, low-quality evidence); haematoma (OR 0.52, 95% CI 0.31 to 0.86; 10 studies, 1384 participants, moderate-quality evidence); and recovery time to daily activities (MD -1.26, 95% CI -1.89 to -0.63; 3 studies, 403 participants, low-quality evidence).We also investigated adverse events. There were no significant differences between the two groups. For superficial wound infection pooled analyses showed OR 1.23, 95% CI 0.37 to 4.11; 7 studies, 763 participants (low-quality evidence); for mesh/deep infection OR 0.67, 95% CI 0.16 to 2.83; 8 studies, 1393 participants (low-quality evidence). Furthermore, we investigated seroma (a postoperative swelling caused by fluid) (OR 0.83, 95% CI 0.51 to 1.33); and persisting numbness (OR 0.81, 95% CI 0.57 to 1.14).Finally, six trials involving 1009 participants reported postoperative length of stay, resulting in non-significant difference between the two groups (MD -0.12, 95% CI: -0.35 to 0.10)Due to the lack of data, it was impossible to draw any distinction between synthetic glue and biological glue.Eight out of 12 trials showed high risk of bias in at least one of the investigated domains. Two studies were quasi-randomised controlled trials and the allocation sequence of one trial was not concealed. Nearly half of the included trials either did not provide adequate information or had high risk of bias regarding blinding processes. The risk of bias for incomplete outcome data of all the included studies varied from low to high risk of bias. Two trials did not report on some important outcomes. One study was funded by the manufacturer producing the fibrin sealant. Therefore, according to the 'Summary of findings' tables, the quality of the evidence (GRADE) for the outcomes is moderate to low.

AUTHORS' CONCLUSIONS

Based on the short-term results, glue may reduce postoperative chronic pain and not simultaneously increase the recurrence rate, compared with sutures for mesh fixation in Lichtenstein hernia repair. Glue may therefore be a sensible alternative to suture for mesh fixation in Lichtenstein repair. Larger trials with longer follow-up and high quality are warranted. The difference between synthetic glue and biological glue should also be assessed in the future.

Second-line systemic therapy for metastatic colorectal cancer

BACKGROUND

The therapeutic management of people with metastatic colorectal cancer (CRC) who did not respond to first-line treatment represents a formidable challenge.

OBJECTIVES

To determine the efficacy and toxicity of second-line systemic therapy in people with metastatic CRC.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 4), Ovid MEDLINE (1950 to May 2016), Ovid MEDLINE In-process & Other Non-Indexed Citations (1946 to May 2016) and Ovid Embase (1974 to May 2016). There were no language or date of publication restrictions.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the efficacy (survival, tumour response) and toxicity (incidence of severe adverse effects (SAEs)) of second-line systemic therapy (single or combined treatment with any anticancer drug, at any dose and number of cycles) in people with metastatic CRC that progressed, recurred or did not respond to first-line systemic therapy.

DATA COLLECTION AND ANALYSIS

Authors performed a descriptive analysis of each included RCT in terms of primary (survival) and secondary (tumour response, toxicity) endpoints. In the light of the variety of drug regimens tested in the included trials, we could carry out meta-analysis considering classes of (rather than single) anticancer regimens; to this aim, we applied the random-effects model to pool the data. We used hazard ratios (HRs) and risk ratios (RRs) to describe the strength of the association for survival (overall (OS) and progression-free survival (PFS)) and dichotomous (overall response rate (ORR) and SAE rate) data, respectively, with 95% confidence intervals (CI).

MAIN RESULTS

Thirty-four RCTs (enrolling 13,787 participants) fulfilled the eligibility criteria. Available evidence enabled us to address multiple clinical issues regarding the survival effects of second-line systemic therapy of people with metastatic CRC.1. Chemotherapy (irinotecan) was more effective than best supportive care (HR for OS: 0.58, 95% CI 0.43 to 0.80; 1 RCT; moderate-quality evidence); 2. modern chemotherapy (FOLFOX (5-fluorouracil plus leucovorin plus oxaliplatin), irinotecan) is more effective than outdated chemotherapy (5-fluorouracil) (HR for PFS: 0.59, 95% CI 0.49 to 0.73; 2 RCTs; high-quality evidence) (HR for OS: 0.69, 95% CI 0.51 to 0.94; 1 RCT; moderate-quality evidence); 3. irinotecan-based combinations were more effective than irinotecan alone (HR for PFS: 0.68, 95% CI 0.60 to 0.76; 6 RCTs; moderate-quality evidence); 4. targeted agents improved the efficacy of conventional chemotherapy both when considered together (HR for OS: 0.84, 95% CI 0.77 to 0.91; 6 RCTs; high-quality evidence) and when bevacizumab was used alone (HR for PFS: 0.67, 95% CI 0.60 to 0.75; 4 RCTs; high-quality evidence).With regard to secondary endpoints, tumour response rates generally paralleled the survival results; moreover, higher anticancer efficacy was generally associated with worse treatment-related toxicity, with the important exception of bevacizumab-containing regimens, where the addition of the targeted agent to chemotherapy did not result in a significant increase in the rate of SAE. Finally, we found that oral (instead of intravenous) fluoropyrimidines significantly reduced the incidence of adverse effects (without compromising efficacy) in people treated with oxaliplatin-based regimens.We could not draw any conclusions on other debated aspects in this field of oncology, such as ranking of treatments (not all possible comparisons have been tested and many comparisons were based on single trials enrolling a small number of participants) and quality of life (virtually no data available).

AUTHORS' CONCLUSIONS

Systemic therapy offers a survival benefit to people with metastatic CRC who did not respond to first-line treatment, especially when targeted agents are combined with conventional chemotherapeutic drugs. Further research is needed to define the optimal regimen and to identify people who most benefit from each treatment.

Dietary fibre for the prevention of recurrent colorectal adenomas and carcinomas

BACKGROUND

This is an update of the Cochrane review published in 2002.Colorectal cancer (CRC) is a major cause of morbidity and mortality in industrialised countries. Experimental evidence has supported the hypothesis that dietary fibre may protect against the development of CRC, although epidemiologic data have been inconclusive.

OBJECTIVES

To assess the effect of dietary fibre on the recurrence of colorectal adenomatous polyps in people with a known history of adenomatous polyps and on the incidence of CRC compared to placebo. Further, to identify the reported incidence of adverse effects, such as abdominal pain or diarrhoea, that resulted from the fibre intervention.

SEARCH METHODS

We identified randomised controlled trials (RCTs) from Cochrane Colorectal Cancer's Specialised Register, CENTRAL, MEDLINE and Embase (search date, 4 April 2016). We also searched ClinicalTrials.gov and WHO International Trials Registry Platform on October 2016.

SELECTION CRITERIA

We included RCTs or quasi-RCTs. The population were those having a history of adenomatous polyps, but no previous history of CRC, and repeated visualisation of the colon/rectum after at least two-years' follow-up. Dietary fibre was the intervention. The primary outcomes were the number of participants with: 1. at least one adenoma, 2. more than one adenoma, 3. at least one adenoma greater than or equal to 1 cm, or 4. a new diagnosis of CRC. The secondary outcome was the number of adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data, assessed trial quality and resolved discrepancies by consensus. We used risk ratios (RR) and risk difference (RD) with 95% confidence intervals (CI) to measure the effect. If statistical significance was reached, we reported the number needed to treat for an additional beneficial outcome (NNTB) or harmful outcome (NNTH). We combined the study data using the fixed-effect model if it was clinically, methodologically, and statistically reasonable.

