Effectiveness of mechanical bowel preparation versus no preparation on anastomotic leakage in colorectal surgery: a systematic review and meta-analysis

Impact of pre-operative mechanical bowel preparation in preventing post-operative anastomotic leak: A meta-analysis

Colorectal operations are amongst the most frequently performed surgical procedures worldwide. Success of colorectal surgery is significantly influenced by occurrence of postoperative complications; Efforts are directed in detecting risk factors for these complications and trials to avoid risk factors to reduce complications rate. This study was conducted to assess the impact of mechanical bowel preparation in preventing post-operative anastomotic leakage in adult patients undergoing elective restorative colorectal surgery. A Systematic review and meta-analysis of randomized controlled trials comparing patients receiving mechanical bowel preparation with those receiving no mechanical bowel preparation among adult patients undergoing laparoscopic or open elective restorative colorectal surgery. The search resulted in 1237 potentially relevant studies. Screening of titles and abstracts led to 299 studies, which were reviewed in full. Finally, 11 studies were included in the current study. number of participants in the included studies ranged from 63 to 29,739 with a mean age of 62.98 years in a range from 41 to 73 years of age. Studies featured primarily colorectal carcinoma as an indication for surgery (range 65-100 %). analysis of data was done to assess the impact of pre-operative mechanical bowel preparation on the rate of anastomotic leaks, surgical site infections, intra-abdominal collections, mortality rate, need for reoperation. and hospital length of stay. Mechanical bowel preparation appears to reduce anastomotic leaks and shorten length of hospitalization but does not significantly impact other clinical outcomes in patients undergoing elective laparoscopic or open restorative colorectal surgery.

The effect of preoperative mechanical bowel preparation in paediatric bowel surgery on postoperative wound related complications: A meta-analysis

Mechanical bowel preparation (MBP), a routine nursing procedure before paediatric bowel surgery, is widely should in clinical practice, but its necessity remains controversial. In a systematic review and meta-analysis, we evaluated the effect of preoperative MBP in paediatric bowel surgery on postoperative wound-related complications in order to analyse the clinical application value of MBP in paediatric bowel surgery. As of November 2023, we searched four online databases: the Cochrane Library, Embase, PubMed, and Web of Science. Two investigators screened the collected studies against inclusion and exclusion criteria, and ROBINS-I was used to evaluate the quality of studies. Using RevMan5.3, a meta-analysis of the collected data was performed, and a fixed-effect model or a random-effect model was used to analyse OR, 95% CI, SMD, and MD. A total of 11 studies with 2556 patients were included. Most of studies had moderate-to-severe quality bias. The results of meta-analysis showed no statistically significant difference in the incidence of complications related to postoperative infections in children with MBP before bowel surgery versus those with No MBP, wound infection (OR 1.11, 95% CI:0.76 ~ 1.61, p = 0.59, I2 = 5%), intra-abdominal infection (OR 1.26, 95% CI:0.58 ~ 2.77, p = 0.56, I2 = 9%). There was no significant difference in the risk of postoperative bowel anastomotic leak (OR 1.07, 95% CI:0.68 ~ 1.68, p = 0.78, I2 = 12%), and anastomotic dehiscence (OR 1.67, 95% CI:0.13 ~ 22.20, p = 0.70, I2 = 73%). Patients' intestinal obstruction did not show an advantage of undergoing MBP preoperatively, with an incidence of intestinal obstruction (OR 1.95, 95% CI:0.55 ~ 6.93, p = 0.30, I2 = 0%). Based on existing evidence that preoperative MBP in paediatric bowel surgery did not reduce the risk of postoperative wound complications, we cautiously assume that MBP before surgery is unnecessary for children undergoing elective bowel surgery. However, due to the limited number of study participants selected for this study and the overall low quality of evidence, the results need to be interpreted with caution. It is suggested that more high quality, large-sample, multicenter clinical trials are required to validate our findings.

