Clinical trial: the impact of cyclooxygenase inhibitors on gastrointestinal recovery after major surgery - a randomized double blind controlled trial of celecoxib or diclofenac vs. placebo

Alterations of Prostanoid Expression and Intestinal Epithelial Barrier Functions in Ileus

INTRODUCTION

Intestinal manipulation (IM)-induced inflammation could contribute to postoperative ileus (POI) pathophysiology via the modulation of prostanoid pathways. To identify the prostanoids involved, we aimed to characterize the profile of prostanoids and their synthesis enzyme expression in a murine model of POI and to determine whether the altered prostanoids could contribute to POI.

METHODS

Four or 14 h after IM in mice, gastrointestinal (GI) motility and intestinal epithelial barrier (IEB) permeability were assessed in vivo and ex vivo in Ussing chambers. Using high sensitivity liquid chromatography-tandem mass spectrometry, we characterized the tissue profile of polyunsaturated fatty acid metabolites in our experimental model. Finally, we evaluated in vivo the effects of the prostanoids studied upon IM-induced gut dysfunctions.

RESULTS

We first showed that 14 h after IM was significantly faster than jejunal transit at 4 h post-IM, although it remained significantly increased compared to the control. In contrast, we showed that IM-induced inflammation increase in jejunum permeability was similar after four and 14 h. We next showed that expression of prostacyclin synthase and hemopoietic prostaglandin-D synthase mRNA and their products were significantly reduced 14 h after IM as compared to controls. Furthermore, 15-deoxy-delta 12,14-Prostaglandin J2 reduced the IM-induced inflammation increase in IEB permeability but had no effect on GI motility. In contrast, PGI2 increased IM-induced IEB permeability and motility dysfunctions.

CONCLUSIONS

Arachidonic acid derivative contributes differentially to GI dysfunction in POI. The decrease of 15-deoxy-delta 12,14-Prostaglandin J2 levels induced by IM could contribute to impaired GI dysfunctions in POI and could be considered as putative therapeutic targets to restore barrier dysfunctions associated with POI.

Mismatch of populations between randomised controlled trials of perioperative interventions in major abdominal surgery and current clinical practice

BACKGROUND

Demographics of patients undergoing major abdominal surgery are changing. External validity of relevant RCTs may be limited by participants not resembling patients encountered in clinical practice. We aimed to characterise differences in age, weight, BMI, and ASA grade between participants in perioperative trials in major abdominal surgery and patients in a reference real-world clinical practice sample. The secondary aim was to investigate whether time since trial publication was associated with increasing mismatch between these groups.

METHODS

MEDLINE and Embase were searched for multicentre RCTs from inception to September 2022. Studies of perioperative interventions in adults were included. Studies that limited enrolment based on age, weight, BMI, or ASA status were excluded. We compared trial cohort age, weight, BMI, and ASA distribution to those of patients undergoing major abdominal surgery at our tertiary referral hospital during September 2021 to September 2022. We used a local, single-institution reference sample to reflect the reality of clinical practice (i.e. patients treated by a clinician in their own hospital, rather than averaged nationally). Mismatch was defined using comparison of summary characteristics and ad hoc criteria based on differences relevant to predicted mortality risk after surgery.

RESULTS

One-hundred and six trials (44,499 participants) were compared to a reference cohort of 2792 clinical practice patients. Trials were published a median (IQR [range]) 13.4 (5-20 [0-35]) years ago. A total of 94.3% of trials were mismatched on at least one characteristic (age, weight, BMI, ASA). Recruitment of ASA 3 + participants in trials increased over time, and recruitment of ASA 1 participants decreased over time (Spearman's Rho 0.58 and - 0.44, respectively).

CONCLUSIONS

Patients encountered in our current local clinical practice are significantly different from those in our defined set of perioperative RCTs. Older trials recruit more low-risk than high-risk participants-trials may thus 'expire' over time. These trials may not be generalisable to current patients undergoing major abdominal surgery, and meta-analyses or guidelines incorporating these trials may therefore be similarly non-applicable. Comparison to local, rather than national cohorts, is important for meaningful on-the-ground evidence-based decision-making.

Postoperative Ileus: a Pharmacological Perspective

Post-operative ileus (POI) is a frequent complication after abdominal surgery. The consequences of POI can be potentially serious such as bronchial inhalation or acute functional renal failure. Numerous advances in peri-operative management, particularly early rehabilitation, have made it possible to decrease POI. Despite this, the rate of prolonged POI ileus remains high and can be as high as 25% of patients in colorectal surgery. From a pathophysiological point of view, POI has two phases, an early neurological phase and a later inflammatory phase, to which we could add a "pharmacological" phase during which analgesic drugs, particularly opiates, play a central role. The aim of this review article is to describe the phases of the pathophysiology of POI, to analyse the pharmacological treatments currently available through published clinical trials and finally to discuss the different research areas for potential pharmacological targets.

Targeting Mechano-Transcription Process as Therapeutic Intervention in Gastrointestinal Disorders

Mechano-transcription is a process whereby mechanical stress alters gene expression. The gastrointestinal (GI) tract is composed of a series of hollow organs, often encountered by transient or persistent mechanical stress. Recent studies have revealed that persistent mechanical stress is present in obstructive, functional, and inflammatory disorders and alters gene transcription in these conditions. Mechano-transcription of inflammatory molecules, pain mediators, pro-fibrotic and growth factors has been shown to play a key role in the development of motility dysfunction, visceral hypersensitivity, inflammation, and fibrosis in the gut. In particular, mechanical stress-induced cyclooxygenase-2 (COX-2) and certain pro-inflammatory mediators in gut smooth muscle cells are responsible for motility dysfunction and inflammatory process. Mechano-transcription of pain mediators such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) may lead to visceral hypersensitivity. Emerging evidence suggests that mechanical stress in the gut also leads to up-regulation of certain proliferative and pro-fibrotic mediators such as connective tissue growth factor (CTGF) and osteopontin (OPN), which may contribute to fibrostenotic Crohn's disease. In this review, we will discuss the pathophysiological significance of mechanical stress-induced expression of pro-inflammatory molecules, pain mediators, pro-fibrotic and growth factors in obstructive, inflammatory, and functional bowel disorders. We will also evaluate potential therapeutic targets of mechano-transcription process for the management of these disorders.

Non-steroidal anti-inflammatory agents and anastomotic leak rates across colorectal cancer operations and anastomotic sites: A systematic review and meta-analysis of anastomosis specific leak rate and confounding factors

BACKGROUND

Surgical intervention presents a fundamental therapeutic choice in the management of colorectal malignancies. Complications, the most serious one being anastomotic leak (AL), still have detrimental effects upon patients' morbidity and mortality. We aimed to assess whether NSAIDs, and their sub-categories, increase AL in colonic anastomoses and to identify whether this affects specific anastomotic sites.

MATERIALS AND METHODS

A systematic search of MEDLINE, Cochrane Library, ClinicalTrials.gov, Web of Science, Science Direct, Google Scholar was conducted between January 1, 1999 till the October 30, 2020. Cohort studies and randomized control trials examining AL events in NSAID-exposed, colorectal cancer patients were included. NSAIDs were grouped according to the 2019 NICE guidelines in non-specific (NS-NSAIDs) and specific COX-2 inhibitors. The primary outcome was AL events in NSAID-exposed patients undergoing operations with either ileocolic, colocolic or colorectal anastomoses. Secondary outcomes included NSAID category-specific AL events and demographic confounding factors increasing AL risk in this patient population.

RESULTS

Fifteen studies involving 25,395 patients were included in the systematic review and meta-analysis. Of all anastomoses, colocolic anastomoses were found to be statistically more prone to AL events in the NS-NSAID-exposed population [OR 3.24 (95% CI 0.98-10.72), p = 0.054]. Male gender was an independent confounder increasing AL rate regardless of NSAID exposure.

CONCLUSION

The association between NSAID exposure and AL in oncology patients remains undetermined. Whilst in present work, colocolic anastomoses appear to be more sensitive to AL events, the observed association may be anastomotic site and NSAID-category dependent.

Postoperative ileus-An ongoing conundrum

BACKGROUND

Postoperative ileus is common and is a major clinical problem. It has been widely studied in patients and in experimental models in laboratory animals. A wide variety of treatments have been tested to prevent or modify the course of this disorder.

