[Bowel preparation for elective colorectal surgery in Germany 2017 : Results of a survey among members of the German Society of General and Visceral Surgery]

Morbidity After Mechanical Bowel Preparation and Oral Antibiotics Prior to Rectal Resection: The MOBILE2 Randomized Clinical Trial

Importance

Surgical site infections (SSIs)-especially anastomotic dehiscence-are major contributors to morbidity and mortality after rectal resection. The role of mechanical and oral antibiotics bowel preparation (MOABP) in preventing complications of rectal resection is currently disputed.

Objective

To assess whether MOABP reduces overall complications and SSIs after elective rectal resection compared with mechanical bowel preparation (MBP) plus placebo.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled randomized clinical trial was conducted at 3 university hospitals in Finland between March 18, 2020, and October 10, 2022. Patients aged 18 years and older undergoing elective resection with primary anastomosis of a rectal tumor 15 cm or less from the anal verge on magnetic resonance imaging were eligible for inclusion. Outcomes were analyzed using a modified intention-to-treat principle, which included all patients who were randomly allocated to and underwent elective rectal resection with an anastomosis.

Interventions

Patients were stratified according to tumor distance from the anal verge and neoadjuvant treatment given and randomized in a 1:1 ratio to receive MOABP with an oral regimen of neomycin and metronidazole (n = 277) or MBP plus matching placebo tablets (n = 288). All study medications were taken the day before surgery, and all patients received intravenous antibiotics approximately 30 minutes before surgery.

Main Outcomes and Measures

The primary outcome was overall cumulative postoperative complications measured using the Comprehensive Complication Index. Key secondary outcomes were SSI and anastomotic dehiscence within 30 days after surgery.

Results

In all, 565 patients were included in the analysis, with 288 in the MBP plus placebo group (median [IQR] age, 69 [62-74] years; 190 males [66.0%]) and 277 in the MOABP group (median [IQR] age, 70 [62-75] years; 158 males [57.0%]). Patients in the MOABP group experienced fewer overall postoperative complications (median [IQR] Comprehensive Complication Index, 0 [0-8.66] vs 8.66 [0-20.92]; Wilcoxon effect size, 0.146; P < .001), fewer SSIs (23 patients [8.3%] vs 48 patients [16.7%]; odds ratio, 0.45 [95% CI, 0.27-0.77]), and fewer anastomotic dehiscences (16 patients [5.8%] vs 39 patients [13.5%]; odds ratio, 0.39 [95% CI, 0.21-0.72]) compared with patients in the MBP plus placebo group.

Conclusions and Relevance

Findings of this randomized clinical trial indicate that MOABP reduced overall postoperative complications as well as rates of SSIs and anastomotic dehiscences in patients undergoing elective rectal resection compared with MBP plus placebo. Based on these findings, MOABP should be considered as standard treatment in patients undergoing elective rectal resection.

Trial Registration

ClinicalTrials.gov Identifier: NCT04281667.

Management of Anastomotic Leakage after Colorectal Resection: Survey among the German CHIR-Net Centers

(1) Background: A widely accepted algorithm for the management of colorectal anastomotic leakage (CAL) is difficult to establish. The present study aimed to evaluate the current clinical practice on the management of CAL among the German CHIR-Net centers. (2) Methods: An online survey of 38 questions was prepared using the International Study Group of Rectal Cancer (ISREC) grading score of CAL combined with both patient- and surgery-related factors. All CHIR-Net centers received a link to the online questionary in February 2020. (3) Results: Most of the answering centers (55%) were academic hospitals (41%). Only half of them use the ISREC definition and grading for the management of CAL. A preference towards grade B management (no surgical intervention) of CAL was observed in both young and fit as well as elderly and/or frail patients with deviating ostomy and non-ischemic anastomosis. Elderly and/or frail patients without fecal diversion are generally treated as grade C leakage (surgical intervention). A grade C management of CAL is preferred in case of ischemic bowel, irrespective of the presence of an ostomy. Within grade C management, the intestinal continuity is preserved in a subgroup of patients with non-ischemic bowel, with or without ostomy, or young and fit patients with ischemic bowel under ostomy protection. (4) Conclusions: There is no generally accepted therapy algorithm for CAL management within CHIR-Net Centers in Germany. Further effort should be made to increase the application of the ISREC definition and grading of CAL in clinical practice.

Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery

BACKGROUND

The success of elective colorectal surgery is mainly influenced by the surgical procedure and postoperative complications. The most serious complications include anastomotic leakages and surgical site infections (SSI)s, which can lead to prolonged recovery with impaired long-term health.  Compared with other abdominal procedures, colorectal resections have an increased risk of adverse events due to the physiological bacterial colonisation of the large bowel. Preoperative bowel preparation is used to remove faeces from the bowel lumen and reduce bacterial colonisation. This bowel preparation can be performed mechanically and/or with oral antibiotics. While mechanical bowel preparation alone is not beneficial, the benefits and harms of combined mechanical and oral antibiotic bowel preparation is still unclear.

OBJECTIVES

To assess the evidence for the use of combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and trial registries on 15 December 2021. In addition, we searched reference lists and contacted colorectal surgery organisations.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adult participants undergoing elective colorectal surgery comparing combined mechanical and oral antibiotic bowel preparation (MBP+oAB) with either MBP alone, oAB alone, or no bowel preparation (nBP). We excluded studies in which no perioperative intravenous antibiotic prophylaxis was given.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. Pooled results were reported as mean difference (MD) or risk ratio (RR) and 95 % confidence intervals (CIs) using the Mantel-Haenszel method. The certainty of the evidence was assessed with GRADE.

MAIN RESULTS

We included 21 RCTs analysing 5264 participants who underwent elective colorectal surgery. None of the included studies had a high risk of bias, but two-thirds of the included studies raised some concerns. This was mainly due to the lack of a predefined analysis plan or missing information about the randomisation process. Most included studies investigated both colon and rectal resections due to malignant and benign surgical indications. For MBP as well as oAB, the included studies used different regimens in terms of agent(s), dosage and timing.  Data for all predefined outcomes could be extracted from the included studies. However, only four studies reported on side effects of bowel preparation, and none recorded the occurrence of adverse effects such as dehydration, electrolyte imbalances or the need to discontinue the intervention due to side effects. Seventeen trials compared MBP+oAB with sole MBP. The incidence of SSI could be reduced through MBP+oAB by 44% (RR 0.56, 95% CI 0.42 to 0.74; 3917 participants from 16 studies; moderate-certainty evidence) and the risk of anastomotic leakage could be reduced by 40% (RR 0.60, 95% CI 0.36 to 0.99; 2356 participants from 10 studies; moderate-certainty evidence). No difference between the two comparison groups was found with regard to mortality (RR 0.87, 95% CI 0.27 to 2.82; 639 participants from 3 studies; moderate-certainty evidence), the incidence of postoperative ileus (RR 0.89, 95% CI 0.59 to 1.32; 2013 participants from 6 studies, low-certainty of evidence) and length of hospital stay (MD -0.19, 95% CI -1.81 to 1.44; 621 participants from 3 studies; moderate-certainty evidence). Three trials compared MBP+oAB with sole oAB. No difference was demonstrated between the two treatment alternatives in terms of SSI (RR 0.87, 95% CI 0.34 to 2.21; 960 participants from 3 studies; very low-certainty evidence), anastomotic leakage (RR 0.84, 95% CI 0.21 to 3.45; 960 participants from 3 studies; low-certainty evidence), mortality (RR 1.02, 95% CI 0.30 to 3.50; 709 participants from 2 studies; low-certainty evidence), incidence of postoperative ileus (RR 1.25, 95% CI 0.68 to 2.33; 709 participants from 2 studies; low-certainty evidence) or length of hospital stay (MD 0.1 respectively 0.2, 95% CI -0.68 to 1.08; data from 2 studies; moderate-certainty evidence). One trial (396 participants) compared MBP+oAB versus nBP. The evidence is uncertain about the effect of MBP+oAB on the incidence of SSI as well as mortality (RR 0.63, 95% CI 0.33 to 1.23 respectively RR 0.20, 95% CI 0.01 to 4.22; low-certainty evidence), while no effect on the risk of anastomotic leakages (RR 0.89, 95% CI 0.33 to 2.42; low-certainty evidence), the incidence of postoperative ileus (RR 1.18, 95% CI 0.77 to 1.81; low-certainty evidence) or the length of hospital stay (MD 0.1, 95% CI -0.8 to 1; low-certainty evidence) could be demonstrated.

