Prevention of anastomotic leak in rectal cancer surgery with local antibiotic decontamination: a prospective, randomized, double-blind, placebo-controlled single center trial

Bacterial shift and resistance pattern in pancreatic head resections after selective decontamination of the digestive tract - a propensity score-matched analysis

BACKGROUND

Pancreatic head resection is associated with postoperative morbidity, primarily because of infectious complications. The microbiota in these infections is crucial, and selective decontamination of the digestive tract (SDD) aims to mitigate this risk by targeting pathogenic organisms while preserving beneficial flora. This study aimed to determine the effect of SDD on bacterial shifts and resistance patterns in pancreatic head resection.

METHODS

All patients who underwent pancreatic head resection either between January 2012 and August 2018 (non-SDD group) or between January 2019 and December 2021 (SDD group) were included. Propensity score-matched analysis was performed to compare the bacterial presence and resistance patterns in bile duct smear tests and postoperative complications.

RESULTS

Positive bile duct smear tests were observed more often in the non-SDD group (63.5%) than in the SDD group (51.0%). Moreover, the SDD group exhibited a significant reduction in the median number of bacterial species in the bile ducts compared with the non-SDD group (P = .04). However, a notable increase in gram-negative species was observed in the SDD group. The SDD group experienced higher rates of postoperative complications, including relevant pancreatic fistulas (24.8% in the SDD group vs 11.6% in the non-SDD group; P < .01) and delayed gastric emptying (33.8% in the SDD group vs 21.9% in the non-SDD group; P < .01). No significant difference in antibiotic resistance patterns was observed.

CONCLUSION

SDD in pancreatic head resection reduces bacterial load in the biliary tract, but it is associated with a shift toward more gram-negative species and higher rates of severe postoperative complications. Our findings suggest that SDD may negatively affect postoperative outcomes and should be carefully considered in clinical practice.

Outcome of a 3-day vs 7-day selective digestive tract decontamination-based regimen for oral antibiotic bowel decontamination in left-sided colorectal surgery: A noninferiority study

BACKGROUND

Colorectal surgery still experiences high rates of infectious complications, such as anastomotic leakage (AL) and surgical site infections (SSIs). Therefore, oral antibiotic bowel decontamination (OABD) has experienced a renaissance. However, data on perioperative selective digestive tract decontamination (SDD)-based regimens or combined bowel preparation are inconsistent. Nonetheless, with widespread use of Enhanced Recovery After Surgery concepts, the ideal length for perioperative SDD treatment has to be reconsidered.

METHODS

Perioperative outcome was analyzed in a cohort of patients undergoing minimally invasive surgery for left-sided colorectal cancer in a retrospective study. Additional to usual perioperative outcome measures, including AL, SSIs, and overall infectious complications, the efficacy of a shortened 3-day perioperative OABD treatment was compared with the efficacy of a 7-day perioperative OABD treatment based on a noninferiority analysis.

RESULTS

Overall, 256 patients were included into analysis, of whom 84 and 172 patients were treated by 3-day and 7-day perioperative OABD regimens, respectively. AL occurred in 1.2% of patients in the 3-day group and 5.2% of patients in the 7-day group, and SSIs occurred in 3.6% of patients in the 3-day group and 5.8% of patients in the 7-day group, without significant difference. The shortened 3-day perioperative SDD-based regimen was noninferior to the regular 7-day perioperative SDD-based regimen concerning the rates of AL, SSIs, and infectious complications.

CONCLUSION

Our data demonstrated noninferiority of a shortened 3-day SDD-based treatment vs a 7-day SDD-based treatment for AL, SSIs, and overall infectious complications.

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.

Successful Clinical Avoidance of Colorectal Anastomotic Leakage through Local Decontamination

AIM

An anastomotic leak is an unpredictable postoperative complication during recovery from colorectal surgery that may require a re-operation. Potentially pathogenic bacteria like Pseudomonas (and Enterococcus) contribute to the pathogenesis of an anastomotic leak through their capacity to degrade collagen and to activate tissue matrix metalloprotease-9 in host intestinal tissues. The microbiome, therefore, is the key to preventing an anastomotic leak after colorectal surgery. The aim of this trial was to investigate whether perioperative selective decontamination with a new mixture of locally acting antibiotics specially designed against Pseudomonas aeruginosa and Enterococcus faecalis can reduce or even stop early symptomatic leakage.