PURPOSE

This review draws together information on animal studies of ileus with studies on human patients. It summarizes some of the conceptual advances made in understanding the mechanisms that underlie paralytic ileus. The treatments that have been tested in human subjects (both pharmacological and non-pharmacological) and their efficacy are summarized and graded consistent with current clinical guidelines. The review is not intended to provide a comprehensive overview of ileus, but rather a general understanding of the major clinical problems associated with it, how animal models have been useful to elucidate key mechanisms and, finally, some perspectives from both scientists and clinicians as to how we may move forward with this debilitating yet common condition.

Multimodal perioperative pain protocol for gynecologic laparotomy is associated with reduced hospital length of stay

OBJECTIVES

The primary objective was to evaluate the impact of a multimodal perioperative pain regimen on length of hospital stay for patients undergoing laparotomy with a gynecologic oncologist.

METHODS

We compared 52 patients who underwent laparotomy with a gynecologic oncologist at a single institution between 2017 and 2018, after implementation of a multimodal perioperative pain regimen, to a historic cohort of 94 patients (2016-2017). The multimodal pain regimen included pre- and post-operative administration of oral acetaminophen, gabapentin, and celecoxib, in addition to standard narcotics and optional epidural analgesia. Demographic, surgical, and post-operative data were collected.

RESULTS

On multivariable analysis, bowel resection, stage, surgery length, age, and cohort group were retained as significant independent predictors of length of stay. Patients undergoing laparotomy prior to the pain protocol had a length of stay 1.26 times longer than patients during the post-implementation period (p < 0.01). For complex surgical patients, this translated into a reduction in length of hospital stay of 1.73 days. There was a significant reduction in pain scale score on post-operative day zero from 5 to 3 (p = 0.02) and a non-significant overall reduction of post-operative morphine equivalents, with similar adverse outcomes.

CONCLUSION

Implementation of a multimodal perioperative pain regimen in patients undergoing gynecologic oncology laparotomy was associated with a significant reduction of length of hospital stay and improved patient-perceived pain, even in the absence of a complete Enhanced Recovery After Surgery (ERAS) protocol.

State-of-the-art colorectal disease: postoperative ileus

PURPOSE

Postoperative Ileus (POI) remains an important complication for patients after abdominal surgery with an incidence of 10-27% representing an everyday issue for abdominal surgeons. It accounts for patients' discomfort, increased morbidity, prolonged hospital stays, and a high economic burden. This review outlines the current understanding of POI pathophysiology and focuses on preventive treatments that have proven to be effective or at least show promising effects.

METHODS

Pathophysiology and recommendations for POI treatment are summarized on the basis of a selective literature review.

RESULTS

While a lot of therapies have been researched over the past decades, many of them failed to prove successful in meta-analyses. To date, there is no evidence-based treatment once POI has manifested. In the era of enhanced recovery after surgery or fast track regimes, a few approaches show a beneficial effect in preventing POI: multimodal, opioid-sparing analgesia with placement of epidural catheters or transverse abdominis plane block; μ-opioid-receptor antagonists; and goal-directed fluid therapy and in general the use of minimally invasive surgery.

CONCLUSION

The results of different studies are often contradictory, as a concise definition of POI and reliable surrogate endpoints are still absent. These will be needed to advance POI research and provide clinicians with consistent data to improve the treatment strategies.

Perioperative Nonsteroidal Anti-inflammatory Drugs (NSAID) Administration and Acute Kidney Injury (AKI) in Major Gastrointestinal Surgery: A Prospective, Multicenter, Propensity Matched Cohort Study

OBJECTIVE

This study aimed to determine the relationship between early postoperative nonsteroidal anti-inflammatory drug (NSAID) administration and postoperative acute kidney injury (AKI) and anastomotic leak.

SUMMARY BACKGROUND DATA

NSAIDs have analgesic, opioid-sparing, and anti-inflammatory effects. However, their postoperative use is limited by concerns around increased risk of AKI and anastomotic leak.

METHODS

A secondary analysis of a multicenter, prospective cohort study including patients undergoing elective or emergency major gastrointestinal surgery from September to December 2015 across 173 hospitals in the United Kingdom and Ireland. Exposure to early postoperative NSAIDs was defined as NSAID administration on postoperative days 0 to 3. The primary outcome was the 7-day postoperative AKI rate. Propensity score matching was used to balance treatment groups and estimate treatment effects that are presented as odds ratios, alongside the corresponding 95% confidence interval (CI).

RESULTS

Overall 19.8% (1039/5240) of patients received early NSAIDs. AKI rates were 10.6% in the early NSAID group and 14.9% in the no NSAID group. The anastomotic leak rate in patients who received an anastomosis was 4.8% in the NSAIDs group and 6.0% in the no NSAIDs group. Following propensity score matching, early use of NSAIDs was not significantly associated with AKI (adjusted odds ratio 0.80, 95% CI 0.63-1.00, P = 0.057). This finding was consistent in subgroup analyses by NSAID dosage and timing. In patients who had a gastrointestinal anastomosis, NSAIDs were not associated with anastomotic leak (adjusted odds ratio 0.85, 95% CI 0.58-1.21, P = 0.382).

CONCLUSIONS

Administration of NSAIDs in the early postoperative period is safe in selected patients following major gastrointestinal surgery.

Postoperative administration of non-steroidal anti-inflammatory drugs in colorectal cancer surgery does not increase anastomotic leak rate; A systematic review and meta-analysis

BACKGROUND

Evidence on the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on anastomotic leak (AL) rate after colorectal surgery is conflicting. Effects of NSAIDs might depend on the underlying disease. This meta-analysis aimed to review the effect of NSAIDs on AL rate in a homogeneous colorectal cancer patient population.

METHODS

A systematic literature search using MEDLINE and EMBASE database was performed for studies with AL as primary outcome comparing NSAID use in the early postoperative phase with no NSAID administration in colorectal cancer patients undergoing surgical resection.

RESULTS

Nine studies including 10,868 patients met the inclusion criteria. The majority, 7689 patients (70.7%) underwent low anterior resection and 3050 patients (28.1%) underwent colonic resection. The pooled incidence of AL was 8.6% (95%CI 7.0-10.0). Overall AL rate after colorectal cancer surgery was not increased in patients using NSAIDs for postoperative analgesia compared to non-users (p = 0.34, RR 1.23; 95%CI 0.81-1.86). This effect remained non-significant after stratification for low anterior resections (p = 0.07). Stratification for colonic resections could not be performed because AL results for this subgroup were not reported separately. Neither non-selective NSAID use nor COX-2 selective NSAID use caused an increased AL rate (p = 0.19, p = 0.26). The results were robust throughout sensitivity analyses.

CONCLUSION

Use of NSAIDs in cohorts with patients undergoing surgical resection for colorectal cancer does not increase overall AL rate. Since results were robust throughout several subgroup and sensitivity analyses, prescription of NSAIDs after colorectal cancer surgery seems safe.

The Impact of Nonsteroidal Anti-inflammatory Drugs on Older Adult Trauma Patients With Hip Fractures

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) use is frequently recommended for multimodal analgesia to reduce opioid use. We hypothesized that increased NSAID utilization will decrease opioid requirements without leading to significant complications in older adult trauma patients undergoing hip fracture repair.

METHODS

An observational cross-sectional cohort study of 190,057 adult trauma patients over a 6-y period (2008-2014) in the national Premier Healthcare Database was performed. Patients aged 65 or older undergoing femur repair and hip arthroplasty following fractures due to falls were analyzed. Primary outcome was opioid use, and secondary outcomes included transfusion requirements, length of stay (LOS), and organ system dysfunction. Continuous outcomes were analyzed using mixed-effect linear regression models to assess the effect of NSAIDs on the day of surgery. Fixed effects were included for patient and hospital characteristics, comorbidities, co-treatments, and surgery. Random intercepts for each hospital were included to control for clustering. Categorical outcomes were similarly analyzed using mixed-effect logistic regression models.