AUTHORS' CONCLUSIONS

Based on moderate-certainty evidence, our results suggest that MBP+oAB is probably more effective than MBP alone in preventing postoperative complications. In particular, with respect to our primary outcomes, SSI and anastomotic leakage, a lower incidence was demonstrated using MBP+oAB. Whether oAB alone is actually equivalent to MBP+oAB, or leads to a reduction or increase in the risk of postoperative complications, cannot be clarified in light of the low- to very low-certainty evidence. Similarly, it remains unclear whether omitting preoperative bowel preparation leads to an increase in the risk of postoperative complications due to limited evidence. Additional RCTs, particularly on the comparisons of MBP+oAB versus oAB alone or nBP, are needed to assess the impact of oAB alone or nBP compared with MBP+oAB on postoperative complications and to improve confidence in the estimated effect. In addition, RCTs focusing on subgroups (e.g. in relation to type and location of colon resections) or reporting side effects of the intervention are needed to determine the most effective approach of preoperative bowel preparation.

Antibiotic Bowel Decontamination in Gastrointestinal Surgery—A Single-Center 20 Years’ Experience

Objective

Anastomotic leakage, surgical site infections, and other infectious complications are still common complications in gastrointestinal surgery. The concept of perioperative antibiotic bowel decontamination demonstrates beneficial effects in single randomized controlled trials (RCTs), but data from routine clinical use are still sparse. Our aim was to analyze the data from the routine clinical use of perioperative antibiotic bowel decontamination in gastrointestinal surgery.

Methods

Based on 20 years’ experience, we performed a retrospective analysis of all cases in oncologic gastrointestinal surgery with the use of antibiotic bowel decontamination in gastric, sigmoid, and rectal cancer. Clinical data and perioperative outcomes were analyzed, especially regarding anastomotic leakage, surgical site infections, and other infectious complications.

Results

A total of n = 477 cases of gastrointestinal surgery in gastric cancer (n = 80), sigmoid cancer (n = 168), and rectal cancer (n = 229) using a perioperative regimen of antibiotic bowel decontamination could be included in this analysis. Overall, anastomotic leakage occurred in 4.4% (2.5% gastric cancer, 3.0% sigmoid cancer, 6.1% rectal cancer) and surgical site infections in 9.6% (6.3% gastric cancer, 9.5% sigmoid cancer, 10.9% rectal cancer). The incidence of all infectious complications was 13.6% (12.5% gastric cancer, 11.3% sigmoid cancer, 15.7% rectal cancer). Mortality was low, with an overall rate of 1.1% (1.3% gastric cancer, 1.8% sigmoid cancer, 0.4% rectal cancer). Antibiotic decontamination was completed in 98.5%. No adverse effects of antibiotic bowel decontamination could be observed.

Conclusion

Overall, in this large cohort, we can report low rates of surgery-related serious morbidity and mortality when perioperative antibiotic bowel decontamination is performed. The rates are lower than other clinical reports. In our clinical experience, the use of perioperative antibiotic bowel decontamination appears to improve patient safety and surgical outcomes during gastrointestinal oncologic procedures in a routine clinical setting.