The Impact of Mechanical Bowel Preparation and Oral Antibiotics in Colorectal Cancer Surgery (MECCA Study): A Prospective Randomized Clinical Trial

Background: Colorectal cancer surgery has been associated with surgical site infections (SSIs), leading to an increase in postoperative morbidity, length of stay and total cost. The aim of the present randomized study was to investigate the relationship between the preoperative administration of oral antibiotic therapy and SSI rate, as well as other postoperative outcomes in patients undergoing colorectal cancer surgery. Material and Methods: Patients who underwent colorectal cancer surgery in a university surgical department were included in the present study. Patients were randomized into two groups using the "block randomization" method. The intervention group received three doses of 400 mg rifaximin and one dose of 500 mg metronidazole per os, as well as mechanical bowel preparation the day before surgery. The control group underwent only mechanical bowel preparation the day before surgery. The study has been registered in ClinicalTrials.gov (NCT03563586). Results: Two hundred and five patients were finally included in the present study, 97 of whom received preoperative antibiotic therapy per os (intervention group). Patients of this group demonstrated a significantly lower SSI rate compared with patients who did not receive preoperative antibiotic therapy (7% vs. 16%, p = 0.049). However, preoperative antibiotic administration was not correlated with any other postoperative outcome (anastomotic leak, overall complications, readmissions, length of stay). Conclusions: Preoperative antibiotic therapy in combination with mechanical bowel preparation seemed to be correlated with a lower SSI rate after colorectal cancer surgery.

Mechanical bowel preparations not supported in elective colo-rectal surgeries with anastomosis: A retrospective study

OBJECTIVE

To analyze the risk and benefit of bowel preparations in elective colo-rectal surgery.

BACKGROUND

Mechanical bowel preparations (MBPs) have been popularized in colo-rectal surgery since studies in the 1970s, but recent data has called their use into question and examined complication rates between patients with and without bowel preparations.

METHODS

A retrospective case-review was performed consisting of 1237 elective colo-rectal surgeries performed by two surgeons between 2008 and 2021. Patients received either a MBP, a mechanical bowel preparation with oral antibiotics (OAMBP), oral antibiotics alone (OA), or no bowel preparation; some patients across all categories received an enema.

RESULTS

Bowel preparations combined (MBP and OAMBP) totaled 436 patients and showed no statistically significant difference (P > .05) in primary outcomes of wound infection and anastomotic leak when compared to the 636 patients without a bowel preparation and 165 patients with OA. The analysis controlled for comorbidities and presence of enema. Of secondary outcomes, urinary tract infections (UTIs) were significantly more common in patients who received a bowel preparation (P = .047). All other outcomes showed no significant difference between groups, including complications on day of surgery; complications, readmission with and without surgery, and ileus formation within 30 days of surgery; sepsis; pneumonia; and length of stay (LOS). The presence of enemas did not have a statistically significant effect on outcomes.

CONCLUSIONS

This study's data does not support the routine use of MBPs in elective colo-rectal surgery and draws into further question whether MBPs should remain standard of care.

How to reduce the colorectal anastomotic leakage? The MIRACLe protocol experience in a cohort in a single high-volume centre

This article reports the results of a novel perioperative treatment implementing the gut microbiota to prevent anastomotic fistula and leakage (AL) in patients undergoing laparoscopic colorectal resections for cancer and represents the continuation of our pilot study on 60 cases. A series of 131 patients underwent elective colorectal surgery at the S. Eugenio Hospital (Rome-Italy) between December 1, 2020, and November 30, 2022, and received a perioperative preparation following the Microbiota Implementation to Reduce Anastomotic Colorectal Leaks (MIRACLe) protocol comprising oral antibiotics, mechanical bowel preparation and perioperative probiotics. The results obtained in the MIRACLe group (MG) were compared to those registered in a Control group (CG) of 500 patients operated on between March 2015 and November 30, 2020, who received a standard ERAS protocol. Propensity score-matching (PSM) analysis was performed to overcome patients' selection bias. Patients were categorised according to perioperative preparation (MIRACLe protocol vs standard ERAS protocol) into two groups: 118 patients were in post-matched MIRACLe group (pmMG) and 356 were in post-matched Control group (pmCG). In the pmMG, only 2 anastomotic leaks were registered, and the incidence of AL was just 1.7% vs. 6.5% in the pmCG (p = 0.044). The incidence of surgical site infections (1.7% vs. 3.1%; p = 0.536), reoperations (0.8% vs. 4.2%; p = 0.136) and postoperative mortality (0% vs. 2.0%; p = 0.200) was lower in pmMG. Additionally, the postoperative outcomes were better: the times to first flatus, to first stool and to oral feeding were shorter (1 vs. 2, 2 vs. 3 and 2 vs. 3 days, respectively; p < 0.001). The postoperative recovery was faster, with a shorter time to discharge (5 vs. 6 days; p < 0.001). The MIRACLe protocol was confirmed to be safe and significantly able to reduce anastomotic leaks in patients receiving elective laparoscopic colorectal surgery for cancer.