RESULTS

NSAIDs decreased opioids prescribed (12.01 versus 11.43 morphine milligram equivalents) (odds ratio [OR], -0.23; confidence interval [CI] = -0.41, -0.06) without overall increased bleeding (40.83% versus 43.18%; OR, 1.02; CI = 0.99, 1.05). NSAIDs were associated with reduced LOS (5.61 versus 5.96 d; CI = -0.24, -0.12), intensive care unit admissions (9.73% versus 10.59%; OR, 0.91; CI = 0.86, 0.96), and pulmonary complications (OR, 0.88; CI = 0.83, 0.93). Additionally, there was a 21% prescribing variability based solely on hospital.

CONCLUSIONS

NSAIDs were associated with decreased opioid requirements, hospital LOS, and intensive care unit admissions in older adult trauma patients without overall increase in bleeding. NSAIDs should be considered in multimodal pain regimens, moreover, given prescribing variability guidelines are needed.

LEVEL OF EVIDENCE

Level III, Prognostic.

Postoperative non-steroidal anti-inflammatory drugs and anastomotic leakage after gastrointestinal anastomoses: Systematic review and meta-analysis

AIM

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to control postoperative pain; however, their postoperative use has been associated with anastomotic leakage after gastrointestinal surgery. This systematic review and meta-analysis aimed to determine the correlation between the use of NSAIDs and anastomotic leakage.

METHODS

We conducted a comprehensive electronic literature search up to August 2018 to identify studies comparing anastomotic leakage in patients with and without postoperative NSAID use following gastrointestinal surgery. We then carried out a meta-analysis using random-effects models to calculate odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Twenty-four studies were included in this meta-analysis, including a total of 31 877 patients. Meta-analysis showed a significant association between NSAID use and anastomotic leakage (OR 1.73; 95% CI = 1.31-2.29, P < .0001). Subgroup analyses showed that non-selective NSAIDs, but not selective cyclooxygenase-2 inhibitors, were significantly associated with anastomotic leakage. However there was no significant subgroup difference between selective and non-selective NSAIDs.

CONCLUSION

Results of this meta-analysis indicate that postoperative NSAID use is associated with anastomotic leakage following gastrointestinal surgeries. Caution is warranted when using NSAIDs for postoperative analgesic control in patients with gastrointestinal anastomoses.

Pain Management in Enhanced Recovery after Surgery (ERAS) Protocols

Pain control is an integral part of Enhanced Recovery after Surgery (ERAS) protocols for colorectal surgery. While opioid therapy remains the mainstay of therapy for postsurgical pain, opioids have undesired side effects including delayed recovery of bowel function, respiratory depression, and postoperative nausea and vomiting. A variety of nonopioid systemic medical therapies as well as regional and neuraxial techniques have been described as improving pain control while reducing opioid use. Multimodal and preemptive analgesia as part of an ERAS protocol facilitates early mobility and early return of bowel function and decreases postoperative morbidity. In this review, we examine several multimodal therapies and their impact on postoperative analgesia, opioid use, and recovery for patients undergoing colorectal surgery.

Systematic Review and Meta-analysis of Nonsteroidal Anti-inflammatory Drugs to Improve GI Recovery After Colorectal Surgery

BACKGROUND

The management of delayed GI recovery after surgery is an unmet challenge. Uncertainty over its pathophysiology has limited previous research, but recent evidence identifies intestinal inflammation and activation of µ-opioid receptors as key mechanisms. Nonsteroidal anti-inflammatory drugs are recommended by enhanced recovery protocols for their opioid-sparing and anti-inflammatory properties.

OBJECTIVES

The purpose of this study was to explore the safety and efficacy of nonsteroidal anti-inflammatory drugs to improve GI recovery and to identify opportunities for future research.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Library were systematically searched from inception up to January 2018.

STUDY SELECTION

Randomized controlled trials assessing the effect of nonsteroidal anti-inflammatory drugs on GI recovery after elective colorectal surgery were eligible.

MAIN OUTCOME MEASURES

Postoperative GI recovery, including first passage of flatus, stool, and oral tolerance, were measured.

RESULTS

Six randomized controlled trials involving 563 participants were identified. All of the participants received patient-controlled morphine and either nonsteroidal anti-inflammatory drug (nonselective: n = 4; cyclooxygenase-2 selective: n = 1; either: n = 1) or placebo. Patients receiving the active drug had faster return of flatus (mean difference: -17.73 h (95% CI, -21.26 to -14.19 h); p < 0.001), stool (-9.52 h (95% CI, -14.74 to -4.79 h); p < 0.001), and oral tolerance (-12.00 h (95% CI, -18.01 to -5.99 h); p < 0.001). Morphine consumption was reduced in the active groups of 4 studies (average reduction, 12.9-30.0 mg), and 1 study demonstrated significantly reduced measures of systemic inflammation. Nonsteroidal anti-inflammatory drugs were not associated with adverse events, but 1 study was temporarily suspended for safety.

LIMITATIONS

The data presented are relatively outdated but represent the best available evidence.

CONCLUSIONS

Nonsteroidal anti-inflammatory drugs may represent an effective and accessible intervention to improve GI recovery, but hesitancy over their use after colorectal surgery persists. Additional preclinical research to characterize their mechanisms of action, followed by well-designed clinical studies to test safety and patient-reported efficacy, should be considered.

Anti-inflammatory Effects of Enhanced Recovery Programs on Early-Stage Colorectal Cancer Surgery

BACKGROUND

Postoperative ileus (POI) is observed in 20-30% of patients undergoing colorectal cancer surgery, despite enhanced recovery programs (ERPs). Cyclooxygenase (COX)-2 is identified as a key enzyme in POI, but other arachidonic acid pathway enzymes have received little attention despite their potential as selective targets to prevent POI. The objectives were to compare the expression of arachidonic acid metabolism (AAM) enzymes (1) between patients who underwent colorectal cancer surgery and followed an ERP or not (NERP), (2) and between ERP patients who experimented POI or not and (3) to determine the ability of antagonists of these pathways to modulate contractile activity of colonic muscle.

METHODS

This was a translational study. Main outcome measures were gastrointestinal motility recovery data, mRNA expressions of key enzymes involved in AAM (RT-qPCR) and ex vivo motility values of the circular colon muscle. Twenty-eight prospectively included ERP patients were compared to eleven retrospectively included NERP patients that underwent colorectal cancer surgery.

RESULTS

ERP reduced colonic mucosal COX-2, microsomal prostaglandin E synthase (mPGES1) and hematopoietic prostaglandin D synthase (HPGDS) mRNA expression. mPGES1 and HPGDS mRNA expression were significantly associated with ERP compliance (respectively, r2 = 0.25, p = 0.002 and r2 = 0.6, p < 0.001). In muscularis propria, HPGDS mRNA expression was correlated with GI motility recovery (p = 0.002). The pharmacological inhibition of mPGES1 increased spontaneous ex vivo contractile activity in circular muscle (p = 0.03).

CONCLUSION

The effects of ERP on GI recovery are correlated with the compliance of ERP and could be mediated at least in part by mPGES1, HPGDS and COX-2. Furthermore, mPGES1 shows promise as a therapeutic target to further reduce POI duration among ERP patients.

Nonsteroidal anti-inflammatory drugs reduce the time to recovery of gut function after elective colorectal surgery: a systematic review and meta-analysis

AIM

Postoperative ileus causes significant patient morbidity after abdominal surgery. Some evidence suggests nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce time to gut recovery, but there has not been a meta-analysis to assess their efficacy. This systematic review and meta-analysis aimed to determine the benefit of NSAIDs for recovery of postoperative gut function in patients undergoing elective colorectal surgery.

METHOD

MEDLINE, EMBASE, CENTRAL and reference lists were searched with no date or language restrictions. Randomized controlled trials comparing the use of NSAIDs with placebo in the perioperative or postoperative period were identified. Included studies reported outcomes relevant to gut function: time to pass flatus or stool and time to tolerate an oral diet. The mean difference in time from surgery until passage of flatus, stool and tolerance of diet were meta-analysed using a random-effects model in RevMan 5.3.

RESULTS

This study identified 992 relevant articles. Five randomized controlled trials on patients undergoing elective colorectal surgery met our inclusion criteria and were meta-analysed. Compared with placebo, NSAIDs significantly improved the time to pass flatus (mean difference -9.44 h, 95% CI: -17.22, -1.65, I² = 70%, P = 0.02), time to pass stool (mean difference -12.09 h, 95% CI: -17.16, -7.02, I² = 0%, P < 0.001) and time to tolerate a diet (mean difference -11.95 h, 95% CI: -18.66, -5.24, I² = 0%, P < 0.001).