MAIN RESULTS

We included seven studies, of which five studies with 4798 participants provided data for analyses in this review. The mean ages of the participants ranged from 56 to 66 years. All participants had a history of adenomas, which had been removed to achieve a polyp-free colon at baseline. The interventions were wheat bran fibre, ispaghula husk, or a comprehensive dietary intervention with high fibre whole food sources alone or in combination. The comparators were low-fibre (2 to 3 g per day), placebo, or a regular diet. The combined data showed no statistically significant difference between the intervention and control groups for the number of participants with at least one adenoma (5 RCTs, n = 3641, RR 1.04, 95% CI 0.95 to 1.13, low-quality evidence), more than one adenoma (2 RCTs, n = 2542, RR 1.06, 95% CI 0.94 to 1.20, low-quality evidence), or at least one adenoma 1 cm or greater (4 RCTs, n = 3224, RR 0.99, 95% CI 0.82 to 1.20, low-quality evidence) at three to four years. The results on the number of participants diagnosed with colorectal cancer favoured the control group over the dietary fibre group (2 RCTS, n = 2794, RR 2.70, 95% CI 1.07 to 6.85, low-quality evidence). After 8 years of comprehensive dietary intervention, no statistically significant difference was found in the number of participants with at least one recurrent adenoma (1 RCT, n = 1905, RR 0.97, 95% CI 0.78 to 1.20), or with more than one adenoma (1 RCT, n = 1905, RR 0.89, 95% CI 0.64 to 1.24). More participants given ispaghula husk group had at least one recurrent adenoma than the control group (1 RCT, n = 376, RR 1.45, 95% CI 1.01 to 2.08). Other analyses by types of fibre intervention were not statistically significant. The overall dropout rate was over 16% in these trials with no reasons given for these losses. Sensitivity analysis incorporating these missing data shows that none of the results can be considered as robust; when the large numbers of participants lost to follow-up were assumed to have had an event or not, the results changed sufficiently to alter the conclusions that we would draw. Therefore, the reliability of the findings may have been compromised by these missing data (attrition bias) and should be interpreted with caution.

AUTHORS' CONCLUSIONS

There is a lack of evidence from existing RCTs to suggest that increased dietary fibre intake will reduce the recurrence of adenomatous polyps in those with a history of adenomatous polyps within a two to eight year period. However, these results may be unreliable and should be interpreted cautiously, not only because of the high rate of loss to follow-up, but also because adenomatous polyp is a surrogate outcome for the unobserved true endpoint CRC. Longer-term trials with higher dietary fibre levels are needed to enable confident conclusion.

Heated insufflation with or without humidification for laparoscopic abdominal surgery

BACKGROUND

Intraoperative hypothermia during both open and laparoscopic abdominal surgery may be associated with adverse events. For laparoscopic abdominal surgery, the use of heated insufflation systems for establishing pneumoperitoneum has been described to prevent hypothermia. Humidification of the insufflated gas is also possible. Past studies on heated insufflation have shown inconclusive results with regards to maintenance of core temperature and reduction of postoperative pain and recovery times.

OBJECTIVES

To determine the effect of heated gas insufflation compared to cold gas insufflation on maintaining intraoperative normothermia as well as patient outcomes following laparoscopic abdominal surgery.

SEARCH METHODS

We searched Cochrane Colorectal Cancer Specialised Register (September 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2016, Issue 8), Ovid MEDLINE (1950 to September 2016), Ovid Embase (1974 to September 2016), International Pharmaceutical Abstracts (IPA) (September 2016), Web of Science (1985 to September 2016), Scopus, www.clinicaltrials.gov and the National Research Register (1956 to September 2016). We also searched grey literature and cross references. Searches were limited to human studies without language restriction.

SELECTION CRITERIA

Only randomised controlled trials comparing heated (with or without humidification) with cold gas insufflation in adult and paediatric populations undergoing laparoscopic abdominal procedures were included. We assessed study quality in regards to relevance, design, sequence generation, allocation concealment, blinding, possibility of incomplete data and selective reporting. Two review authors independently selected studies for the review, with any disagreement resolved in consensus with a third co-author.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed screening of eligible studies, data extraction and methodological quality assessment of the trials. We classified a study as low-risk of bias if all of the first six main criteria indicated in the 'Risk of Bias Assessment' table were assessed as low risk. We used data sheets to collect data from eligible studies. We presented results using mean differences for continuous outcomes and relative risks for dichotomous outcomes, with 95% confidence intervals. We used Review Manager (RevMan) 5.3 software to calculate the estimated effects. We took publication bias into consideration and compiled funnel plots.

MAIN RESULTS

We included 22 studies in this updated analysis, including six new trials with 584 additional participants, resulting in a total of 1428 participants. The risk of bias was low in 11 studies, high in one study and unclear in the remaining studies, due primarily to failure to report methodology for randomisation, and allocation concealment or blinding, or both. Fourteen studies examined intraoperative core temperatures among heated and humidified insufflation cohorts and core temperatures were higher compared to cold gas insufflation (MD 0.31 °C, 95% CI, 0.09 to 0.53, I² = 88%, P = 0.005) (low-quality evidence). If the analysis was limited to the eight studies at low risk of bias, this result became non-significant but remained heterogeneous (MD 0.18 °C, 95% CI, -0.04 to 0.39, I²= 81%, P = 0.10) (moderate-quality evidence).In comparison to the cold CO₂ group, the meta-analysis of the heated, non-humidified group also showed no statistically significant difference between groups. Core temperature was statistically, significantly higher in the heated, humidified CO₂ with external warming groups (MD 0.29 °C, 95% CI, 0.05 to 0.52, I² = 84%, P = 0.02) (moderate-quality evidence). Despite the small difference in temperature of 0.31 °C with heated CO₂, this is unlikely to be of clinical significance.For postoperative pain scores, there were no statistically significant differences between heated and cold CO₂, either overall, or for any of the subgroups assessed. Interestingly, morphine-equivalent use was homogeneous and higher in heated, non-humidified insufflation compared to cold insufflation for postoperative day one (MD 11.93 mg, 95% CI 0.92 to 22.94, I² = 0%, P = 0.03) (low-quality evidence) and day two (MD 9.79 mg, 95% CI 1.58 to 18.00, I² = 0%, P = 0.02) (low-quality evidence). However, morphine use was not significantly different six hours postoperatively or in any humidified insufflation groups.There was no apparent effect on length of hospitalisation, lens fogging or length of operation with heated compared to cold gas insufflation, with or without humidification. Recovery room time was shorter in the heated cohort (MD -26.79 minutes, 95% CI -51.34 to -2.25, I² = 95%, P = 0.03) (low-quality evidence). When the one and only unclear-risk study was removed from the analysis, the difference in recovery-room time became non-significant and the studies were statistically homogeneous (MD -1.22 minutes, 95% CI, -6.62 to 4.17, I² = 12%, P = 0.66) (moderate-quality evidence).There were also no differences in the frequency of major adverse events that occurred in the cold or heated cohorts.These results should be interpreted with caution due to some limitations. Heterogeneity of core temperature remained significant despite subgroup analysis, likely due to variations in the study design of the individual trials, as the trials had variations in insufflation gas temperatures (35 ºC to 37 ºC), humidity ranges (88% to 100%), gas volumes and location of the temperature probes. Additionally, some of the trials lacked specific study design information making evaluation difficult.

AUTHORS' CONCLUSIONS

While heated, humidified gas leads to mildly smaller decreases in core body temperatures, clinically this does not account for improved patient outcomes, therefore, there is no clear evidence for the use of heated gas insufflation, with or without humidification, compared to cold gas insufflation in laparoscopic abdominal surgery.

Chromoscopy versus conventional endoscopy for the detection of polyps in the colon and rectum

BACKGROUND

Although conventional colonoscopy is the most accurate test available for the investigation of the colorectum for polyps, data exist that raise concerns about its sensitivity. Chromoscopy (spraying dye onto the surface of the colon to make polyps more visible) may be one way of enhancing the ability of colonoscopy to detect polyps, particularly diminutive flat lesions, which otherwise may be difficult to detect.

OBJECTIVES

To determine whether the use of chromoscopy enhances the detection of polyps and neoplasia during endoscopic examination of the colon and rectum.

SEARCH METHODS

We searched the following databases: Cochrane Colorectal Cancer Group Specialised Register (October 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library; Issue 10, 2015), MEDLINE (January 1950 to October 2015), EMBASE (January 1974 to October 2015), and ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (both November 2015). We also handsearched abstracts from relevant meetings from 1980 to 2015. Search terms included 'randomised trials' containing combinations of the following: 'chromoscopy' 'colonoscopy' 'dye-spray' 'chromo-endoscopy' 'indigo-carmine' 'magnifying endoscopy'.