The role of preoperative mechanical bowel preparation and oral antibiotics in prevention of anastomotic leakage following restorative resection for primary rectal cancer - a systematic review and meta-analysis

PURPOSE

Anastomotic leakage after colorectal cancer resection is a feared postoperative complication seen among up till 10-20% of patients, with a higher risk following rectal resection than colon resection. Recent studies suggest that the combined use of preoperative mechanical bowel preparation and oral antibiotics may have a preventive effect on anastomotic leakage. This systematic review aims to explore the association between preoperative mechanical bowel preparation combined with oral antibiotics and the risk of anastomotic leakage following restorative resection for primary rectal cancer.

METHODS

Three databases were systematically searched in February 2022. Studies reporting anastomotic leakage rate in patients, who received mechanical bowel preparation and oral antibiotics before elective restorative resection for primary rectal cancer, were included. A meta-analysis was conducted based on the risk ratios of anastomotic leakage.

RESULTS

Among 839 studies, 5 studies met the eligibility criteria. The median number of patients were 6111 (80-29,739). The combination of preoperative mechanical bowel preparation and oral antibiotics was associated with a decreased risk of anastomotic leakage (risk ratio = 0.52 (95% confidence interval 0.39-0.69), p-value < 0.001). Limitations included a low number of studies, small sample sizes and the studies being rather heterogenous.

CONCLUSION

This systematic review and meta-analysis found that the use of mechanical bowel preparation and oral antibiotics is associated with a decreased risk of anastomotic leakage among patients undergoing restorative resection for primary rectal cancer. The limitations of the review should be taken into consideration when interpreting the results.

Dysbiosis and Gastrointestinal Surgery: Current Insights and Future Research

Surgery of the gastrointestinal tract can result in deep changes among the gut commensals in terms of abundance, function and health consequences. Elective colorectal surgery can occur for neoplastic or inflammatory bowel disease; in these settings, microbiota imbalance is described as a preoperative condition, and it is linked to post-operative complications, as well. The study of bariatric patients led to several insights into the role of gut microbiota in obesity and after major surgical injuries. Preoperative dysbiosis and post-surgical microbiota reassessment are still poorly understood, and they could become a key part of preventing post-surgical complications. In the current review, we outline the most recent literature regarding agents and molecular pathways involved in pre- and post-operative dysbiosis in patients undergoing gastrointestinal surgery. Defining the standard method for microbiota assessment in these patients could set up the future approach and clinical practice.

Evaluation of clinical prognostic variables on short-term outcome for colorectal cancer surgery: An overview and minimum dataset

INTRODUCTION

Surgery for colorectal cancer is associated with post-operative morbidity and mortality. Multiple systematic reviews have reported on individual factors affecting short-term outcome following surgical resection. This umbrella review aims to synthesize the available evidence on host and other factors associated with short-term post-operative complications.

METHODS

A comprehensive search identified systematic reviews reporting on short-term outcomes following colorectal cancer surgery using PubMed, Cochrane Database of Systematic Reviews and Web of Science from inception to 8th September 2020. All reported clinicopathological variables were extracted from published systematic reviews.