CONCLUSION

NSAIDs significantly improve time to gut recovery after elective colorectal surgery. Current evidence is not adequate to identify whether selective or nonselective drugs should be recommended. Further high-power studies using selective drugs are required.

Gastrografin may reduce time to oral diet in prolonged post-operative ileus: a pooled analysis of two randomized trials

BACKGROUND

Gastrografin has been suggested as a rescue therapy for prolonged post-operative ileus (PPOI) but trial data has been inconclusive. This study aimed to determine the benefit of gastrografin use in patients with PPOI by pooling the results of two recent randomized controlled trials assessing the efficacy of gastrografin compared to placebo given at time of PPOI diagnosis.

METHODS

Anonymized, individual patient data from patients undergoing elective bowel resection for any indication were included, stoma closure was excluded. The primary outcome was duration of PPOI. Secondary outcomes were time to tolerate oral diet, passage of flatus/stool, requirement and duration of nasogastric tube, length of post-operative stay and rate of post-operative complications.

RESULTS

Individual patient data were pooled for analysis (53 gastrografin, 55 placebo). Gastrografin trended towards a reduction in PPOI duration compared to placebo, respectively, median 96 h (interquartile range, IQR, 78 h) versus median 120 h (IQR, 84 h), however, this result was non-significant (P = 0.11). In addition, no significant difference was detected between the two groups for time to passage of flatus/stool (P = 0.36) and overall length of stay (P = 0.35). Gastrografin conferred a significantly faster time to tolerate an oral diet compared to placebo (median 84 h versus median 107 h, P = 0.04). There was no difference in post-operative complications between the two interventions (P > 0.05).

CONCLUSION

Gastrografin did not significantly reduce PPOI duration or length of stay after abdominal surgery, but did reduce time to tolerate a solid diet. Further studies are required to clarify the role of gastrografin in PPOI.

Postoperative ileus following major colorectal surgery

BACKGROUND

Postoperative ileus (POI) is characterized by delayed gastrointestinal recovery following surgery. Current knowledge of pathophysiology, clinical interventions and methodological challenges was reviewed to inform modern practice and future research.

METHODS

A systematic search of MEDLINE and Embase databases was performed using search terms related to ileus and colorectal surgery. All RCTs involving an intervention to prevent or reduce POI published between 1990 and 2016 were identified. Grey literature, non-full-text manuscripts, and reanalyses of previous RCTs were excluded. Eligible articles were assessed using the Cochrane tool for assessing risk of bias.

RESULTS

Of 5614 studies screened, 86 eligible articles describing 88 RCTs were identified. Current knowledge of pathophysiology acknowledges neurogenic, inflammatory and pharmacological mechanisms, but much of the evidence arises from animal studies. The most common interventions tested were chewing gum (11 trials) and early enteral feeding (11), which are safe but of unclear benefit for actively reducing POI. Others, including thoracic epidural analgesia (8), systemic lidocaine (8) and peripheral μ antagonists (5), show benefit but require further investigation for safety and cost-effectiveness.

CONCLUSION

POI is a common condition with no established definition, aetiology or treatment. According to current literature, minimally invasive surgery, protocol-driven recovery (including early feeding and opioid avoidance strategies) and measures to avoid major inflammatory events (such as anastomotic leak) offer the best chances of reducing POI.

A Comparison of Multimodal Analgesic Approaches in Institutional Enhanced Recovery After Surgery Protocols for Colorectal Surgery: Pharmacological Agents

INTRODUCTION

Enhanced Recovery After Surgery (ERAS^®) protocols are the cornerstone of improved recovery after colorectal surgery. Their implementation leads to reduced morbidity and shorter hospital stays while attenuating the surgical stress response. Multimodal analgesia is an important part of ERAS protocols. We compared and contrasted protocols from 15 institutions to test our hypothesis that there is a fundamental consensus among them.

MATERIALS AND METHODS

ERAS protocols for open and laparoscopic colorectal surgery were compared from 15 different healthcare facilities. We examined each institution's approach to multimodal analgesia related to the use of oral and intravenous analgesics. Preoperative, intraoperative, and postoperative management was examined.

RESULTS

All but three protocols used preoperative multimodal analgesics, with acetaminophen, celecoxib, and gabapentin being the most common. Intraoperative recommendations included the use of ketamine, lidocaine, magnesium, and ketorolac. Some protocols advocated for the use of opiates, while others aimed to minimize total opioid dose. In the postoperative period, the three most utilized agents were acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and opioids.

CONCLUSIONS

There were many similarities and some significant differences among ERAS protocols examined. Acetaminophen was the most widely used nonopioid agent and along with NSAIDs offers a benefit with respect to postoperative analgesia, opioid-sparing effects, earlier ambulation, and reduction in postoperative ileus. Gabapentin was widely used as it may reduce opioid consumption within the first 24 hours postoperatively. Lidocaine infusion was recommended if there were contraindications to or failure of epidural anesthesia. Ketamine is frequently recommended due to its analgesic, antihyperalgesic, antiallodynic, and antitolerance properties. Differences in approaches may be due to both institutional- and provider-level factors.

Nomogram-Derived Prediction of Postoperative Ileus after Colectomy: An Assessment from Nationwide Procedure-Targeted Cohort

Postoperative ileus (POI) is a clinical burden to health-care system. This study aims to evaluate the incidence and predictors of POI in patients undergoing colectomy and create a nomogram by using recently released procedure-targeted nationwide database. Patients who underwent elective colectomy in 2012 and 2013 were identified from American College of Surgeons National Surgical Quality Improvement Program using the new procedure-targeted database. Demographics, comorbidities, and 30-day postoperative outcomes were evaluated. Variables in the final step-wise multiple logistic regression model for each outcome were selected in a stepwise fashion using Akaike's information criterion. A nomogram was created to aid in the calculation of POI risk for individual patients. A total of 29,201 patients met the inclusion criteria; 3834 (13.1%) developed POI with a male predominance (55.9%). Patients who developed ileus had longer length of hospital stay (11 vs 5 days; P < 0.001) and operative time (200 vs 174 minutes; P < 0.001). In the stepwise logistic regression model, the following variables were found to be independent risk factors for POI: older age (P < 0.001), male gender (P < 0.001), American Society of Anesthesiologists class III/IV (P < 0.001), open approach (P < 0.001), preoperative septic conditions (P < 0.001), omission of oral antibiotic before surgery (P < 0.001), right colectomy or total colectomy vs other procedures (P < 0.001), smoking (P = 0.001), decreased preoperative serum albumin level (P < 0.001), and prolonged operating time (P < 0.001). All postoperative complications were more frequently occurred in patients with POI. The nomogram accurately predicted POI with a concordant index for this model of 0.69. The use of minimal invasive techniques, control of preoperative septic conditions, oral antibiotic bowel preparation and shorter operative time are associated with a decreased rate of POI. External validation is essential for the confirmation and further evaluation of our logistic regression model and nomogram.

Perioperative COX-2 and β-Adrenergic Blockade Improves Metastatic Biomarkers in Breast Cancer Patients in a Phase-II Randomized Trial

Purpose: Translational studies suggest that excess perioperative release of catecholamines and prostaglandins may facilitate metastasis and reduce disease-free survival. This trial tested the combined perioperative blockade of these pathways in breast cancer patients.Experimental Design: In a randomized placebo-controlled biomarker trial, 38 early-stage breast cancer patients received 11 days of perioperative treatment with a β-adrenergic antagonist (propranolol) and a COX-2 inhibitor (etodolac), beginning 5 days before surgery. Excised tumors and sequential blood samples were assessed for prometastatic biomarkers.Results: Drugs were well tolerated with adverse event rates comparable with placebo. Transcriptome profiling of the primary tumor tested a priori hypotheses and indicated that drug treatment significantly (i) decreased epithelial-to-mesenchymal transition, (ii) reduced activity of prometastatic/proinflammatory transcription factors (GATA-1, GATA-2, early-growth-response-3/EGR3, signal transducer and activator of transcription-3/STAT-3), and (iii) decreased tumor-infiltrating monocytes while increasing tumor-infiltrating B cells. Drug treatment also significantly abrogated presurgical increases in serum IL6 and C-reactive protein levels, abrogated perioperative declines in stimulated IL12 and IFNγ production, abrogated postoperative mobilization of CD16^- "classical" monocytes, and enhanced expression of CD11a on circulating natural killer cells.Conclusions: Perioperative inhibition of COX-2 and β-adrenergic signaling provides a safe and effective strategy for inhibiting multiple cellular and molecular pathways related to metastasis and disease recurrence in early-stage breast cancer. Clin Cancer Res; 23(16); 4651-61. ©2017 AACR.