METHOD

All hospitalized patients in our University Clinic undergoing colorectal surgery with a left-sided anastomosis were included as two groups; patients in the intervention group received polymyxin B, gentamicin and vancomycin every six hours for five postoperative days and those in the control group did not receive such an intervention. An anastomotic leak was defined as a clinically obvious defect of the intestinal wall integrity at the colorectal anastomosis site (including suture) that leads to a communication between the intra- and extraluminal compartments, requiring a re-do surgery within seven postoperative days.

RESULTS

Between February 2017 and May 2023, a total of 301 patients (median age of 63 years) were analyzed. An anastomotic leak was observed in 11 patients in the control group (n = 152), but in no patients in the intervention group (n = 149); this difference was highly significant.

CONCLUSION

The antibiotic mixture (with polymyxin B, gentamicin and vancomycin) used for local decontamination in our study stopped the occurrence of anastomotic leaks completely. According to the definition of anastomotic leak, no further surgery was required after local perioperative decontamination.

Validation of an endoscopic anastomotic grading score as an intraoperative method for assessing stapled rectal anastomoses

PURPOSE

Anastomotic leak is a dreaded complication of colorectal surgery. An endoscopic grading score of the perianastomotic mucosa has been previously developed at our institution (UCI) to assess colorectal anastomotic integrity. The objective of this study is to validate the UCI anastomotic score and determine its impact in anastomotic failure.

METHODS

As a follow-up study of the UCI grading score implementation during 2011 to 2014, patients undergoing stapled colorectal anastomoses after sigmoidectomy or proctectomy at a single institution from 2015 to 2018 were retrospectively reviewed. Patients were grouped into three tiers based on endoscopic appearance (grade 1, circumferentially normal mucosa; grade 2, ischemia/congestion < 30% of circumference; grade 3, ischemia/congestion > 30% of circumference).

RESULTS

On the basis of endoscopic mucosal evaluation, grade 1 anastomosis was observed in 299 patients (94%), grade 2 anastomosis in 14 patients (4.4%), and grade 3 anastomosis in 5 patients (1.6%). All grade 3 classifications were immediately and successfully revised intraoperatively with reclassification as a grade 1 anastomosis. The anastomotic leak rate of the follow-up study period from 2015 to 2018 was 6.4% which was lower compared to the anastomotic leak rate of 12.2% in the original study period from 2011 to 2014 (p = 0.07). Anastomotic leak rate for the entire patient series was 8.5%. A grade 2 anastomosis was associated with higher anastomotic leak rate compared to a grade 1 anastomosis (35.7% vs. 7.4%, p < 0.05). None of the five grade 3 anastomoses resulted in an anastomotic leak upon revision.

CONCLUSION

This study further validates the anastomotic grading score and suggests that its systematic implementation can result in a reduction in anastomotic leaks.

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.

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.

Mechanical bowel preparation combined with oral antibiotics reduces infectious complications and anastomotic leak in elective colorectal surgery: a pooled-analysis with trial sequential analysis

OBJECTIVE

A pooled analysis combined with trial sequential analysis (TSA) was conducted in order to explore the effect of mechanical bowel preparation (MBP) combined with oral antibiotic bowel decontamination (OAB) versus MBP alone on patients who have undergone colorectal resection.

METHODS

Comprehensive and systematic searches of PubMed, Embase, Cochrane Library, Web of Knowledge, and Clinical Trials.gov databases were conducted. The quality of literature was evaluated using Cochrane risk bias assessment tool as well as Newcastle-Ottawa Scale (NOS) score. A pooled analysis of randomized controlled trials (RCTs) and prospective studies was performed comparing patients who underwent colorectal resection and received MBP plus OAB or MBP alone. The outcome endpoints were the incidence of anastomotic leak (AL) and surgical site infection (SSI). TSA is a tool used to assess the reliability of currently available evidence to determine further clinical trial validation.

RESULTS

The analysis included a total of 22 studies involving 8852 patients, including 3016 patients in the MBP + OAB group and 4415 patients exposed to MBP alone. The pooled analysis showed that the incidence of postoperative anastomotic leak was significantly lower in the group treated with MBP plus OAB compared with MBP alone (OR = 0.43, 95% CI: 0.23-0.81, P = 0.009, I2 = 73%). The incidence of postoperative surgical site infections was significantly lower in the group exposed to the combination of MBP and OAB compared with MBP alone (OR = 0.38, 95% CI: 0.32-0.46, P < 0.0001, I2 = 24%). The TSA demonstrated significant benefits of MBP plus OAB intervention in terms of AL and SSI.