RESULTS

The present overview identified multiple validated factors affecting short-term outcomes in patients undergoing colorectal cancer resection. In particular, factors consistently associated with post-operative outcome differed with the type of complication; infective, non-infective or mortality. A minimum dataset was identified for future studies and included pre-operative age, sex, diabetes status, body mass index, body composition (sarcopenia, visceral obesity) and functional status (ASA, frailty). A recommended dataset included antibiotic prophylaxis, iron therapy, blood transfusion, erythropoietin, steroid use, enhance recovery programme and finally potential dataset included measures of the systemic inflammatory response CONCLUSION: A minimum dataset of mandatory, recommended, and potential baseline variables to be included in studies of patients undergoing colorectal cancer resection is proposed. This will maximise the benefit of such study datasets.

Risk Factors and Preventive Measures for Anastomotic Leak in Colorectal Cancer

Anastomotic leak (AL) represents one of the most detrimental complications after colorectal surgery. The patient-related factors and surgery-related factors leading to AL have been identified in previous studies. Through early identification and timely adjustment of risk factors, preventive measures can be taken to reduce potential AL. However, there are still many problems associated with AL. The debate about preventive measures such as preoperative mechanical bowel preparation (MBP), intraoperative drainage, and surgical scope also continues. Recently, the gut microbiota has received more attention due to its important role in various diseases. Although the underlying mechanisms of gut microbiota on AL have not been validated completely, new strategies that manipulate intrinsic mechanisms are expected to prevent and treat AL. Moreover, laboratory examinations for AL prediction and methods for blood perfusion assessment are likely to be promoted in clinical practice. This review outlines possible risk factors for AL and suggests some preventive measures in terms of patient, surgery, and gut microbiota.

Enhanced recovery after surgery: Current status and future progress

Enhanced Recovery After Surgery (ERAS) pathways were first introduced almost a quarter of a century ago and represent a paradigm shift in perioperative care that reduced postoperative complications and hospital length of stay, improved postoperative quality of life, and reduced overall healthcare costs. Gradual recognition of the generalizability of the interventions and transferable improvements in postoperative outcomes, led them to become standard of care for several surgical procedures. In this article, we critically review the current status of ERAS pathways, address related controversies, and propose measures for future progress.

Enhanced recovery after surgery (ERAS) in cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC): a cross-sectional survey

OBJECTIVES

Enhanced recovery after surgery (ERAS) protocols have been questioned in patients undergoing cytoreductive surgery (CRS) with/without hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal malignancies. This survey was performed to study clinicians' practice about ERAS in patients undergoing CRS-HIPEC.

METHODS

An online survey, comprising 76 questions on elements of prehabilitation (n=11), preoperative (n=8), intraoperative (n=16) and postoperative (n=32) management, was conducted. The respondents included surgeons, anesthesiologists, and critical care specialists.

RESULTS

The response rate was 66% (136/206 clinicians contacted). Ninety-one percent of respondents reported implementing ERAS practices. There was encouraging adherence to implement the prehabilitation (76-95%), preoperative (50-94%), and intraoperative (55-90%) ERAS practices. Mechanical bowel preparation was being used by 84.5%. Intra-abdominal drains usage was 94.7%, intercostal drains by 77.9% respondents. Nasogastric drainage was used by 84% of practitioners. The average hospital stay was 10 days as reported by 50% of respondents. A working protocol and ERAS checklist have been designed, based on the results of our study, following recent ERAS-CRS-HIPEC guidelines. This protocol will be prospectively validated.

CONCLUSIONS

Most respondents were implementing ERAS practices for patients undergoing CRS-HIPEC, though as an extrapolation of colorectal and gynecological guidelines. The adoption of postoperative practices was relatively low compared to other perioperative practices.

Role of mechanical and oral antibiotic bowel preparation in children with Hirschsprung's disease undergoing colostomy closure and pull-through

BACKGROUND

Mechanical and oral antibiotic bowel preparation (MOABP) has been performed routinely before colorectal surgery in children, but the necessity was questioned recently. We evaluated the utility of MOABP in children with Hirschsprung's disease (HSCR) undergoing colostomy closure and pull-through.