Influence of perioperative nonsteroidal anti-inflammatory drugs on complications after gastrointestinal surgery: A meta-analysis

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a key part of multimodal perioperative analgesia. This study aimed to evaluate the influence of perioperative NSAIDs application on complications after gastrointestinal surgery by using meta-analysis.

METHODS

A systematic review of published literature was conducted by searching computerized databases including PubMed, CBM, Springer, Chinese Academic Journals, and China Info since the databases were published until June 2015. The articles and retrospective references regarding complications after gastrointestinal surgery were collected to compare postoperative complications associated with NSAIDs or other analgesics. After they were assessed by randomized controlled trials and extracted by the standard of the Jadad systematic review, the homogeneous studies were pooled using RevMan 5.3 software. The meta-analysis was performed on five postoperative complications: postoperative anastomotic leak, cardiovascular events, surgical site infection, nausea and vomiting, and intestinal obstruction.

RESULTS

Twelve randomized controlled trials involving 3829 patients met the inclusion criteria. The results of meta-analyses showed the following: (1) postoperative anastomotic leak: NSAIDs (including selective and nonselective NSAIDs) increased the incidence of anastomotic leak [odds ratio (OR)=3.02, 95% confidence interval (CI): 2.16-4.23, p=0.00001]. Further results showed that nonselective NSAIDs significantly increased the incidence of anastomotic leak (OR=2.96, 95% CI: 1.99-4.42, p<0.00001), and selective NSAIDs had no significant difference as compared with the control group using other analgesics (OR=2.27, 95% CI: 0.68-7.56, p=0.18); (2) postoperative cardiovascular events: NSAIDs (selective and nonselective NSAIDs) had no difference when compared with other analgesics (OR=0.50, 95% CI: 0.23-1.12, p=0.09); (3) postoperative surgical site infection: NSAIDs (selective and nonselective NSAIDs) and other analgesics had no difference in surgical site infection (OR=0.77, 95% CI: 0.52-1.15, p=0.20); (4) postoperative nausea and vomiting: NSAIDs (selective and nonselective NSAIDs) decreased the incidence of nausea and vomiting (OR=0.53, 95% CI: 0.34-0.81, p=0.003); (5) postoperative intestinal obstruction: NSAIDs (selective and nonselective NSAIDs) decreased the incidence of intestinal obstruction (OR=0.35, 95% CI: 0.13-0.89, p=0.03).

CONCLUSIONS

The meta-analysis suggests that postoperative NSAIDs, especially nonselective NSAIDs, could increase the incidence of anastomotic leak. NSAIDs could decrease postoperative nausea and vomiting and intestinal obstruction, but showed no difference in cardiovascular events and surgical site infection as compared with other analgesics.

Postoperative Nonsteroidal Anti-inflammatory Drug Use and Intestinal Anastomotic Dehiscence: A Systematic Review and Meta-Analysis

BACKGROUND

Nonsteroidal anti-inflammatory drugs are commonly used analgesics in colorectal surgery. Controversy exists regarding the potential association between these drugs and anastomotic dehiscence.

OBJECTIVE

This study aimed to determine whether postoperative nonsteroidal anti-inflammatory drug use is associated with intestinal anastomotic dehiscence.

DATA SOURCES

PubMed, EMBASE, CENTRAL, and references of included articles were searched without date or language restriction.

STUDY SELECTION

Randomized controlled trials and observational studies that compared postoperative nonsteroidal anti-inflammatory drug use with nonuse and reported on intestinal anastomotic dehiscence were selected.

INTERVENTION

The use of postoperative nonsteroidal anti-inflammatory drugs relative to placebo or nonuse was investigated.

MAIN OUTCOME MEASURES

Risk ratios and adjusted or unadjusted odds ratios for anastomotic dehiscence were pooled across randomized controlled trials and observational studies using DerSimonian and Laird random-effects models.

RESULTS

Among 4395 citations identified, 6 randomized controlled trials (n = 473 patients) and 11 observational studies (n > 20,184 patients) were included. Pooled analyses revealed that nonsteroidal anti-inflammatory drug use was nonsignificantly associated with anastomotic dehiscence in randomized controlled trials (risk ratio, 1.96; 95% CI, 0.74-5.16; I = 0%) and significantly associated with anastomotic dehiscence in observational studies (OR, 1.46; 95% CI, 1.14-1.86; I = 54%). In stratified analyses of observational study data, the pooled OR for anastomotic dehiscence was statistically significant for studies of nonselective nonsteroidal anti-inflammatory drug use (6 studies; > 4900 patients; OR, 2.09; 95% CI, 1.65-2.64; I = 0%), but was not statistically significant for studies of cyclooxygenase-2 selective nonsteroidal anti-inflammatory drug use (3 studies; >697 patients; OR, 1.34; 95% CI, 0.78-2.31; I = 0%).

LIMITATIONS

Studies varied by patient selection criteria, drug exposures, and definitions of anastomotic dehiscence. Analyses of randomized controlled trials and cyclooxygenase-2 selective nonsteroidal anti-inflammatory drugs were potentially underpowered.

CONCLUSIONS

Pooled observational data suggest an association between postoperative nonsteroidal anti-inflammatory drug use and intestinal anastomotic dehiscence. Caution may be warranted in using these medications in patients at risk for this complication.

Risk of perioperative bleeding related to highly selective cyclooxygenase-2 inhibitors: A systematic review and meta-analysis

BACKGROUND

Several literatures reported that highly selective cycloxygenase-2 inhibitors (COX-2 inhibitors) had no effect on platelet function. However, some experts suggested stopping all non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 inhibitors at least five elimination half-lives prior to surgery. We, therefore, systematically summarized the risk of clinical bleeding or platelet dysfunction in healthy or surgical subjects who received COX-2 inhibitors.

METHODS

Two electronic databases, MEDLINE and EMBASE, were searched for randomized, controlled studies published during 1980-December 2015. Additionally, manual search was performed to identify potential eligible studies. Intervention was perioperative use of any available COX-2 inhibitors in current practice (celecoxib, parecoxib, or etoricoxib), compared to non-selective NSAIDs, analgesics, or placebo. Two independent reviewers selected eligible studies, extracted the data, and assessed the quality of the included studies. The primary outcome was postoperative bleeding. All analyses were performed using RevMan-5.3.

RESULTS

Of 3900 abstracts reviewed, 35 studies met the inclusion criteria. The data from 16 out of 35 studies were used in this meta-analysis, and outcomes of other 19 remaining studies were descriptively summarized. COX-2 inhibitors did not significantly increase the risk of postoperative bleeding events (relative risk or RR = 0.92; 95% confidence interval or CI: 0.63-1.33; p = 0.65), intraoperative blood loss (mL) (weighted mean difference or WMD = -4.38; 95% CI: -14.69 to 5.92; p = 0.4), postoperative blood loss (mL) (WMD = -13.89; 95% CI: -30.24 to 2.47; p = 0.10), and 24-h postoperative hemoglobin loss (g/dL) (WMD = 0.47; 95% CI: -0.14 to 1.09; p = 0.13). Platelet function analyzer closure time (second) significantly decreased with the use of COX-2 inhibitors (WMD = -22.22; 95% CI: -44.03 to -0.41; p < 0.00001). In the 19 remaining studies, COX-2 inhibitors did not significantly increase risk of bleeding in both clinical and laboratory outcomes.

CONCLUSION

Highly selective COX-2 inhibitors did not significantly increase the risk of intraoperative, postoperative bleeding, or blood loss. They also had no significant effect on platelet function. Therefore, perioperative, single dose, or short course of COX-2 inhibitors can be safely used in individuals who are undergoing surgery.

Ketorolac Use and Postoperative Complications in Gastrointestinal Surgery

OBJECTIVE

To study the association between ketorolac use and postoperative complications.