SELECTION CRITERIA

We included all prospective randomised trials comparing chromoscopic with conventional endoscopic examination of the whole of the colon and rectum. We excluded studies of people with inflammatory bowel disease or polyposis syndromes and any studies that combined chromoscopy with additional interventions (cap assistance, water-perfused, etc.).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the methodological quality of potentially eligible trials, and two review authors independently extracted data from the included trials. Outcome measures included the detection of polyps (neoplastic and non-neoplastic), the detection of diminutive lesions, the number of participants with multiple neoplastic lesions, and the extubation time.

MAIN RESULTS

We included seven trials (2727 participants) in this update. Five trials were of sufficiently similar design to allow for pooled results. Two trials differed substantially in design and were included in a subgroup analysis. All the trials had some methodological drawbacks. However, combining the results showed a significant difference in favour of chromoscopy for all detection outcomes. In particular, chromoscopy was likely to yield significantly more people with at least one neoplastic lesion (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.31 to 1.79; 7 trials; 2727 participants), and at least one diminutive neoplastic lesion (OR 1.51, 95% CI 1.19 to 1.92; 4 trials; 1757 participants). Significantly more people with three or more neoplastic lesions were also detected, but only when studies that used high-definition colonoscopy in the control group were excluded (OR 4.63, 95% CI 1.99 to 10.80; 2 trials; 519 participants). None of the included studies reported any adverse events related to the use of the contrast dye.

AUTHORS' CONCLUSIONS

There is strong evidence that chromoscopy enhances the detection of neoplasia in the colon and rectum. People with neoplastic polyps, particularly those with multiple polyps, are at increased risk of developing colorectal cancer. Such lesions, which presumably would be missed with conventional colonoscopy, could contribute to the interval cancer numbers on any surveillance programme.

Irinotecan chemotherapy combined with fluoropyrimidines versus irinotecan alone for overall survival and progression-free survival in patients with advanced and/or metastatic colorectal cancer

BACKGROUND

Chemotherapy is the treatment of choice in patients with advanced or metastatic colorectal cancer (CRC) where surgical resection of metastases is not an option. Both irinotecan (IRI) and fluoropyrimidines are often included in first- or second- line chemotherapy treatment regimens in such patients. However, it is not clear whether combining these agents is superior to irinotecan alone.

OBJECTIVES

To compare the efficacy and safety of two chemotherapeutic regimens, irinotecan monotherapy or irinotecan in combination with fluoropyrimidines, for patients with advanced CRC when administered in the first or second-line settings.

SEARCH METHODS

We searched the following electronic databases to identify randomized controlled trials: Cochrane Colorectal Cancer Group Specialised Register (January 13, 2016), Cochrane Central Register of Controlled Trials (CENTRAL)(The Cochrane Library Issue 12, 2016), Ovid MEDLINE (1950 to January 13, 2016), Ovid EMBASE (1974 to January 13, 2016), registers of controlled trials in progress, references cited in relevant publications and conference proceedings in related fields (BioMed Central and Medscape's Conference). The key authors or investigators of all eligible studies, and professionals in the field were contacted when necessary. The search from January 2016 identified one eligible study, an ongoing trial currently presented as an abstract, to be considered in an update of this review.

SELECTION CRITERIA

Randomized controlled trials (RCTs) investigating the efficacy and safety of IRI chemotherapy combined with fluoropyrimidine compared with IRI alone for the treatment of patients with advanced CRC, regardless of treatment line settings.

DATA COLLECTION AND ANALYSIS

Study eligibility and methodological quality were assessed independently by the two authors, and any disagreement was solved by a third author. The data collected from the studies were reviewed qualitatively and quantitatively using the Cochrane Collaboration statistical software RevMan 5.3.

MAIN RESULTS

Five studies were included in this review with a total of 1,726 patients. The top-up search resulted in an additional ongoing trial, the results of which have not been incorporated in this review. Among five included studies, no reduction in all-cause mortality was observed in the combination arm, with a summary hazard ratio (HR) of 0.91 (95% CI: 0.81-1.02). Longer progression-free survival was observed in those treated with the combination chemotherapy (HR: 0.68, 95% CI: 0.53-0.87), however, this result may have been driven by findings from the single first-line treatment setting study.The quality of evidence for overall survival was low and for progression-free survival was moderate, mainly due to study limitation from the lack of information on randomisation methods and allocation concealment.There were higher risks of toxicity outcomes grade 3 or 4 diarrhoea and grade 1 or 2 alopecia, and a lower risk of grade 3 or 4 neutropenia in controls compared to the invervention group. Evidence for toxicity has been assessed to be low to moderate quality.

AUTHORS' CONCLUSIONS

There was no overall survival benefit of the irinotecan and fluoropyrimidine treatment over irinotecan alone, thus both regimens remain reasonable options in treating patients with advanced or metastatic CRC. Given the low and moderate quality of the evidence, future studies with sufficient numbers of patients in each treatment arms are needed to clarify the benefit observed in progression-free survival with combination irinotecan and fluoropyrimidines.

Blood CEA levels for detecting recurrent colorectal cancer

BACKGROUND

Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation.

OBJECTIVES

To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice.

SEARCH METHODS

We conducted all searches to January 29 2014. We applied no language limits to the searches, and translated non-English manuscripts. We searched for relevant reviews in the MEDLINE, EMBASE, MEDION and DARE databases. We searched for primary studies (including conference abstracts) in the Cochrane Central Register of Controlled Trials (CENTRAL), in MEDLINE, EMBASE, and the Science Citation Index & Conference Proceedings Citation Index - Science. We identified ongoing studies by searching WHO ICTRP and the ASCO meeting library.

SELECTION CRITERIA

We included cross-sectional diagnostic test accuracy studies, cohort studies, and randomised controlled trials (RCTs) of post-resection colorectal cancer follow-up that compared CEA to a reference standard. We included studies only if we could extract 2 x 2 accuracy data. We excluded case-control studies, as the ratio of cases to controls is determined by the study design, making the data unsuitable for assessing test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors (BDN, IP) assessed the quality of all articles independently, discussing any disagreements. Where we could not reach consensus, a third author (BS) acted as moderator. We assessed methodological quality against QUADAS-2 criteria. We extracted binary diagnostic accuracy data from all included studies as 2 x 2 tables. We conducted a bivariate meta-analysis. We used the xtmelogit command in Stata to produce the pooled estimates of sensitivity and specificity and we also produced hierarchical summary ROC plots.

MAIN RESULTS

In the 52 included studies, sensitivity ranged from 41% to 97% and specificity from 52% to 100%. In the seven studies reporting the impact of applying a threshold of 2.5 µg/L, pooled sensitivity was 82% (95% confidence interval (CI) 78% to 86%) and pooled specificity 80% (95% CI 59% to 92%). In the 23 studies reporting the impact of applying a threshold of 5 µg/L, pooled sensitivity was 71% (95% CI 64% to 76%) and pooled specificity 88% (95% CI 84% to 92%). In the seven studies reporting the impact of applying a threshold of 10 µg/L, pooled sensitivity was 68% (95% CI 53% to 79%) and pooled specificity 97% (95% CI 90% to 99%).

AUTHORS' CONCLUSIONS

CEA is insufficiently sensitive to be used alone, even with a low threshold. It is therefore essential to augment CEA monitoring with another diagnostic modality in order to avoid missed cases. Trying to improve sensitivity by adopting a low threshold is a poor strategy because of the high numbers of false alarms generated. We therefore recommend monitoring for colorectal cancer recurrence with more than one diagnostic modality but applying the highest CEA cut-off assessed (10 µg/L).

Combination chemotherapy versus single-agent chemotherapy during preoperative chemoradiation for resectable rectal cancer

BACKGROUND

Colorectal cancer represents 10% of all cancers and is the third most common cause of death in women and men. Almost two-thirds of all bowel cancers are cancers of the colon and over one-third (34%) are cancers of the rectum, including the anus. Surgery is the cornerstone for curative treatment of rectal cancer. Mesorectal excision decreases the rate of local recurrences; however, it does not improve the overall survival of people with locally advanced rectal cancer. There have been significant research efforts since the mid-1990s to optimise the treatment of rectal cancer. Based on the findings of clinical trials, people with T3/T4 or N+ rectal tumours are now being treated preoperatively with radiation and chemotherapy, mainly fluoropyrimidine. However, the incidence of distant metastases remains as high as 30%. Combination chemotherapy regimens, similar to those used in metastatic disease with the addition of oxaliplatin and irinotecan, have been tested to improve the prognosis of people with rectal cancer.