METHODS

The medical records of pediatric patients with HSCR who underwent colostomy closure and pull-through in a single center from January 2010 to January 2020 were reviewed. The use of MOABP was noted. The incidence of postoperative complications, duration of postoperative antibiotic therapy, total hospital cost and length-of-stay were compared between patients receiving MOABP and no bowel preparation (NBP).

RESULTS

A total of 64 patients were included in the study: 33 received MOABP and 31 had NBP. The respective postoperative complications in the MOABP and NBP groups were: intra-abdominal infection (18.2% vs. 29.0%), wound infection (9.1% vs. 16.1%), anastomotic leak (0 vs. 0), intestinal obstruction (6.1% vs. 0) and enterocolitis (3.03% vs. 12.90%). The duration of antibiotic therapy was 4.91±4.21 and 5.23±3.77 days (P=0.75) and hospitalization was 18.21±7.26 and 16.26±6.63 days (P=0.27) respectively. The total hospital cost in the MOABP group (4,720.14±1,858.89 USD) was higher than in the NBP group (3,749.06±2,009.97 USD) (P=0.049).

CONCLUSIONS

We did not find any clear benefit of MOABP in children with HSCR before colostomy closure and pull-through. However, a multicenter randomized controlled trial is needed to more definitely determine the best preoperative approach for children with HSCR.

Intestinal Microbiota in Colorectal Cancer Surgery

The intestinal microbiota consists of numerous microbial species that collectively interact with the host, playing a crucial role in health and disease. Colorectal cancer is well-known to be related to dysbiotic alterations in intestinal microbiota. It is evident that the microbiota is significantly affected by colorectal surgery in combination with the various perioperative interventions, mainly mechanical bowel preparation and antibiotic prophylaxis. The altered postoperative composition of intestinal microbiota could lead to an enhanced virulence, proliferation of pathogens, and diminishment of beneficial microorganisms resulting in severe complications including anastomotic leakage and surgical site infections. Moreover, the intestinal microbiota could be utilized as a possible biomarker in predicting long-term outcomes after surgical CRC treatment. Understanding the underlying mechanisms of these interactions will further support the establishment of genomic mapping of intestinal microbiota in the management of patients undergoing CRC surgery.

Best practices in bowel preparation for colorectal surgery: a 2020 overview

INTRODUCTION

Cohort studies have recently initiated a paradigm shift in the field of preoperative bowel preparation. Indeed, the adjunction of oral antibiotics (OAB) to mechanical bowel preparation (MBP) is now the gold standard for the American guidelines. However, this strategy is highly controverted.

AREAS COVERED

This review was an up-to-date analysis of literature on bowel preparation. We conducted a systematic review for randomized controlled trials (RCTs) and meta-analyses published since 2009. A non-exhaustive overview of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) cohort studies and the international guidelines was also given, and future leads were discussed.

EXPERT OPINION

The methodology of the ACS NSQIP studies did not allow a strong conclusion in favor of the association MBP+OAB. Besides, guidelines were not univocal, with non-American guidelines promoting no preparation at all. RCTs favored OAB alone: indeed, MBP+OAB showed no benefits in terms of surgical site infection (SSI) except when compared to MBP alone, while OAB alone seemed superior to no preparation. Likewise, the meta-analyses also favored OAB alone in terms of overall SSI and organ space infection. Large RCTs are currently running and may change these conclusions. Finally, microbiota is a future lead for personalized OAB.

Prospective randomised controlled trial using the REthinking Clinical Trials (REaCT) platform and National Surgical Quality Improvement Program (NSQIP) to compare no preparation versus preoperative oral antibiotics alone for surgical site infection rates in elective colon surgery: a protocol