BACKGROUND

Nonsteroidal anti-inflammatory drugs may impair wound healing and increase the risk of anastomotic leak in colon surgery. Studies to date have been limited by sample size, inability to identify confounding, and a focus limited to colon surgery.

METHODS

Ketorolac use, reinterventions, emergency department (ED) visits, and readmissions in adults (≥ 18 years) undergoing gastrointestinal (GI) operations was assessed in a nationwide cohort using the MarketScan Database (2008-2012).

RESULTS

Among 398,752 patients (median age 52, 45% male), 55% underwent colorectal surgery, whereas 45% had noncolorectal GI surgery. Five percent of patients received ketorolac. Adjusting for demographic characteristics, comorbidities, surgery type/indication, and preoperative medications, patients receiving ketorolac had higher odds of reintervention (odds ratio [OR] 1.20, 95% confidence interval [CI] 1.08-1.32), ED visit (OR 1.44, 95% CI 1.37-1.51), and readmission within 30 days (OR 1.11, 95% CI 1.05-1.18) compared to those who did not receive ketorolac. Ketorolac use was associated with readmissions related to anastomotic complications (OR 1.20, 95% CI 1.06-1.36). Evaluating only admissions with ≤ 3 days duration to exclude cases where ketorolac might have been used for complication-related pain relief, the odds of complications associated with ketorolac were even greater.

CONCLUSIONS

Use of intravenous ketorolac was associated with greater odds of reintervention, ED visit, and readmission in both colorectal and noncolorectal GI surgery. Given this confirmatory evaluation of other reports of a negative association and the large size of this cohort, clinicians should exercise caution when using ketorolac in patients undergoing GI surgery.

Enhanced recovery protocols for major upper gastrointestinal, liver and pancreatic surgery

BACKGROUND

'Fast-track surgery' or 'enhanced recovery protocol' or 'fast-track rehabilitation', incorporating one or more elements of preoperative education, pain relief, early mobilisation, enteral nutrition and growth factors, may improve health-related quality of life and reduce length of hospital stay and costs. The role of enhanced recovery protocols in major upper gastrointestinal, liver and pancreatic surgery is unclear.

OBJECTIVES

To assess the benefits and harms of enhanced recovery protocols compared with standard care (or usual practice) in major upper gastrointestinal, liver and pancreatic surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Cochrane Library; 2015, Issue 3), MEDLINE, EMBASE and Science Citation Index Expanded until March 2015 to identify randomised trials. We also searched the references of included trials to identify further trials.

SELECTION CRITERIA

We considered only randomised controlled trials (RCTs) performed in people undergoing major upper gastrointestinal, liver and pancreatic surgery, irrespective of language, blinding or publication status for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and independently extracted data. We calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CIs) using both fixed-effect and random-effects models using Review Manager 5, based on available case analysis.

MAIN RESULTS

Ten studies met the inclusion criteria for the review, and nine studies provided information on one or more outcomes for the review. A total of 1014 participants were randomly assigned to the enhanced recovery protocol (499 participants) or standard care (515 participants) in the nine RCTs. Most of the trials included low anaesthetic risk participants with high performance status undergoing different upper gastrointestinal, liver and pancreatic surgeries. Eight trials incorporated more than one element of the enhanced recovery protocol. All of the trials were at high risk of bias. The overall quality of evidence was low or very low.None of the trials reported long-term mortality, medium-term health-related quality of life(three months to one year), time to return to normal activity, or time to return to work. The difference between the enhanced recovery protocol and standard care were imprecise for short-term mortality (enhanced recovery protocol: 4/425 (adjusted proportion = 0.6%); standard care: 1/443 (0.2%); seven trials; 868 participants; RR 2.79; 95% CI 0.44 to 17.73; very low quality evidence), proportion of people with serious adverse events (enhanced recovery protocol: 4/157 (adjusted proportion = 0.6%); standard care: 0/184 (0.0%); two trials; 341 participants; RR 5.57; 95% CI 0.68 to 45.89; very low quality evidence), number of serious adverse events (enhanced recovery protocol: 34/421 (8 per 100 participants); standard care: 46/438 (11 per 100 participants); seven trials; 859 participants; rate ratio 0.72; 95% CI 0.45 to 1.13; very low quality evidence), health-related quality of life (four trials; 373 participants; SMD 0.29; 95% CI -0.04 to 0.62; very low quality evidence) and hospital readmissions (enhanced recovery protocol: 14/355 (adjusted proportion = 3.3%); standard care: 9/378 (2.4%); seven trials; 733 participants; RR 1.4; 95% CI 0.69 to 2.87; very low quality evidence). The enhanced recovery protocol group had a lower proportion of people with mild adverse events (enhanced recovery protocol: 31/254 (adjusted proportion = 10.9%); standard care: 51/271 (18.8%); four trials; 525 participants; RR 0.58; 95% CI 0.39 to 0.85; low quality evidence), fewer number of mild adverse events (enhanced recovery protocol: 69/499 (13 per 100 participants); standard care: 128/515 (25 per 100 participants); nine trials; 1014 participants; rate ratio 0.52; 95% CI 0.39 to 0.70; low quality evidence), shorter length of hospital stay (nine trials; 1014 participants; MD -2.19 days; 95% CI -2.53 to -1.85; low quality evidence) and lower costs (four trials; 282 participants; MD USD -6300; 95% CI -8400 to -4200; low quality evidence) than standard care group.

AUTHORS' CONCLUSIONS

Based on low quality evidence, enhanced recovery protocols may reduce length of hospital stay and costs (primarily because of reduction in hospital stay) in people undergoing major upper gastrointestinal, liver and pancreatic surgeries. However, the validity of the results is uncertain because of the risk of bias in the trials and the way the outcomes were measured. Future RCTs should be conducted with low risk of bias, and measure clinically important outcomes for including the three months to one year period.

Postoperative nonsteroidal anti-inflammatory drugs and risk of anastomotic leak: meta-analysis of clinical and experimental studies

BACKGROUND

Enhanced recovery programs following colorectal resection recommend the use of nonsteroidal anti-inflammatory drugs (NSAIDs) as part of multimodal analgesia. The present study aimed to assess whether postoperative NSAID use increased the risk of anastomotic leak.

METHODS

A systematic review of published literature was performed for studies comparing anastomotic leak following NSAID administration versus control. Meta-analysis was conducted for studies in human patients and experimental animal models. The primary endpoint was anastomotic leak.

RESULTS

The final analysis included 8 studies in humans and 12 experimental animal studies. Use of NSAIDs was significantly associated with anastomotic leak in humans (8 studies, 4,464 patients, odds ratio [OR] 2.14; p < 0.001). This effect was seen with nonselective NSAIDs (6 studies, 3,074 patients, OR 2.37; p < 0.001), but not with selective NSAIDs (4 studies, 1,223 patients, OR 2.32; p = 0.170). There was strong evidence of selection bias from all clinical studies, with additional inconsistent definitions and outcomes assessment. From experimental animal models, anastomotic leak was more likely with NSAID use (ten studies, 575 animals, OR 9.51; p < 0.001). Bursting pressures at day 7 were significantly lower in NSAID versus controls (7 studies, 168 animals, weighted mean difference -35.7 mmHg; p < 0.001).

CONCLUSIONS

Emerging data strongly suggest that postoperative NSAIDs are linked to anastomotic leak, although most studies are flawed and may be describing pre-existing selection bias. However, when combined with experimental data, these increasing concerns suggest caution is needed when prescribing NSAIDs to patients with pre-existing risk factors for leak, until more definitive evidence emerges.

Postoperative ileus: Recent developments in pathophysiology and management

BACKGROUND & AIMS

Postoperative ileus (POI) is a frequent occurrence after abdominal and other types of surgery, and is associated with significant morbidity and costs to health care providers. The aims of this narrative review were to provide an update of classification systems, preventive techniques, pathophysiological mechanisms, and treatment options for established POI.

METHODS

The Web of Science, MEDLINE, PubMed and Google Scholar databases were searched using the key phrases 'ileus', 'postoperative ileus' and 'definition', for relevant studies published in English from January 1997 to August 2014.