CONCLUSION

MBP combined with OAB significantly reduces the incidence of AL and SSI in patients after colorectal resection compared with MBP alone.

Selective Decontamination of the Digestive Tract in Pancreatic Head Resections-A Propensity Score-Matched Analysis

(1) Background: The postoperative morbidity rate after pancreatic head resection remains high, partly due to infectious complications. The primary aim of this study was to analyze the influence of selective decontamination of the digestive tract (SDD) on the postoperative infection rate after pancreatic surgery. (2) Methods: From January 2019, the standard of care for patients undergoing pancreatic head resections at the Department for Visceral, Thoracic, and Vascular Surgery, University Hospital Dresden was the preoperative oral administration of SDD. The influence of SDD was evaluated for patients operated on between January 2019 and June 2020 in comparison to a propensity score-matched cohort, extracted from an existing database including all pancreatic resections from 2012 to 2018. The primary endpoint of the study was the shift of the bacterial load on the intraoperative bile swab test. The secondary endpoint was the association of SDD with postoperative complications. (3) Results: In total, 200 patients either with SDD (n = 100; 50%) or without SDD (non-SDD, n = 100; 50%) were analyzed. In the patient group without a preoperative biliary stent, 44% (n = 11) of the non-SDD group displayed positive bacterial results, whereas that was the case for only 21.7% (n = 10) in the SDD group (p = 0.05). Particularly, Enterobacter species (spp.) were reduced from 41.2% (n = 14) (non-SDD group) to 23.5% (n = 12) (SDD group) (p = 0.08), and Citrobacter spp. were reduced by 13.7% (p = 0.09) from the non-SDD to the SDD cohort. In patients with a preoperative biliary stent, the Gram-negative Enterobacter spp. were significantly reduced from 52.2% (n = 12) in the non-SDD group to 26.8% (n = 11) in the SDD group (p = 0.04). Similarly, Citrobacter spp. decreased by 20.6% from 30.4% (n = 7) to 9.8% (n = 4) in the non-SDD compared to the SDD group (p = 0.04). In general, deep fluid collection and abscesses occurred more frequently in the non-SDD group (36%; n = 36 vs. 27%; n = 27; p = 0.17). (4) Conclusions: Adoption of SDD before pancreatic head surgery may reduce the bacterial load in bile fluid. SDD administration does not significantly affect the postoperative infectious complication rate after pancreatic head resections.

Anastomotic leakage in rectal cancer surgery: Retrospective analysis of risk factors

BACKGROUND

Anastomotic leakage (AL) after restorative surgery for rectal cancer (RC) is associated with significant morbidity and mortality.

AIM

To ascertain the risk factors by examining cases of AL in rectal surgery in this retrospective cohort study.

METHODS

To identify risk factors for AL, a review of 583 patients who underwent rectal resection with a double-stapling colorectal anastomosis between January 2007 and January 2022 was performed. Clinical, demographic and operative features, intraoperative outcomes and oncological characteristics were evaluated.

RESULTS

The incidence of AL was 10.4%, with a mean time interval of 6.2 ± 2.1 d. Overall mortality was 0.8%. Mortality was higher in patients with AL (4.9%) than in patients without leak (0.4%, P = 0.009). Poor bowel preparation, blood transfusion, median age, prognostic nutritional index < 40 points, tumor diameter and intraoperative blood loss were identified as risk factors for AL. Location of anastomosis, number of stapler cartridges used to divide the rectum, diameter of circular stapler, level of vascular section, T and N status and stage of disease were also correlated to AL in our patients. The diverting ileostomy did not reduce the leak rate, while the use of the transanastomic tube significantly did.

CONCLUSION

Clinical, surgical and pathological factors are associated with an increased risk of AL. It adversely affects the morbidity and mortality of RC patients.

Mechanical bowel preparation with or without oral antibiotics for rectal resection for cancer (REPCA trial): a study protocol for a multicenter randomized controlled trial

BACKGROUND

There is still a lack of randomized trials assessing the clinical value of mechanical bowel preparation (MBP) and oral antibiotics (OA) before rectal surgery. Existing studies are inconsistent regarding OA. The aim of this study is to examine the role of MBP with or without OA (using Alfa Normix^®) on postoperative complications in patients undergoing rectal resection for cancer.