INTRODUCTION

Despite 40 randomised controlled trials (RCTs) investigating preoperative oral antibiotics (OA) and mechanical bowel preparation (MBP) to reduce surgical site infection (SSI) rate following colon surgery, there has never been an RCT published comparing OA alone versus no preparation. Of the four possible regimens (OA alone, MBP alone, OA plus MBP and no preparation), randomised evidence is conflicting for studied groups. Furthermore, guidelines vary, with recommendations for OA alone, OA plus MBP or no preparation. The National Surgical Quality Improvement Program (NSQIP) has automated data collection for surgical patients. Similarly, the 'REthinking Clinical Trials' (REaCT) platform increases RCT enrolment by simplifying pragmatic trial design. In this novel RCT protocol, we combine REaCT and NSQIP to compare OA alone versus no preparation for SSI rate reduction in elective colon surgery. To our knowledge, this is the first published RCT protocol that leverages NSQIP for data collection. In our feasibility study, 67 of 74 eligible patients (90%) were enrolled and 63 of 67 (94%) were adherent to protocol. The 'REaCT-NSQIP' trial design has great potential to efficiently generate level I evidence for other perioperative interventions.

METHODS AND ANALYSIS

SSI rates following elective colorectal surgery after preoperative OA or no preparation will be compared. We predict 45% relative rate reduction of SSI, improvement in length of stay, reduced costs and increased quality of life, with similar antibiotic-related complications. Consent, using the 'integrated consent model', and randomisation on a mobile device are completed by the surgeon in a single clinical encounter. Data collection for the primary end point is automatic through NSQIP. Analysis of cost per weighted case, cost utility and quality-adjusted life years will be done.

ETHICS AND DISSEMINATION

This study is approved by The Ontario Cancer Research Ethics Board. Results will be disseminated in surgical conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03663504; Pre-results, recruitment phase.

[Oral antibiotic prophylaxis for bowel decontamination before elective colorectal surgery : Current body of evidence and recommendations]

Despite a growing body of evidence from randomized controlled studies, register data and meta-analyses, there is an ongoing controversy about decontamination of the digestive tract before elective colorectal surgery. Currently, mechanical bowel preparation alone can no longer be recommended as there is a lack of evidence for an advantage in terms of risk reduction for infectious complications, anastomotic leakage, morbidity and mortality. In contrast, the administration of oral antibiotics in addition to the obligatory intravenous single shot antibiotic prophylaxis has shown an additive reduction of the risk of up to 50% for the occurrence of postoperative infectious complications; however, due to a lack of data it is unclear if mechanical bowel preparation could even improve the positive effects of combined intravenous and oral antibiotics. Therefore, further studies are necessary. At the current time the occurrence of anastomotic leakage cannot be prevented, independent of whether preoperative bowel decontamination is performed.

Early anastomotic complications in colorectal surgery: a systematic review of techniques for endoscopic salvage

BACKGROUND

Anastomotic complications following colorectal surgery are associated with significant morbidity and mortality. For patients in whom systemic sepsis is absent or well controlled, minimal access techniques, such as endoscopic therapies, are being increasingly employed to reduce the morbidity of surgical re-intervention. In this review, we aim to assess the utility of endoscopic management in the acute setting of colorectal anastomotic complications, focusing on anastomotic leak.

METHOD

A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases using the search criteria string "colorectal anastomotic ("leak" OR "bleed"), "endoscopy", endoscopic management". Additional papers were detected by scanning the references of relevant papers. Data were extracted from each study by two authors onto a dedicated pro-forma. Given the nature of the data extracted, no meta-analysis was performed.

RESULTS

A total of 89 papers were identified, 16 of which were included in this review; an additional 14 papers were obtained from reference searches. In patients who are not physiologically compromised, there are promising data regarding the salvage rate of stents, over-the-scope endoscopic clips, vacuum therapy and fibrin glue in the early management of colorectal anastomotic leak. There is no consensus regarding the optimal approach, and data to assist the physician in patient selection are lacking. Whilst data on salvage (i.e. healing and avoidance of surgery) are well understood, no data on functional outcomes are reported.

CONCLUSION

Endoscopic therapy in the management of stable patients with colorectal anastomotic leaks appears safe and in selected patients is associated with high rates of technical success. Challenges remain in selecting the most appropriate strategy, patient selection, and understanding the functional and long-term sequelae of this approach. Further evidence from large prospective cohort studies are needed to further evaluate the role of these novel strategies.