OBJECTIVES

To compare outcomes (including overall survival, disease-free survival and toxicity) between two 5-fluorouracil-containing chemotherapy regimens in people with stage II and III rectal cancer who are receiving preoperative chemoradiation.

SEARCH METHODS

We searched the Cochrane Colorectal Cancer Group Specialised Register (January 2015), the Cochrane Central Register of Controlled Trials (2015, Issue 1), Ovid MEDLINE (1950 to January 2015), Ovid EMBASE (1974 to January 2015) and LILACS (1982 to January 2015). We reviewed the reference lists of included studies, checked clinical trials registers and handsearched relevant journal proceedings. We applied no language or publication restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing single-agent chemotherapy (fluoropyrimidine) versus combination chemotherapy (fluoropyrimidine plus another agent including, but not limited to, oxaliplatin) during preoperative radiochemotherapy in people with resectable rectal cancer.

DATA COLLECTION AND ANALYSIS

Two review authors (HMR, EMKS) independently extracted data and assessed trial quality. When necessary, we requested additional information and clarification of published data from the authors of individual trials.

MAIN RESULTS

We included four RCTs involving 3875 people with resectable rectal cancer. In the preoperative period, the participants of these studies were randomised to receive chemoradiation either with a single fluoropyrimidine agent (capecitabine or 5-fluorouracil) or with a combination of drugs (fluoropyrimidine plus oxaliplatin). The only study that reported overall survival and disease-free survival found no significant differences between the intervention and control groups; we considered this evidence very low quality. For pathological complete response after preoperative treatment (ypCR) there was high quality evidence favouring the intervention group (odds ratio (OR) 1.23, 95% confidence interval (CI) 1.04 to 1.46), but there was also moderate quality evidence suggesting a higher risk for early toxicity in the intervention group (OR 2.07, 95% CI 1.31 to 3.27). Moderate to high quality evidence suggested that the control group had better compliance to radiotherapy (OR 0.32, 95% CI 0.14 to 0.75). There were no significant differences between groups in postoperative mortality within 60 days, postoperative morbidity, resection margins, abdominoperineal resection and Hartmann procedures.

AUTHORS' CONCLUSIONS

There was very low quality evidence that people with resectable rectal cancer who receive combination preoperative chemotherapy have no improvements in overall survival or disease-free survival. There was high quality evidence that suggested that combination chemotherapy with oxaliplatin may improve local tumour control in people with resectable rectal cancer, but this regimen also caused more toxicity. The review included four RCTs but only one reported survival; therefore, we cannot make robust conclusions or useful clinical recommendations. The publication of more survival data from these studies will contribute to future analyses.

Antimicrobial prophylaxis for colorectal surgery

BACKGROUND

Research shows that administration of prophylactic antibiotics before colorectal surgery prevents postoperative surgical wound infection. The best antibiotic choice, timing of administration and route of administration remain undetermined.

OBJECTIVES

To establish the effectiveness of antimicrobial prophylaxis for the prevention of surgical wound infection in patients undergoing colorectal surgery. Specifically to determine:1. whether antimicrobial prophylaxis reduces the risk of surgical wound infection;2. the target spectrum of bacteria (aerobic or anaerobic bacteria, or both);3. the best timing and duration of antibiotic administration;4. the most effective route of antibiotic administration (intravenous, oral or both);5. whether any antibiotic is clearly more effective than the currently recommended gold standard specified in published guidelines;6. whether antibiotics should be given before or after surgery.

SEARCH METHODS

For the original review published in 2009 we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid). For the update of this review we rewrote the search strategies and extended the search to cover from 1954 for MEDLINE and 1974 for EMBASE up to 7 January 2013. We searched CENTRAL on the same date (Issue 12, 2012).

SELECTION CRITERIA

Randomised controlled trials of prophylactic antibiotic use in elective and emergency colorectal surgery, with surgical wound infection as an outcome.

DATA COLLECTION AND ANALYSIS

Data were abstracted and reviewed by one review author and checked by another only for the single, dichotomous outcome of surgical wound infection. Quality of evidence was assessed using GRADE methods.

MAIN RESULTS

This updated review includes 260 trials and 68 different antibiotics, including 24 cephalosporins and 43,451 participants. Many studies had multiple variables that separated the two study groups; these could not be compared to other studies that tested one antibiotic and had a single variable separating the two groups. We did not consider the risk of bias arising from attrition and lack of blinding of outcome assessors to affect the results for surgical wound infection.Meta-analyses demonstrated a statistically significant difference in postoperative surgical wound infection when prophylactic antibiotics were compared to placebo/no treatment (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.28 to 0.41, high quality evidence). This translates to a reduction in risk from 39% to 13% with prophylactic antibiotics. The slightly higher risk of wound infection with short-term compared with long-term duration antibiotic did not reach statistical significance (RR 1.10, 95% CI 0.93 to 1.30). Similarly risk of would infection was slightly higher with single-dose antibiotics when compared with multiple dose antibiotics, but the results are compatible with benefit and harm (RR 1.30, 95% CI 0.81 to 2.10). Additional aerobic coverage and additional anaerobic coverage both showed statistically significant improvements in surgical wound infection rates (RR 0.44, 95% CI 0.29 to 0.68 and RR 0.47, 95% CI 0.31 to 0.71, respectively), as did combined oral and intravenous antibiotic prophylaxis when compared to intravenous alone (RR 0.56, 95% CI 0.43 to 0.74), or oral alone (RR 0.56, 95% CI 0.40 to 0.76). Comparison of an antibiotic with anaerobic specificity to one with aerobic specificity showed no significant advantage for either one (RR 0.84, 95% CI 0.30 to 2.36). Two small studies compared giving antibiotics before or after surgery and no significant difference in this timing was found (RR 0.67, 95% CI 0.21 to 2.15). Established gold-standard regimens recommended in major guidelines were no less effective than any other antibiotic choice.

AUTHORS' CONCLUSIONS

This review has found high quality evidence that antibiotics covering aerobic and anaerobic bacteria delivered orally or intravenously (or both) prior to elective colorectal surgery reduce the risk of surgical wound infection. Our review shows that antibiotics delivered within this framework can reduce the risk of postoperative surgical wound infection by as much as 75%. It is not known whether oral antibiotics would still have these effects when the colon is not empty. This aspect of antibiotic dosing has not been tested. Further research is required to establish the optimal timing and duration of dosing, and the frequency of longer-term adverse effects such as Clostridium difficile pseudomembranous colitis.

Laparoscopic versus open total mesorectal excision for rectal cancer

BACKGROUND

Colorectal cancer including rectal cancer is the third most common cause of cancer deaths in the western world. For colon carcinoma, laparoscopic surgery is proven to result in faster postoperative recovery, fewer complications and better cosmetic results with equal oncologic results. These short-term benefits are expected to be similar for laparoscopic rectal cancer surgery. However, the oncological safety of laparoscopic surgery for rectal cancer remained controversial due to the lack of definitive long-term results. Thus, the expected short-term benefits can only be of interest when oncological results are at least equal.

OBJECTIVES

To evaluate the differences in short- and long-term results after elective laparoscopic total mesorectal excision (LTME) for the resection of rectal cancer compared with open total mesorectal excision (OTME).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2013, Issue 2), MEDLINE (January 1990 to February 2013), EMBASE (January 1990 to February 2013), ClinicalTrials.gov (February 2013) and Current Controlled Trials (February 2013). We handsearched the reference lists of the included articles for missed studies.

SELECTION CRITERIA

Only randomised controlled trials (RCTs) comparing LTME and OTME, reporting at least one of our outcome measures, was considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality according to the CONSORT statement, and resolved disagreements by discussion. We rated the quality of the evidence using GRADE methods.