RESULTS

POI is still a problematic and frequent complication of surgery. Fluid overload, exogenous opioids, neurohormonal dysfunction, and gastrointestinal stretch and inflammation are key mechanisms in the pathophysiology of POI. Evidence is supportive of thoracic epidural analgesia, avoidance of salt and water overload, alvimopan and gum chewing as measures for the prevention of POI, and should be incorporated into perioperative care protocols. Minimal access surgery and avoidance of nasogastric tubes may also help. Novel strategies are emerging, but further studies are required for the treatment of prolonged POI, where evidence is still lacking.

CONCLUSIONS

Although POI is often inevitable, methods to reduce its duration and facilitate recovery of postoperative gastrointestinal function are evolving rapidly. Utilisation of standardised diagnostic classification systems will help improve applicability of future studies.

Efficacy and safety of low-dose celecoxib in reducing post-operative paralytic ileus after major abdominal surgery

BACKGROUND

A number of interventions have been used to decrease the incidence of post-operative paralytic ileus. A secondary outcome of a randomized controlled study showed that COX-2 inhibitors decreased the incidence of paralytic ileus. We sought to study a large cohort of patients undergoing major abdominal operations who were treated with a COX-2 inhibitor.

METHODS

This is a retrospective review of prospectively collected data. All eligible patients were given a COX-2 inhibitor--celecoxib 100 mg--twice daily starting on the day of surgery until the seventh day post-operatively or discharge, whichever was earlier. The rate of paralytic ileus was calculated and compared with historical data. Secondary outcome measures were the effect of using COX-2 inhibitors on renal function, electrolytes and haemoglobin, morbidity and leak rates.

RESULTS

Two hundred and fifty-two patients were treated with celecoxib; the control arm consisted of 67 historical patients. Of the 252 patients, we had complete data for 235 patients and ileus in 17 patients (7.23%) compared with 13.4% in the control group (P = 0.05). Subgroup analysis showed ileus in 5.45% of colectomy patients and 6.36% of patients who have had a colectomy and high anterior resection. There was no detriment of measured blood tests. There were leaks in two treated patients, both of whom did not require a laparotomy.

CONCLUSIONS

The use of low-dose COX-2 inhibitor over a short period of time decreases the paralytic ileus rates and does not cause any significant morbidity.

Ascending excitatory neural pathways modulate slow phasic myogenic contractions in the isolated human colon

BACKGROUND

In animal models, enteric reflex pathways have potent effects on motor activity; their roles have been much less extensively studied in human gut. The aim of this study was to determine if ascending excitatory interneuronal pathways can modulate spontaneous phasic contractions in isolated preparations of human colonic circular muscle.

METHODS

Human colonic preparations were cut into T shapes, with vertical bar of the 'T' pharmacologically isolated. Electrical stimulation and the nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), were applied to the isolated region and circular muscle contractile activity was measured from the cross-bar of the T, more than 10 mm orally from the region of stimulation.

KEY RESULTS

The predominant form of spontaneous muscle activity consisted of tetrodotoxin-resistant, large amplitude, slow phasic contractions (SPCs), occurring at average intervals of 124 ± 68 s. Addition of a high concentration of hexamethonium (1 mmol L(-1)) to the superfusing solution significantly increased the interval between SPCs to 278.1 ± 138.3 s (P < 0.005). Focal electrical stimulation more than 10 mm aboral to the muscle recording site advanced the onset of the next SPC, and this effect persisted in hexamethonium. However, the effect of electrical stimulation was blocked by tetrodotoxin (TTX, 1 μmol L(-1)). Application of the nicotinic agonist DMPP (1 mmol L(-1)) to the aboral chamber often stimulated a premature SPC (n = 4).

CONCLUSIONS & INFERENCES

The major form of spontaneous contractility in preparations of human colonic circular muscle is SPCs, which are myogenic in origin. Activation of ascending excitatory neural pathways, which involve nicotinic receptors, can modulate the timing of SPCs and thus influence human colonic motility.

Defining postoperative ileus: results of a systematic review and global survey

BACKGROUND

There is a lack of an internationally accepted standardised clinical definition for postoperative ileus (POI). This has made it difficult to estimate incidence and identify risk factors and has compromised external validity of clinical trials.

AIM

To clarify terminology of POI and propose concise, clinically quantifiable definitions.

METHODS

A systematic review extracted definitions from randomised trials published between 1996 and 2011 investigating POI after abdominal surgery. This was followed by a global survey seeking opinions of those who have published in the field.

RESULTS

Definitions were extracted from 52 identified trials. Responses were received in the survey from 45 of 118 corresponding authors. Data were amalgamated to synthesise the following definitions: postoperative ileus (POI) "interval from surgery until passage of flatus/stool AND tolerance of an oral diet"; prolonged POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation occurring on or after day 4 postoperatively without prior resolution of POI"; recurrent POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation, occurring after apparent resolution of POI". Concordance of the latter two definitions with survey responses were ≥75 %.

CONCLUSION

We have proposed standardised endpoints for use in future studies to facilitate objective comparison of competing interventions.

Management of prolonged post-operative ileus: evidence-based recommendations

BACKGROUND

Prolonged post-operative ileus (PPOI) occurs in up to 25% of patients following major elective abdominal surgery. It is associated with a higher risk of developing post-operative complications, prolongs hospital stay and confers a significant financial load on health-care institutions. Literature outlining best-practice management strategies for PPOI is nebulous. The aim of this text was to review the literature and provide concise evidence-based recommendations for its management.

METHODS

A literature search through the Ovid MEDLINE, EMBASE, Google Scholar and Cochrane databases was performed from inception to July 2012 using a combination of keywords and MeSH terms. Review of the literature was followed by synthesis of concise recommendations for management accompanied by Strength of Recommendation Taxonomy (either A, B or C).

RESULTS

Recommendations for management include regular evaluation and correction of electrolytes (B); review of analgesic prescription with weaning of narcotics and substitution with regular paracetamol, regular non-steroidal anti-inflammatory drugs if not contraindicated, and regular or as-required Tramadol (A); nasogastric decompression for those with nausea or vomiting as prominent features (C); isotonic dextrose-saline crystalloid maintenance fluids administered within a restrictive regimen (B); balanced isotonic crystalloid replacement fluids containing supplemental potassium, in equivalent volume to losses (C); regular ambulation (C); parenteral nutrition if unable to tolerate an adequate oral intake for more than 7 days post-operatively (A) and exclusion of precipitating pathology or alternate diagnoses if clinically suspected (C).

CONCLUSIONS

Recommendations have a variable and frequently inconsistent evidence base. Further research is required to validate many of the outlined recommendations and to investigate novel interventions that may be used to shorten duration of PPOI.

Nonsteroidal anti-inflammatory drugs and anastomotic dehiscence in bowel surgery: systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

Nonsteroidal anti-inflammatory drugs are a key component of contemporary perioperative analgesia. Recent experimental and observational clinical data suggest an associated increased incidence of anastomotic dehiscence in bowel surgery.

OBJECTIVE

The aim of this study was to conduct a systematic review and meta-analysis of anastomotic dehiscence in randomized, controlled trials of perioperative nonsteroidal anti-inflammatory drugs.

DATA SOURCES

Published and unpublished trials in any language reported 1990 or later were identified by searching electronic databases, bibliographies, and relevant conference proceedings.

STUDY SELECTION

Trials of adults undergoing bowel surgery randomly assigned to perioperative nonsteroidal anti-inflammatory drugs or control were included. The number of patients with a bowel anastomosis and the incidence of anastomotic dehiscence had to be reported or be available from authors for the study to be included.

INTERVENTION

At least 1 dose of a nonsteroidal anti-inflammatory drug was given perioperatively within 48 hours of surgery.

MAIN OUTCOME MEASURES

The primary outcome measured was 30-day incidence of anastomotic dehiscence as defined by authors.

RESULTS

Six trials comprising 480 patients having a bowel anastomosis met inclusion criteria. In 4 studies, anastomotic dehiscence rates were higher in the intervention groups. Overall rates were 14/272 participants (5.1%) in intervention arms vs 5/208 (2.4%) in control arms. Peto OR was 2.16 (95% CI 0.85, 5.53; p = 0.11), and there was no heterogeneity between studies (I statistic 0%).

LIMITATIONS

Sizes of available trials were small, preventing firm conclusions and subset analysis of drugs of different cyclooxygenase specificity. A precise and consistent definition of anastomotic dehiscence was not used across trials.