METHODS

We are conducting a prospective multicenter randomized controlled trial comparing MBP (Moviprep^®) with OA (Alfa Normix^®) versus MBP alone in patients undergoing elective rectal resection for cancer. Patients with rectal or rectosigmoid cancer are randomized in a 1:1 allocation ratio. The primary endpoint is incisional surgical site infection (SSI) assessed within 30 days after surgery. Secondary endpoints are anastomotic leakage (AL), organ/space SSI, other postoperative complications, intraoperative complications, operation time, bowel preparation quality, bowel preparation adherence. Intention-to-treat and per protocol analyses will be performed.

CONCLUSIONS

The results of the REPCA trial will demonstrate whether MBP + OA is superior to MBP alone in rectal cancer surgery. This trial might influence current preoperative practice and improve postoperative outcomes.

A Network Meta-Analysis and GRADE Assessment of the Effect of Preoperative Oral Antibiotics with and Without Mechanical Bowel Preparation on Surgical Site Infection Rate in Colorectal Surgery

Objective

To compare the effect of different methods of bowel preparation on the incidence of surgical site infections (SSI), anastomotic leakage (AL), and mortality in patients undergoing elective colorectal surgery.

Background

Recent guidelines advise mechanical bowel preparation with oral antibiotics (MBP-OA) for the prevention of SSI in colorectal surgery. Recent trials suggest oral antibiotics (OA) alone may be sufficient.

Methods

PubMed, MEDLINE, and Embase were searched from inception until 10-08-2021. We included randomized controlled trials (RCTs) comparing multiple methods of bowel preparation (mechanical bowel preparation [MBP], OA, MBP-OA, or no preparation) with regards to clinical outcomes such as incidence of SSI, AL, and mortality rates. A frequentist random-effects network meta-analysis was conducted to estimate the network effects of the different treatment options.

Results

We included 48 studies with 13,611 patients. Compared to no preparation, combined direct and indirect network estimates showed a relative risk (RR) for SSI of 0.57 (95% confidence interval [CI], 0.45-0.72) for MBP-OA, 0.68 (95% CI, 0.49-0.95) for OA, and 1.05 (95% CI, 0.87-1.26) for MBP. The RR for MBP-OA compared to OA was 0.84 (95% CI, 0.60-1.19); in sensitivity analysis of mainly laparoscopic procedures this effect of MBP-OA was more profound (RR, 0.56; 95% CI, 0.31-0.99).

Conclusions

This network meta-analysis of RCTs finds that both mechanical bowel preparation with oral antibiotics and oral antibiotics alone are comparably effective in the prevention of SSI. The evidence is uncertain about the relative benefit of MBP-OA compared to OA alone. Therefore, it seems justified to use either of the 2 for the prevention of SSI in colorectal surgery.

Metronidazole Delivery Nanosystem Able To Reduce the Pathogenicity of Bacteria in Colorectal Infection

Metronidazole (MTZ) is a drug potentially used for the treatment of intestinal infections, namely, the ones caused by colorectal surgery. The traditional routes of administration decrease its local effectiveness and present off-site effects. To circumvent such limitations, herein a drug delivery system (DDS) based on MTZ-loaded nanoparticles (NPs) immobilized at the surface of electrospun fibrous meshes is proposed. MTZ at different concentrations (1, 2, 5, and 10 mg mL^-1) was loaded into chitosan-sodium tripolyphosphate NPs. The MTZ loaded into NPs at the highest concentration showed a quick release in the first 12 h, followed by a gradual release. This DDS was not toxic to human colonic cells. When tested against different bacterial strains, a significant reduction of Escherichia coli and Staphylococcus aureus was observed, but no effect was found against Enterococcus faecalis. Therefore, this DDS offers high potential to locally prevent the occurrence of infections after colorectal anastomosis.

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.

Selective decontamination of the digestive tract in colorectal surgery reduces anastomotic leakage and costs: a propensity score analysis

Purpose

Anastomotic leakage (AL) and surgical site infection (SSI) account for most postoperative complications in colorectal surgery. The aim of this retrospective trial was to investigate whether perioperative selective decontamination of the digestive tract (SDD) reduces these complications and to provide a cost-effectiveness model for elective colorectal surgery.

Methods

All patients operated between November 2016 and March 2020 were included in our analysis. Patients in the primary cohort (PC) received SDD and those in the historical control cohort (CC) did not receive SDD. In the case of rectal/sigmoid resection, SDD was also applied via a transanally placed Foley catheter (TAFC) for 48 h postoperatively. A propensity score-matched analysis was performed to identify risk factors for AL and SSI. Costs were calculated based on German diagnosis-related group (DRG) fees per case.