Innovative approaches for induction of gastrointestinal anastomotic healing: an update on experimental and clinical aspects

PURPOSE

In most cases, traditional techniques to perform an anastomosis following gastrointestinal resections lead to successful healing. However, despite focused research in the field, in certain high-risk situations leakage rates remain almost unchanged. Here, additional techniques may help the surgeon to protect the anastomosis and prevent leakage. We give an overview of some of the latest developments on experimental and clinical techniques for induction of anastomotic healing.

METHODS

We performed a review of the current literature on approaches to improve anastomotic healing.

RESULTS

Many promising approaches with a high clinical potential are in the developmental pipeline. Highly experimental approaches like inhibition of matrix metalloproteinases, stem cell therapy, hyperbaric oxygen therapy, induction of the hypoxic adaptive response, and the administration of growth factors are still in the preclinical phase. Other more clinical developments aim to strengthen the anastomotic suture line mechanically while shielding it from the influence of the microbiome. Among them are gluing, seaming the staple line, attachment of laminar biomaterials, and temporary intraluminal tubes. In addition, individualized bowel preparation, selectively reducing certain detrimental microbial populations could become the next stage of bowel preparation. Compression anastomoses are evolving as an equivalent technique additional to established hand-sewn and stapled anastomoses. Fluorescence angiography and flexible endoscopy could complement intraoperative quality control additionally to the air leak tests. Virtual ileostomy is a concept to prepare the bowel for the easy formation of a stoma in case of leakage.

CONCLUSION

A variety of promising diagnostic and prophylactic measures that may support the surgeon in identifying high-risk anastomoses and support them according to their potential deficits is currently in development.

How to reduce anastomotic leakage in colorectal surgery-report from German expert meeting

AIMS

Anastomotic leakage is one of the most worrisome complications in colorectal surgery. An expert meeting was organized to discuss and find a consensus on various aspects of the surgical management of colorectal disease with a possible impact on anastomotic leakage.

METHODS

A three-step Delphi-method was used to find consensus recommendations.

RESULTS

Strong consensus was achieved for the use of mechanical bowel preparation and oral antibiotics prior to colorectal resections, the abundance of non-selective NSAIDs, the preoperative treatment of severe iron deficiency anemia, and for attempting to improve the patients' general performance in the case of frailty. Concerning technical aspects of rectal resection, there was a strong consensus in regard to routinely mobilizing the splenic flexure, to dividing the inferior mesenteric vein, and to using air leak tests to check anastomotic integrity. There was also a strong consensus on not to oversew the stapled anastomoses routinely, to use protective ileostomies for low rectal and intersphincteric, but not for high-rectal anastomoses. Furthermore, a consensus was reached in regard to using CT-scans with rectal contrast enema to evaluate suspected anastomotic leakage as well as measuring C-reactive protein routinely to monitor the postoperative course after colorectal resections. No consensus was found concerning the indication and technique for testing bowel perfusion, the routine use of endoscopy to check the integrity of the anastomosis, the placement of transanal drains for rectal anastomoses and the management of anastomotic leakage with peritonitis.

CONCLUSION

Consensus could be found for several practice details in the perioperative management in colorectal surgery that might have an influence on anastomotic leakage.

[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.

[Preoperative bowel conditioning]

BACKGROUND

Gastrointestinal surgery is still associated with a relevant morbidity with the intestinal microbiome being of high importance in the pathogenesis of infectious complications. Various approaches, such as mechanical bowel preparation (MBP) with or without administration of oral antibiotics, fasting or dietary supplements aim at modulating the intestinal flora.

OBJECTIVE

This review summarizes the current literature pertinent to the influence of preoperative bowel conditioning on postoperative morbidity.

MATERIAL AND METHODS

A literature search was performed using the mentioned keywords with a focus on recent meta-analyses.

RESULTS AND CONCLUSION

Bowel conditioning reduces postoperative infectious complications. Promising approaches are MBP plus administration of oral antibiotics, dietary supplements aiming at stabilization of the intestinal flora as well as the screening for and equilibration of malnutrition. The use of MBP as monotherapy without antibiotics should no longer be considered part of the clinical routine.