MAIN RESULTS

We identified 45 references out of 953 search results, of which 14 studies met the inclusion criteria involving 3528 rectal cancer patients. We did not consider the risk of bias of the included studies to have impacted on the quality of the evidence. Data were analysed according to an intention-to-treat principle with a mean conversion rate of 14.5% (range 0% to 35%) in the laparoscopic group.There was moderate quality evidence that laparoscopic and open TME had similar effects on five-year disease-free survival (OR 1.02; 95% CI 0.76 to1.38, 4 studies, N = 943). The estimated effects of laparoscopic and open TME on local recurrence and overall survival were similar, although confidence intervals were wide, both with moderate quality evidence (local recurrence: OR 0.89; 95% CI 0.57 to1.39 and overall survival rate: OR 1.15; 95% CI 0.87 to1.52). There was moderate to high quality evidence that the number of resected lymph nodes and surgical margins were similar between the two groups.For the short-term results, length of hospital stay was reduced by two days (95% CI -3.22 to -1.10), moderate quality evidence), and the time to first defecation was shorter in the LTME group (-0.86 days; 95% CI -1.17 to -0.54). There was moderate quality evidence that 30 days morbidity were similar in both groups (OR 0.94; 95% CI 0.8 to 1.1). There were fewer wound infections (OR 0.68; 95% CI 0.50 to 0.93) and fewer bleeding complications (OR 0.30; 95% CI 0.10 to 0.93) in the LTME group.There was no clear evidence of any differences in quality of life after LTME or OTME regarding functional recovery, bladder and sexual function. The costs were higher for LTME with differences up to GBP 2000 for direct costs only.

AUTHORS' CONCLUSIONS

We have found moderate quality evidence that laparoscopic total mesorectal excision (TME) has similar effects to open TME on long term survival outcomes for the treatment of rectal cancer. The quality of the evidence was downgraded due to imprecision and further research could impact on our confidence in this result. There is moderate quality evidence that it leads to better short-term post-surgical outcomes in terms of recovery for non-locally advanced rectal cancer. Currently results are consistent in showing a similar disease-free survival and overall survival, and for recurrences after at least three years and up to 10 years, although due to imprecision we cannot rule out superiority of either approach. We await long-term data from a number of ongoing and recently completed studies to contribute to a more robust analysis of long-term disease free, overall survival and local recurrence.

Flexible sigmoidoscopy versus faecal occult blood testing for colorectal cancer screening in asymptomatic individuals

BACKGROUND

Colorectal cancer is the third most frequent cancer in the world. As the sojourn time for this cancer is several years and a good prognosis is associated with early stage diagnosis, screening has been implemented in a number of countries. Both screening with faecal occult blood test and flexible sigmoidoscopy have been shown to reduce mortality from colorectal cancer in randomised controlled trials. The comparative effectiveness of these tests on colorectal cancer mortality has, however, never been evaluated, and controversies exist over which test to choose.

OBJECTIVES

To compare the effectiveness of screening for colorectal cancer with flexible sigmoidoscopy to faecal occult blood testing.

SEARCH METHODS

We searched MEDLINE and EMBASE (November 16, 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 11) and reference lists for eligible studies.

SELECTION CRITERIA

Randomised controlled trials comparing screening with flexible sigmoidoscopy or faecal occult blood testing to each other or to no screening. Only studies reporting mortality from colorectal cancer were included. Faecal occult blood testing had to be repeated (annually or biennially).

DATA COLLECTION AND ANALYSIS

Data retrieval and assessment of risk of bias were performed independently by two review authors. Standard meta-analyses using a random-effects model were conducted for flexible sigmoidoscopy and faecal occult blood testing (FOBT) separately and we calculated relative risks with 95% confidence intervals (CI). We used a Bayesian approach (a contrast-based network meta-analysis method) for indirect analyses and presented the results as posterior median relative risk with 95% credibility intervals. We assessed the quality of evidence using GRADE.

MAIN RESULTS

We identified nine studies comprising 338,467 individuals randomised to screening and 405,919 individuals to the control groups. Five studies compared flexible sigmoidoscopy to no screening and four studies compared repetitive guaiac-based FOBT (annually and biennially) to no screening. We did not consider that study risk of bias reduced our confidence in our results. We did not identify any studies comparing the two screening methods directly. When compared with no screening, colorectal cancer mortality was lower with flexible sigmoidoscopy (relative risk 0.72; 95% CI 0.65 to 0.79, high quality evidence) and FOBT (relative risk 0.86; 95% CI 0.80 to 0.92, high quality evidence). In the analyses based on indirect comparison of the two screening methods, the relative risk of dying from colorectal cancer was 0.85 (95% credibility interval 0.72 to 1.01, low quality evidence) for flexible sigmoidoscopy screening compared to FOBT. No complications occurred after the FOBT test itself, but 0.03% of participants suffered a major complication after follow-up. Among more than 60,000 flexible sigmoidoscopy screening procedures and almost 6000 work-up colonoscopies, a major complication was recorded in 0.08% of participants. Adverse event data should be interpreted with caution as the reporting of adverse effects was incomplete.

AUTHORS' CONCLUSIONS

There is high quality evidence that both flexible sigmoidoscopy and faecal occult blood testing reduce colorectal cancer mortality when applied as screening tools. There is low quality indirect evidence that screening with either approach reduces colorectal cancer deaths more than the other. Major complications associated with screening require validation from studies with more complete reporting of harms

WITHDRAWN: Herbal medicines for advanced colorectal cancer

The review is withdrawn due to its insufficient quality.

The editorial group responsible for this previously published document have withdrawn it from publication.

Mechanical bowel preparation for elective colorectal surgery

BACKGROUND

The presence of bowel contents during colorectal surgery has been related to anastomotic leakage, but the belief that mechanical bowel preparation (MBP) is an efficient agent against leakage and infectious complications is based on observational data and expert opinions only.An enema before the rectal surgery to clean the rectum and facilitate the manipulation for the mechanical anastomosis is used for many surgeons. This is analysed separately

OBJECTIVES

To determine the security and effectiveness of MBP on morbidity and mortality in colorectal surgery.

SEARCH STRATEGY

Publications describing trials of MBP before elective colorectal surgery were sought through searches of MEDLINE, EMBASE, LILACS, IBECS and The Cochrane Library; by handsearching relevant medical journals and conference proceedings, and through personal communication with colleagues.Searches were performed December 1, 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including participants submitted for elective colorectal surgery. Eligible interventions included any type of MBP compared with no MBP. Primary outcomes included anastomosis leakage - both rectal and colonic - and combined figures. Secondary outcomes included mortality, peritonitis, reoperation, wound infection, extra-abdominal complications, and overall surgical site infections.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and checked. The methodological quality of each trial was assessed. Details of randomisation, blinding, type of analysis, and number lost to follow up were recorded. For analysis, the Peto-Odds Ratio (OR) was used as the default (no statistical heterogeneity was observed).

MAIN RESULTS

At this update six trials and a new comparison (Mechanical bowel preparation versus enema) were added. Altogether eighteen trials were analysed, with 5805 participants; 2906 allocated to MBP (Group A), and 2899 to no preparation (Group B), before elective colorectal surgery.For the comparison Mechanical Bowel Preparation Versus No Mechanical Bowel Preparation results were:1. Anastomotic leakage for low anterior resection: 8.8% (38/431) of Group A, compared with 10.3% (43/415) of Group B; Peto OR 0.88 [0.55, 1.40].2. Anastomotic leakage for colonic surgery: 3.0% (47/1559) of Group A, compared with 3.5% (56/1588) of Group B; Peto OR 0.85 [0.58, 1.26].3. Overall anastomotic leakage: 4.4% (101/2275) of Group A, compared with 4.5% (103/2258) of Group B; Peto OR 0.99 [0.74, 1.31].4. Wound infection: 9.6% (223/2305) of Group A, compared with 8.5% (196/2290) of Group B; Peto OR 1.16 [0.95, 1.42].Sensitivity analyses did not produce any differences in overall results.For the comparison Mechanical Bowel Preparation (A) Versus Rectal Enema (B) results were:1. Anastomotic leakage after rectal surgery: 7.4% (8/107) of Group A, compared with 7.9% (7/88) of Group B; Peto OR 0.93 [0.34, 2.52].2. Anastomotic leakage after colonic surgery: 4.0% (11/269) of Group A, compared with 2.0% (6/299) of Group B; Peto OR 2.15 [0.79, 5.84].3. Overall anastomotic leakage: 4.4% (27/601) of Group A, compared with 3.4% (21/609) of Group B; Peto OR 1.32 [0.74, 2.36].4. Wound infection: 9.9% (60/601) of Group A, compared with 8.0% (49/609) of Group B; Peto OR 1.26 [0.85, 1.88].