Results

A total of 308 patients (154 per cohort) with a median age of 62.6 years (IQR 52.5–70.8) were analyzed. AL was observed in ten patients (6.5%) in the PC and 23 patients (14.9%) in the CC (OR 0.380, 95% CI 0.174–0.833; P = 0.016). SSI occurred in 14 patients (9.1%) in the PC and 30 patients in the CC (19.5%), representing a significant reduction in our SSI rate (P = 0.009). The cost-effectiveness analysis showed that SDD is highly effective in saving costs with a number needed to treat of 12 for AL and 10 for SSI.

Conclusion

SDD significantly reduces the incidence of AL and SSI and saves costs for the general healthcare system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-022-02540-6.

Anastomotic leakage in colorectal cancer surgery

The safety of colorectal surgery for oncological disease is steadily improving, but anastomotic leakage is still the most feared and devastating complication from both a surgical and oncological point of view. Anastomotic leakage affects the outcome of the surgery, increases the times and costs of hospitalization, and worsens the prognosis in terms of short- and long-term outcomes. Anastomotic leakage has a wide range of clinical features ranging from radiological only finding to peritonitis and sepsis with multi-organ failure. C-reactive protein and procalcitonin have been identified as early predictors of anastomotic leakage starting from postoperative day 2-3, but abdominal-pelvic computed tomography scan is still the gold standard for the diagnosis. Several treatments can be adopted for anastomotic leakage. However, there is not a universally accepted flowchart for the management, which should be individualized based on patient's general condition, anastomotic defect size and location, indication for primary resection and presence of the proximal stoma. Non-operative management is usually preferred in patients who underwent proximal faecal diversion at the initial operation. Laparoscopy can be attempted after minimal invasive surgery and can reduce surgical stress in patients allowing a definitive treatment. Reoperation for sepsis control is rarely necessary in those patients who already have a diverting stoma at the time of the leak, especially in extraperitoneal anastomoses. In patients without a stoma who do not require abdominal reoperation for a contained pelvic leak, there are several treatment options, including laparoscopic diverting ileostomy combined with trans-anal anastomotic tube drainage, percutaneous drainage or recently developed endoscopic procedures, such as stent or clip placement or endoluminal vacuum-assisted therapy. We describe the current approaches to treat this complication, as well as the clinical tests necessary to diagnose and provide an effective therapy.

Oral and Parenteral vs. Parenteral Antibiotic Prophylaxis for Patients Undergoing Laparoscopic Colorectal Resection: An Intervention Review with Meta-Analysis

This study aims to systematically assess the efficacy of parenteral and oral antibiotic prophylaxis compared to parenteral-only prophylaxis for the prevention of surgical site infection (SSI) in patients undergoing laparoscopic surgery for colorectal cancer resection. Published and unpublished randomized clinical trials comparing the use of oral and parenteral prophylactic antibiotics vs. parenteral-only antibiotics in patients undergoing laparoscopic colorectal surgery were collected searching electronic databases (MEDLINE, CENTRAL, EMBASE, SCIENCE CITATION INDEX EXPANDED) without limits of date, language, or any other search filter. The outcomes included SSIs and other infectious and noninfectious postoperative complications. Risk of bias was assessed using the Cochrane revised tool for assessing risk of bias in randomized trials (RoB 2). A total of six studies involving 2252 patients were finally included, with 1126 cases in the oral and parenteral group and 1126 cases in the parenteral-only group. Meta-analysis results showed a statistically significant reduction of SSIs (OR 0.54, 95% CI 0.40 to 0.72; p < 0.0001) and anastomotic leakage (OR 0.55, 95% CI 0.33 to 0.91; p = 0.02) in the group of patients receiving oral antibiotics in addition to intravenous (IV) antibiotics compared to IV alone. Our meta-analysis shows that a combination of oral antibiotics and intravenous antibiotics significantly lowers the incidence of SSI compared with intravenous antibiotics alone.

Anastomotic Leak: Toward an Understanding of Its Root Causes

BACKGROUND

When an anastomotic leak is discussed at a typical surgical morbidity and mortality conference, it is often presented as a due to an error in surgical technique involving ischemia, tension, or device failure. Here we assert that without direct visual analysis of the leak site and its tissue histology, an ex post facto claim that an anastomotic leak is due to an error in surgical technique remains speculative.