CONCLUSIONS

A statistically significant difference in incidence of anastomotic dehiscence was not demonstrated. However, the Peto OR of 2.16 (0.85, 5.53) and lack of heterogeneity between trials suggest that this finding may be due to a lack of power of the available data rather than a lack of effect.

New therapeutic strategies for postoperative ileus

Patients undergoing an abdominal surgical procedure develop a transient episode of impaired gastrointestinal motility or postoperative ileus. Importantly, postoperative ileus is a major determinant of recovery after intestinal surgery and leads to increased morbidity and prolonged hospitalization, which is a great economic burden to health-care systems. Although a variety of strategies reduce postoperative ileus, including multimodal postoperative rehabilitation (fast-track care) and minimally invasive surgery, none of these methods have been completely successful in shortening the duration of postoperative ileus. The aetiology of postoperative ileus is multifactorial, but insights into the pathogenesis of postoperative ileus have identified intestinal inflammation, triggered by surgical handling, as the main mechanism. The importance of this inflammatory response in postoperative ileus is underscored by the beneficial effect of pharmacological interventions that block the influx of leukocytes. New insights into the pathophysiology of postoperative ileus and the involvement of the innate and the adaptive (T-helper type 1 cell-mediated immune response) immune system offer interesting and important new approaches to prevent postoperative ileus. In this Review, we discuss the latest insights into the mechanisms behind postoperative ileus and highlight new strategies to intervene in the postoperative inflammatory cascade.

Colorectal cancer surgery 2000-2008: evaluation of a prospective database

BACKGROUND

  Colorectal cancer is a common cause of cancer death in Australia and is primarily managed operatively. Surgical databases are valuable in monitoring performance in cancer treatment and detecting problems and trends.

METHODS

  Diagnostic and treatment variables and short-term outcomes were gathered prospectively for patients undergoing resection for colorectal cancer over a 9-year period. Survival data were obtained by linkage to state and interstate death indices.

RESULTS

  Eight hundred and five patients underwent resection for colorectal cancer during the study period. Overall 5-year survival was 61%. Five-year cancer-specific survival was 73%. Five-year cancer-specific survival for Australian Clinico-Pathological Staging (ACPS) stages A, B, C and D was 96, 80, 61 and 19%, respectively (P < 0.0001). Emergency presentations showed diminished survival (59% versus 75%, P < 0.0001) after controlling for age and stage (hazard ratio (HR) 1.78, P= 0.005), as did transfusion recipients (63% versus 74%, P= 0.0014; HR 1.78, P= 0.004). Anastomotic leak did not affect survival in multivariable analysis. Non-cancer causes accounted for 26% deaths, primarily comprising cardiovascular deaths in the elderly.

DISCUSSION

  High case ascertainment, data completeness and accuracy can be obtained with prospective, independently gathered data linked electronically to national death records. Survival for colorectal cancer in South Australia continues to improve. Close follow-up for disease recurrence is warranted for transfusion recipients, emergencies and advanced disease. Locally managed databases with linkage to state registries and other institutions are powerful methods to improve data quality and surgical care at a national level.

Risk of anastomotic leakage with use of NSAIDs after gastrointestinal surgery

PURPOSE

Analgesic regimes to avoid opioid-related adverse effects have been recommended in gastrointestinal surgery. Non-steroidal anti-inflammatory drugs (NSAIDs) are an important component of opioid sparing regimes in that these drugs indirectly reduce pain by inhibiting inflammation. Although beneficial for most surgical patients, animal studies and recent clinical studies suggest a harmful effect on new intestinal anastomoses by increasing the rate of leakage. NSAIDs may indirectly disturb anastomotic healing by inhibiting inflammation as an integrated part of the wound healing process in an early, critical phase after surgery.

METHODS

A literature review based on a structured search in PubMed of clinical and experimental studies investigating the effects of NSAIDs on anastomotic healing and leakage rates after intestinal surgery, as well as proposed mechanisms and effects studied in animal models.

RESULTS

Three recent observational cohort studies (accumulated n = 882) indicate an increased rate of anastomotic leakages (15-21%) associated with cyclooxygenase-2 (COX-2) selective NSAIDs after intestinal surgery compared to the leakage rates in controls or historical cohorts (1-4%). Three prospective studies on related topics contain relevant data on NSAIDs and are compared to these studies. Several experimental animal studies support an increased risk for anastomotic leakage with the use of NSAIDs.

CONCLUSION

The reported effects of NSAIDs on anastomotic healing suggest an increased risk for leakage. A better understanding of the complex interactions of NSAID-induced inhibition on anastomotic healing is a prerequisite for the safe use of NSAIDs. Until more data are available, a careful use of NSAIDs may be warranted in gastrointestinal anastomotic surgery.

Gastric emptying is delayed in transgastric NOTES: a randomized study in swine

AIM

The aim of this study was to evaluate the restoration of gastrointestinal motility after NOTES using capsule endoscopy (CE).

MATERIALS AND METHODS

Twenty adult Yorkshire pigs were randomly assigned to four groups: transgastric NOTES (gNOTES), transrectal NOTES (rNOTES), transvaginal NOTES (vNOTES), and laparoscopy (LAP). At the end of a 30-min peritoneoscopy with identification of seven predetermined organs, an array of eight receivers and the recorder were attached to the abdominal wall. The CE was delivered into the antrum with the help of an endoscope and a polypectomy snare. Animals were kept alive for 14 d.

RESULTS

Median time for surgery was longer in gNOTES (56 min, range 47-63) and vNOTES (54 min, range 44-79) than in LAP (32 min, range 32-33; P < 0.05 and P < 0.01) and in rNOTES (45.5 min, range 33-56) (P = ns). This increase was related to a larger incision and longer closure times. Images from the CE were successfully retrieved in 19 cases. The CE was retained in the stomach in all animals in gNOTES (459 min; range 360-600), but only in one animal in rNOTES and vNOTES and in none in the LAP group. Failure of passage of the CE beyond the stomach was associated with gNOTES and longer closure of the incision. Animals in the gNOTES group gained less weight than the others and this change was statistical significant when compared with vNOTES animals (1.7 kg, range -1.98 to 4.5 versus 8.4 kg, range 5.8 to 11.45; P < 0.01).

CONCLUSION

Gastric emptying is delayed after gNOTES peritoneoscopy compared with rNOTES, vNOTES, and LAP and this effect is associated with less weight gain.

Enteric nervous system in the small intestine: pathophysiology and clinical implications

The digestive system is endowed with its own, local nervous system, referred to as the enteric nervous system (ENS). Given the varied functions of small intestine, its ENS has developed individualized characteristics relating to motility, secretion, digestion, and inflammation. The ENS regulates the major enteric processes such as immune response, detecting nutrients, motility, microvascular circulation, intestinal barrier function, and epithelial secretion of fluids, ions, and bioactive peptides. Remarkable progress has been made in understanding the signaling pathways in this complex system and how they work. In this article, we focus on recent advances that have led to new insights into small intestinal ENS function and the development of new therapies.

Interplay between inflammation, immune system and neuronal pathways: Effect on gastrointestinal motility

Sepsis is a systemic inflammatory response representing the leading cause of death in critically ill patients, mostly due to multiple organ failure. The gastrointestinal tract plays a pivotal role in the pathogenesis of sepsis-induced multiple organ failure through intestinal barrier dysfunction, bacterial translocation and ileus. In this review we address the role of the gastrointestinal tract, the mediators, cell types and transduction pathways involved, based on experimental data obtained from models of inflammation-induced ileus and (preliminary) clinical data. The complex interplay within the gastrointestinal wall between mast cells, residential macrophages and glial cells on the one hand, and neurons and smooth muscle cells on the other hand, involves intracellular signaling pathways, Toll-like receptors and a plethora of neuroactive substances such as nitric oxide, prostaglandins, cytokines, chemokines, growth factors, tryptases and hormones. Multidirectional signaling between the different components in the gastrointestinal wall, the spinal cord and central nervous system impacts inflammation and its consequences. We propose that novel therapeutic strategies should target inflammation on the one hand and gastrointestinal motility, gastrointestinal sensitivity and even pain signaling on the other hand, for instance by impeding afferent neuronal signaling, by activation of the vagal anti-inflammatory pathway or by the use of pharmacological agents such as ghrelin and ghrelin agonists or drugs interfering with the endocannabinoid system.