AUTHORS' CONCLUSIONS

Despite the inclusion of more studies with a total of 5805 participants, there is no statistically significant evidence that patients benefit from mechanical bowel preparation, nor the use of rectal enemas. In colonic surgery the bowel cleansing can be safely omitted and induces no lower complication rate. The few studies focused in rectal surgery suggested that mechanical bowel preparation could be used selectively, even though no significant effect was found. Further research on patients submitted for elective rectal surgery, below the peritoneal verge, in whom bowel continuity is restored, and studies with patients submitted to laparoscopic surgeries are still warranted.

Laparoscopic versus open surgery in small bowel obstruction

BACKGROUND

Acute intestinal obstruction is one of the most common surgical emergencies. The small bowel obstruction (SBO) is the site of obstruction in most patients (76%) and adhesions are the most common etiology (65%). Laparoscopy in SBO has no clear role yet as it may have a therapeutic and diagnostic function. In some settings laparoscopic or laparoscopy-assisted surgery is considered feasible and convenient more than conventional surgery for SBO; however little is known if laparoscopic or laparoscopy-assisted surgery is more suitable with respect to open surgery for patients with SBO.

OBJECTIVES

The aim of this systematic review is to assess whether laparoscopic or laparoscopy-assisted surgery is feasible and safe for acute SBO, and whether laparoscopic and laparoscopy-assisted surgery present advantages compared to open surgery in terms of short-term and long-term outcomes.

SEARCH STRATEGY

We searched for published randomised and prospective controlled clinical trials without language restrictions using the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1950 onwards) and EMBASE (1980 onwards).

SELECTION CRITERIA

Randomised controlled trials and non randomised controlled prospective trials evaluating laparoscopic and laparoscopy-assisted surgery versus traditional open surgery for acute SBO were considered.

DATA COLLECTION AND ANALYSIS

We conducted the review according to the recommendations of The Cochrane Collaboration and the Cochrane Colorectal Group as well, using Review Manager 5 to conduct the review.

MAIN RESULTS

No published or unpublished randomised controlled trials or prospective controlled clinical trials comparing laparoscopy with open surgery for patients with SBO were identified.

AUTHORS' CONCLUSIONS

Although data from retrospective clinical controlled trials suggest that laparoscopy seems feasible and better in terms of hospital stay and mortality reduction, high quality randomised controlled trials assessing all clinically relevant outcomes including overall mortality, morbidity, hospital stay and conversion are needed.

Cesarean delivery for the prevention of anal incontinence

BACKGROUND

Caesarean delivery (CD) is a common form of delivery of a baby, rising in frequency. One reason for its performance is to preserve maternal pelvic floor function, part of which is anal continence.

OBJECTIVES

To assess the ability of CD in comparison to vaginal delivery (VD) to preserve anal continence in a systematic review

SEARCH STRATEGY

Search terms include: "Caesarean section, Cesarean delivery, vaginal delivery, incontinence and randomised". PubMed, EMBASE and the Cochrane Central Register of Controlled Trials (Central) were searched from their inception through July, 2009.

SELECTION CRITERIA

Both randomised and non-randomised studies that allowed comparisons of post partum anal continence (both fecal and flatus) in women who had had babies delivered by either CD or VD were included.

DATA COLLECTION AND ANALYSIS

Mode of delivery, and when possible mode of all previous deliveries prior to the index pregnancy were extracted, as well as assessment of continence post partum of both faeces and flatus. In Non-RCTs, available adjusted odds ratios were the primary end point sought. Incontinence of flatus is reported as a separate outcome. Summary odds ratios are not presented as no study was analysed as a randomised controlled trial. Numbers needed to treat (NNT) are presented, that is, the number of CDs needed to be performed to prevent a single case of fecal or flatus incontinence, for each individual study. Quality criteria were developed, selecting studies that allowed maternal age adjustment, studies that allowed a sufficient time after the birth of the baby for continence assessment and studies in which mode of delivery of prior pregnancies was known. Subgroup analyses were done selecting studies meeting all quality criteria and in comparisons of elective versus emergency CD, elective CD versus VD and nulliparous women versus those delivered by VD or CD, in each case again, not calculating a summary risk statistic.

MAIN RESULTS

Twentyone reports have been found eligible for inclusion in the review, encompassing 31,698 women having had 6,028 CDs and 25,170 VDs as the index event prior to anal continence assessment . Only one report randomised women (with breech presentation) to CD or VD, but because of extensive crossing over, 52.1%, after randomisation, it was analysed along with the other 20 studies as treated, i.e. as a non-randomised trial. Only one of these reports demonstrated a significant benefit of CD in the preservation of anal continence, a report in which incontinence incidence was extremely high, 39% in CD and 48% in VD, questioning, relative to other reports, the timing and nature of continence assessment. The greater the quality of the report, the closer its Odds ratio approached 1.0. There was no difference in continence preservation in women have emergency versus elective CD.

AUTHORS' CONCLUSIONS

Without demonstrable benefit, preservation of anal continence should not be used as a criterion for choosing elective primary CD. The strength of this conclusion would be greatly strengthened if there were studies that randomised women with average risk pregnancies to CD versus VD.

Duration of adjuvant chemotherapy for patients with non-metastatic colorectal cancer

BACKGROUND

Surgery of primary tumour is the backbone of colorectal cancer treatment (CRC). But in stage III cancer, metastatic or local relapse is often observed (50%). So, adjuvant treatment is always considered in this setting. The best treatment duration of hypothetic disease is not easy to define. Adjuvant chemotherapy for CRC actually lasts 6 months. The choice of optimal duration is based upon old studies using 5-fluorouracil (5FU). During the last ten years, results of major randomized controlled studies (RCTs) comparing different durations of treatments and different schedules in adjuvant setting were published. Several studies compared a 6-month chemotherapy with a longer treatment. Conversely, a single study by Chau et al compared a 6 month chemotherapy with continuous treatment lasting 3 months. But the optimal duration of these chemotherapies could be challenged. Even though the optimal duration of chemotherapy in CRC is a major issue, it has never been answered adequately.

OBJECTIVES

To evaluate the optimal duration of adjuvant treatment, we performed a meta-analysis of all RCTs comparing two durations of adjuvant treatment, 6 months versus 9 to 12 months.

SEARCH STRATEGY

Publications were identified from PubMed (February 28th, 2009), Embase, and the Cochrane Database of Clinical Controlled Trials (CENTRAL) in the Cochrane Library 2009 issue 1. Reviews and books were also scrutinized. Abstracts were reviewed from ASCO annual meetings proceedings from 1998 to 2009.

SELECTION CRITERIA

Patients with surgically resected colorectal cancer with high risk of recurrence.

DATA COLLECTION AND ANALYSIS

Several RCTs compared shorter versus longer durations of chemotherapy, 6 studies for overall survival (OS) and 7 studies for relapse free survival (RFS), for a total of 10326 patients, mean age 63.1 years, including 9826 colon and 500 rectum cancers.

MAIN RESULTS

Treatments were always based on 5-FU. Two studies were excluded, an epidemiological study and a study comparing continuous treatment during 3 months with conventional chemotherapy during 6 months. The later because it compared 2 durations less than or equal to 6 months. Shorter duration of chemotherapy (3-6 months) compared with longer duration (9-12 months) was not associated to poorer RFS (RR =0.96, 95% CI : 0.90-1.02) and OS (RR = 0.96 ; 95% CI : 0.91-1.02).

AUTHORS' CONCLUSIONS

The present meta-analysis confirmed that adjuvant chemotherapy of CRC should not last for more than 6 months. Prolonged duration would result in lower benefit to risk ratio. However, the results do not make it possible to favour either 3 or 6 month durations. They should help design a future RCT comparing different durations of continuous treatment.

Selective internal radiation therapy for liver metastases from colorectal cancer

BACKGROUND

Liver metastases are often the dominant site of metastatic disease in colorectal cancer. Selective internal radiation therapy (SIRT) involves embolising radiolabeled spheres (SIR-Spheres) into the arterial supply of the liver with the aim of improving the control of liver metastases.