METHODS

The arguments and rationale used to conclude that an anastomotic leak is due to an error in surgical technique are critically reviewed and assessed for their validity.

RESULTS

No case series or literature exists in which a root cause analysis has been carried out with visual and tissue level evidence to determine the root cause(s) of an anastomotic leak.

CONCLUSIONS

At the individual case level, declaring that an anastomotic leak is due to an error in surgical technique without clear and compelling evidence either visually and/or at the tissue level to substantiate such a claim remains speculative.

Oral Antibiotic Prophylaxis Reduces Surgical Site Infection and Anastomotic Leakage in Patients Undergoing Colorectal Cancer Surgery

BACKGROUND

Surgical-site infection (SSI) and anastomotic leakage (AL) are major complications following surgical resection of colorectal carcinoma (CRC). The beneficial effect of prophylactic oral antibiotics (OABs) on AL in particular is inconsistent. We investigated the impact of OABs on AL rates and on SSI.

METHODS

A systematic review and meta-analysis of recent RCTs and cohort studies was performed including patients undergoing elective CRC surgery, receiving OABs with or without mechanical bowel preparation (MBP). Primary outcomes were rates of SSI and AL. Secondarily, rates of SSI and AL were compared in broad-spectrum OABs and selective OABs (selective decontamination of the digestive tract (SDD)) subgroups.

RESULTS

Eight studies (seven RCTs and one cohort study) with a total of 2497 patients were included. Oral antibiotics combined with MBP was associated with a significant reduction in SSI (RR = 0.46, 95% confidence interval (CI) 0.31-0.69), I² = 1.03%) and AL rates (RR = 0.58, 95% CI 0.37-0.91, I² = 0.00%), compared to MBP alone. A subgroup analysis demonstrated that SDD resulted in a significant reduction in AL rates compared to broad-spectrum OABs (RR = 0.52, 95% CI 0.30 to 0.91), I² = 0.00%).

CONCLUSION

OABs in addition to MBP reduces SSI and AL rates in patients undergoing elective CRC surgery and, more specifically, SDD appears to be more effective compared to broad-spectrum OABs in reducing AL.

Mucosa plication reinforced colorectal anastomosis and trans-anal vacuum drainage: a pilot study with preliminary results

Dehiscence of colorectal anastomosis is a serious complication that is associated with increased mortality, impaired functional and oncological outcomes. The hypothesis was that anastomosis reinforcement and vacuum trans-anal drainage could eliminate some risk factors, such as mechanically stapled anastomosis instability and local infection. Patients with rectal cancer within 10 cm of the anal verge and low anterior resection with double-stapled technique were included consecutively. A stapler anastomosis was supplemented by trans-anal reinforcement and vacuum drainage using a povidone-iodine-soaked sponge. Modified reinforcement using a circular mucosa plication was developed and used. Patients were followed up by postoperative endoscopy and outcomes were acute leak rate, morbidity, and diversion rate. The procedure was successfully completed in 52 from 54 patients during time period January 2019–October 2020. The mean age of patients was 61 years (lower–upper quartiles 54–69 years). There were 38/52 (73%) males and 14/52 (27%) females; the neoadjuvant radiotherapy was indicated in a group of patients in 24/52 (46%). The mean level of anastomosis was 3.8 cm (lower–upper quartiles 3.00–4.88 cm). The overall morbidity was 32.6% (17/52) and Clavien–Dindo complications ≥ 3 grade appeared in 3/52 (5.7%) patients. No loss of anastomosis was recorded and no patient died postoperatively. The symptomatic anastomotic leak was recorded in 2 (3.8%) patients and asymptomatic blind fistula was recorded in one patient 1/52 (1.9%). Diversion ileostomy was created in 1/52 patient (1.9%). Reinforcement of double-stapled anastomosis using a circular mucosa plication with combination of vacuum povidone-iodine-soaked sponge drainage led to a low acute leak and diversion rate. This pilot study requires further investigation.

Registered at ClinicalTrials.gov.: Trial registration number is NCT04735107, date of registration February 2, 2021, registered retrospectively.

The gut microbiota and colorectal surgery outcomes: facts or hype? A narrative review

BACKGROUND

The gut microbiota (GM) has been proposed as one of the main determinants of colorectal surgery complications and theorized as the "missing factor" that could explain still poorly understood complications. Herein, we investigate this theory and report the current evidence on the role of the GM in colorectal surgery.