OBJECTIVES

To assess the effectiveness and toxicity of SIRT in the treatment of metastatic colorectal cancer liver metastasis when given alone or with systemic or regional hepatic artery chemotherapy.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane library 2008 issue 2, MEDLINE (1966 to October 2008), EMBASE (1980 to October 2008), and Pubmed (October 2008). The proceedings of ASCO (1985 to 2008) and ASCO GI (2004 to 2008) were also searched. The manufacturers of SIR-Spheres were contacted and asked whether they were aware of any other unpublished studies.

SELECTION CRITERIA

Randomised controlled trials comparing SIRT and chemotherapy (systemic and/or regional) with chemotherapy alone, or comparing SIRT alone with best supportive care in patients with metastatic colorectal cancer.

DATA COLLECTION AND ANALYSIS

Two authors (AT/TP) extracted data and assessed the trial quality. The study authors were contacted and individual patient data was obtained. Results were analysed separately for patients with and without extra-hepatic disease.

MAIN RESULTS

A single study of 21 patients compared SIRT and systemic chemotherapy (fluorouracil and leucovorin) with chemotherapy alone. There was a significant improvement in progression free survival and median survival associated with SIRT, both for the total studied population and for those disease limited to the liver. There was an increase in toxicity with the use of SIRT. A second study of 63 eligible patients compared SIRT and regional chemotherapy (floxuridine) with regional chemotherapy alone. There was no significant difference in progression free survival and median survival seen with SIRT, in either the total patient group or in the 22 patients with disease limited to the liver. There was no significant increase in toxicity with the addition of SIRT to regional chemotherapy. There were no randomised studies comparing SIRT with best supportive care in patients with refractory disease, and no randomised studies assessing the effect of SIRT in patients with resectable liver metastases.

AUTHORS' CONCLUSIONS

There is a need for well designed, adequately powered phase III trials assessing the effect of SIRT when used with modern combination chemotherapy regimens. Further studies are also needed for patients with refractory disease with a particular focus on the impact on quality of life.

Open surgical procedures for incisional hernias

BACKGROUND

Incisional hernias occur frequently after abdominal surgery and can cause serious complications. The choice of a type of open operative repair is controversial. Determining the type of open operative repair is controversial, as the recurrence rate may be as high as 54%.

OBJECTIVES

To identify the best available open operative techniques for incisional hernias.

SEARCH STRATEGY

Electronic databases MEDLINE, EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 1990 to 2007 and trials were identified from the known trial reference lists.

SELECTION CRITERIA

Studies were eligible for inclusion if they were randomized trials comparing different techniques for open operative techniques for incisional hernias.

DATA COLLECTION AND ANALYSIS

Statistical analyses were performed using the fixed effects model. Results were expressed as relative risk for dichotomous outcomes and weighted mean difference for continuous outcomes with 95% confidence intervals.

MAIN RESULTS

Eight trials comparing different open repairs for incisional hernias were identified; one trial was excluded. The included studies enrolled 1,141 patients. The results of three trials comparing suture repair versus mesh repair were pooled. Hernia recurrence was more frequent, wound infection less frequent in the direct suture group compared to the onlay or sublay mesh groups. The recurrence rates of two trials comparing onlay and sublay positions were pooled. This comparison yielded no difference in recurrences (two studies pooled), although operation time was shorter in the onlay group (one study). No difference was found in recurrence, satisfaction with cosmetics, or infection between the onlay standard mesh and skin autograft groups, following analysis pooling the two treatment arms. However, the analysis demonstrated less pain in the skin autograft group. Other trials comparing different mesh materials or different positions of the mesh, or comparing mesh with the components separation technique are described individually. The comparison between lightweight and standard mesh showed a trend for more recurrences in the lightweight group. The comparison between onlay and intraperitoneal mesh positions resulted in non significant fewer hernia recurrences, less seroma formation and more postoperative pain in the intraperitoneal group. No differences in the recurrence rates between the components separation and the intraperitoneal mesh technique.

AUTHORS' CONCLUSIONS

There is good evidence from three trials that open mesh repair is superior to suture repair in terms of recurrences, but inferior when considering wound infection. Six trials yielded insufficient evidence as to which type of mesh or which mesh position (on- or sublay) should be used. There was also insufficient evidence to advocate the use of the components separation technique.

Ileostomy or colostomy for temporary decompression of colorectal anastomosis

BACKGROUND

The use of loop ileostomy or loop transverse colostomy represents an important issue in colorectal surgery. Despite a slight preference for a loop ileostomy as a temporary stoma, the best form for temporary decompression of colorectal anastomosis still remains controversial.

OBJECTIVES

To assess the evidence in the use of loop ileostomy compared with loop transverse colostomy for temporary decompression of colorectal anastomosis, comparing the safety and effectiveness.

SEARCH STRATEGY

We identified randomised controlled trials from MEDLINE, EMBASE, Lilacs, and the Cochrane Central Register of Controlled Trials. Further, by hand-searching relevant medical journals and proceedings from major gastroenterological congresses. We did not limit the seaches regarding date and language.

SELECTION CRITERIA

We assessed all randomised clinical trials, that met the objectives and reported major outcomes: 1. Mortality; 2. Wound infection; 3. Time of formation of stoma; 4. Time of closure of stoma; 5. Time interval between formation and closure of stoma; 6. Stoma prolapse; 7. Stoma retraction; 8. Parastomal hernia; 9. Parastomal fistula; 10. Stenosis; 11. Necrosis; 12. Skin irritation; 13. Ileus; 14. Bowel leakage; 15. Reoperation; 16. Patient adaptation; 17. Length of hospital stay; 18. Colorectal anastomotic dehiscence; 19. Incisional hernia; 20. Postoperative bowel obstruction.

DATA COLLECTION AND ANALYSIS

Details of the randomisation, blinding, whether an intention-to-treat analysis was done, and the number of patients lost to follow-up was recorded. For data analysis the relative risk and risk difference were used with corresponding 95% confidence interval; fixed effect was used for all outcomes unless incisional hernia (random effect model). Statistical heterogeneity in the results of the meta-analysis was assessed by inspection of graphical presentation (funnel plot) and by calculating a test of heterogeneity.

MAIN RESULTS

Five trials were included with 334 patients: 168 to loop ileostomy group and 166 to loop transverse colostomy group. The continuous outcomes could not be measured because of the lack of the data. The outcomes stoma prolapse had statistical significant difference: p=0.00001, but with statistical heterogeneity, p=0,001. When the sensitive analysis was applied excluding the trials that included emergencies surgeries, the result had a discreet difference: p = 0.02 and Test for heterogeneity: chi-square = 0.78, df = 2, p = 0.68, I(2)=0%.

AUTHORS' CONCLUSIONS

The best available evidence for decompression of colorectal anastomosis, either use of loop ileostomy or loop colostomy, could not be clarified from this review. So far, the results in terms of occurrence of postoperative stoma prolapse support the choice of loop ileostomy as a technique for fecal diversion for colorectal anastomosis, but large scale RCT's is needed to verify this.

Transabdominal pre-peritoneal (TAPP) vs totally extraperitoneal (TEP) laparoscopic techniques for inguinal hernia repair

BACKGROUND

The choice of approach to the laparoscopic repair of inguinal hernia is controversial. There is a scarcity of data comparing the laparoscopic transabdominal preperitoneal (TAPP) approach with the laparoscopic totally extraperitoneal (TEP) approach and questions remain about their relative merits and risks.

OBJECTIVES

To compare the clinical effectiveness and relative efficiency of laparoscopic TAPP and laparoscopic TEP for inguinal hernia repair.

SEARCH STRATEGY

We searched Medline Extra, Embase, Biosis, Science Citation Index, Cochrane Central Register of Controlled Trials (CENTRAL), Journals@ Ovid Full Text and the electronic version of the journal, Surgical Endoscopy. Recent conference proceedings by the following organisations were hand searched: Association of Endoscopic Surgeons of Great Britain & Ireland; International Congress of the European Association for Endoscopic Surgery; Scientific Session of the Society of American Gastrointestinal & Endoscopic Surgeons (SAGES); and the Italian Society of Endoscopic Surgery. In addition, specialists involved in research on the repair of inguinal hernia were contacted to ask for information about any further completed and ongoing trials, relevant websites were searched and reference lists of the all included studies were checked for additional reports.

SELECTION CRITERIA

All published and unpublished randomised controlled trials and quasi-randomised controlled trials comparing laparoscopic TAPP with laparoscopic TEP for inguinal hernia repair were eligible for inclusion. Non-randomised prospective studies were also eligible for inclusion to provide further comparative evidence of complications and adverse events.

DATA COLLECTION AND ANALYSIS

Statistical analyses were performed using the fixed effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

The search identified one RCT which reported no statistical difference between TAPP and TEP when considering duration of operation, haematoma, length of stay, time to return to usual activity and recurrence. The eight non-randomised studies suggest that TAPP is associated with higher rates of port-site hernias and visceral injuries whilst there appear to be more conversions with TEP. Vascular injuries and deep/mesh infections were rare and there was no obvious difference between the groups. No studies reporting economic evidence were identified. Very limited data were available on learning effects but these data suggest that operators become experienced at between 30 and 100 procedures.

AUTHORS' CONCLUSIONS

There is insufficient data to allow conclusions to be drawn about the relative effectiveness of TEP compared with TAPP. Efforts should be made to start and complete adequately powered RCTs, which compare the different methods of laparoscopic repair.

Prophylactic anastomotic drainage for colorectal surgery

BACKGROUND

There is little agreement on prophylactic use of drains in anastomoses in elective colorectal surgery despite many randomized clinical trials. Results of these trials are contradictory, quality and statistical power of these individual studies have been questioned. Once anastomotic leakage has occurred it is generally agreed that drains should be used for therapeutic purposes. However, on prophylactic use no such agreement exists.

OBJECTIVES

Comparison of safety and effectiveness of routine drainage and non-drainage regimes after colorectal surgery. The following hypothesis was tested: The use of prophylactic anastomotic drainage after elective colorectal surgery does not prevent development of complications.

SEARCH STRATEGY

The studies were identified from CINAHL, EMBASE, LILACS, MEDLINE, Controlled Clinical Trials Database, Trials Register of the Cochrane Colorectal Cancer Group, reference lists.

SELECTION CRITERIA

Randomized controlled trials comparing drainage with non-drainage regimes after anastomoses in elective colorectal surgery were reviewed. Outcome measures were: 1. mortality; 2. clinical anastomotic dehiscence; 3. radiological anastomotic dehiscence; 4. wound infection; 5. reoperation; 6. extra-abdominal complications.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and cross-checked by the two reviewers. The methodological quality of each trial was assessed. Details of the randomization (generation and concealment), blinding, and the number of patients lost to follow-up were recorded. The RCTs were stratified based on experimental group, according to clinical homogeneity (external validity).

MAIN RESULTS

Of the 1140 patients enrolled (6 RCTs), 573 were allocated for drainage and 567 for no drainage. The patients assigned to the drainage group compared with the ones assigned to non-drainage group showed: a) Mortality: 3% (18 of 573 patients) compared with 4% (25 of 567 patients); b) Clinical anastomotic dehiscence: 2% (11 of 522 patients) compared with 1% (7 of 519 patients); c) Radiological anastomotic dehiscence: 3% (16 of 522 patients) compared with 4% (19 of 519 patients); d) Wound infection: 5% (29 of 573 patients) compared with 5% (28 of 567 patients); e) Reintervention: 6% (34 of 542 patients) compared with 5% (28 of 539 patients); f) Extra abdominal complications: 7% (34 of 522 patients) compared with 6% (32 of 519 patients).

REVIEWERS' CONCLUSIONS

There is insufficient evidence showing that routine drainage after colorectal anastomoses prevents anastomotic and other complications.

Curative surgery for obstruction from primary left colorectal carcinoma: primary or staged resection?

BACKGROUND

In 8 to 29% of patients with colorectal carcinoma, obstruction is the main symptom at diagnosis, and 85% of patients undergoing emergency colorectal surgery have obstruction from colorectal carcinoma. The prognosis of patients who undergo emergency surgery for obstruction is often poor. So far, two types of surgical approach have been used for this condition: primary resection (primary anastomosis or Hartmann's procedure) with simultaneous treatment of carcinoma and obstruction, or staged resection (treatment of the obstruction prior to resection).However, neither strategy has been found to have any advantages over the other.

OBJECTIVES

To ascertain whether primary resection in patients with obstruction from left colorectal carcinoma has advantages over staged resection in terms of morbidity and mortality.

SEARCH STRATEGY

Electronic database searches of Cochrane Controlled Trials Register, Medline, Cancerlit, Embase. Hand searching of the most important journals in the fields of oncology and surgery from 2003 and onward until the time of writing.

SELECTION CRITERIA

Randomised Clinical Trials (RCT) and Controlled Clinical Trials (CCT), in which a group of patients who undergo primary resection for intestinal obstruction from left primary colorectal carcinoma is compared with a group of patients who undergo staged resection for the same condition. Since only one study of this type was available, we considered all other studies, except for case-controls, on the basis of the best possible available evidence. Studies were considered without language restrictions.

DATA COLLECTION AND ANALYSIS

Two reviewers (GLDS, CG) examined all the citations and abstracts derived from the electronic search strategy. Reports of potentially relevant trials were retrieved in full. Both reviewers independently applied the selection criteria to trials reports. Reviewers were not blind to the names of institutions, journals or authors of trials. A third opinion (SP, ML) was obtained to resolve disagreements.

MAIN RESULTS

We identified 2043 citations: Medline 1205, Embase 635, Cancerlit 203. One study for potential inclusion was identified, but was then excluded (Kronborg 1995).

REVIEWERS' CONCLUSIONS

The limited number of identified trials together with their methodological weaknesses do not allow a reliable assessment of the role of either therapeutic strategy in the treatment of patients with bowel obstruction from colorectal carcinoma. It would appear advisable to conduct high quality large scale RCT to establish which treatment is more effective. However, it is doubtful whether they could be carried out in a timely and satisfactory way in this particular surgical context.

Palliative chemotherapy for advanced or metastatic colorectal cancer. Colorectal Meta-analysis Collaboration

BACKGROUND

Despite the increasing use of palliative chemotherapy for advanced colorectal cancer, there remains uncertainty as to the true effectiveness of this intervention. This review was therefore undertaken to assess the available evidence for the benefit of palliative chemotherapy in this disease.

OBJECTIVES

To determine the benefits and harms of palliative chemotherapy in patients with locally advanced or metastatic colorectal cancer. A secondary objective was to investigate outcomes for younger and elderly patients.

SEARCH STRATEGY

Trials were identified by computerised and hand searches of the literature, scanning references and contacting investigators.

SELECTION CRITERIA

All randomised controlled trials of palliative chemotherapy compared with supportive care alone in patients with advanced or metastatic colorectal cancer. Both randomised and non-randomised studies were considered when searching for data on quality of life, resource use and cost effectiveness of palliative chemotherapy.

DATA COLLECTION AND ANALYSIS

Investigators from all eligible studies were asked to supply individual patient data. Meta-analysis was performed using both published data and individual patient data. Studies were grouped according to whether chemotherapy was administered regionally or systemically.

MAIN RESULTS

13 randomised controlled trials representing a total of 1365 randomised patients met the inclusion criteria. Meta-analysis of a subset of trials that provided individual patient data demonstrated that palliative chemotherapy was associated with a 35% (95% CI 24% to 44%) reduction in the risk of death. This translates into an absolute improvement in survival of 16% at both 6 months and 12 months and an improvement in median survival of 3.7 months. The overall quality of evidence relating to treatment toxicity, symptom control and quality of life was poor.

REVIEWER'S CONCLUSIONS

Chemotherapy is effective in prolonging time to disease progression and survival in patients with advanced colorectal cancer. The survival benefit may be underestimated by this meta-analysis, as a proportion of patients in the control arms of some trials received chemotherapy. No age related differences were found in the effectiveness of chemotherapy, but elderly patients were under represented in trials. Treatment toxicity and impact upon quality of life and symptom control have been inadequately assessed in the majority of trials and further research is needed to clarify the palliative benefit of chemotherapy.