METHODS

We first present the findings associating the role of the GM with the physiological response to surgery. Second, the change in GM composition during and after surgery and its association with colorectal surgery complications (ileus, adhesions, surgical-site infections, anastomotic leak, and diversion colitis) are reviewed. Finally, we present the findings linking GM science to the application of the enhanced recovery after surgery (ERAS) protocol, for the use of oral antibiotics with mechanical bowel preparation and for the administration of probiotics/synbiotics.

RESULTS

According to preclinical and translational evidence, the GM is capable of influencing colorectal surgery outcomes. Clinical evidence supports the application of an ERAS protocol and the preoperative administration of multistrain probiotics/synbiotics. GM manipulation with oral antibiotics with mechanical bowel preparation still has uncertain benefits in right-sided colic resection but is very promising for left-sided colic resection.

CONCLUSIONS

The GM may be a determinant of colorectal surgery outcomes. There is an emerging need to implement translational research on the topic. Future clinical studies should clarify the composition of preoperative and postoperative GM and the impact of the GM on different colorectal surgery complications and should assess the validity of GM-targeted measures in effectively reducing complications for all colorectal surgery locations.

Oral antibiotic bowel decontamination in open and laparoscopic sigmoid resections for diverticular disease

PURPOSE

There is an ongoing debate on whether or not to use oral antibiotic bowel decontamination in colorectal surgery, despite the numerous different regimens in terms of antibiotic substances and duration of application. As we routinely use oral antibiotic bowel decontamination (selective decontamination of the digestive tract (SDD) regimen and SDD regimen plus vancomycin since 2016) in surgery for diverticular disease, our aim was to retrospectively analyze the perioperative outcome in two independent centers.

METHODS

Data from two centers with a routine use of oral antibiotic bowel decontamination for up to 20 years of experience were analyzed for the perioperative outcome of 384 patients undergoing surgery for diverticular disease.

RESULTS

Overall morbidity was 12.8%, overall mortality was 0.3%, the overall rate of anastomotic leakage (AL) was 1.0%, and surgical site infections (SSIs) were 5.5% and 7.8% of all infectious complications including urinary tract infections and pneumonia. No serious adverse events were related to use of oral antibiotic bowel decontamination. Most of the patients (93.8%) completed the perioperative regimen. Additional use of vancomycin to the SDD regimen did not show a further reduction of infectious complications, including SSI and AL.

CONCLUSION

Oral antibiotic decontamination appears to be safe and effective with low rates of AL and infectious complications in surgery for diverticular disease.

Mechanical plus oral bowel preparation with paromomycin and metronidazole reduces infectious complications in elective colorectal surgery: a matched case-control study

PURPOSE

Infectious complications are as high as 30% in elective colorectal surgery. In recent years, several studies have discussed the topic of preoperative bowel decontamination prior to colorectal surgery in order to reduce postoperative infectious complications and have found significant effects of oral antibiotic administration with a large variety of drugs used. No study has evaluated the combination of oral paromomycin and metronidazole in this context.

METHODS

We performed a prospective single-center study with a matched-pair retrospective cohort to evaluate postoperative infectious complications (superficial site infections, organ space abscess, anastomotic leakage) in elective colorectal surgery.

PATIENTS

A total of 120 patients were available for study inclusion; 101 gave informed consent and were included. A total of 92 patients were matched and subsequently analyzed. We could show a reduction in overall infectious complications in the intervention group (15.2% vs 30.8%, p = 0.018; odds ratio 0.333, 95% CI 0.142-0.784) as well as a reduction in superficial surgical site infections (8.7 vs 19.6%, p = 0.041, OR 0.333, 95% CI 0.121-0.917). The frequency of the other infectious complications such as intraabdominal abscesses and anastomotic leakage showed a tendency towards decreased frequencies in the intervention group (OR 0.714, 95% CI 0.235-2.169 and OR 0.571; 95% CI 0.167-1.952, respectively). Finally, the oral antibiotic administration led to an almost significantly reduced length of stay (12.24 days vs 15.25 days; p = 0.057).

CONCLUSIONS

Oral paromomycin and metronidazole with intravenous ertapenem effectively reduce infectious complications in elective colorectal surgery.

TRIAL REGISTRATION

The study was registered at Clinicaltrials.gov (NCT03759886) December 17, 2018.