Has network meta-analysis resolved the controversies related to bowel preparation in elective colorectal surgery?

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.

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.

Leveraging a nationwide infection surveillance program to implement a colorectal surgical site infection reduction bundle: a pragmatic, prospective, and multicenter cohort study

BACKGROUND

Bundled interventions usually reduce surgical site infection (SSI) when implemented at single hospitals, but the feasibility of their implementation at the nationwide level and their clinical results are not well established.

MATERIALS AND METHODS

Pragmatic interventional study to analyze the implementation and outcomes of a colorectal surgery care bundle within a nationwide quality improvement program. The bundle consisted of antibiotic prophylaxis, oral antibiotic prophylaxis (OAP), mechanical bowel preparation, laparoscopy, normothermia, and a wound retractor. Control group (CG) and Intervention group (IG) were compared. Overall SSI, superficial (S-SSI), deep (D-SSI), and organ/space (O/S-SSI) rates were analyzed. Secondary endpoints included microbiology, 30-day mortality, and length of hospital stay.

RESULTS

A total of 37 849 procedures were included, 19 655 in the CG and 18 194 in the IG. In all, 5462 SSIs (14.43%) were detected: 1767 S-SSI (4.67%), 847 D-SSI (2.24%), and 2838 O/S-SSI (7.5%). Overall SSI fell from 18.38% (CG) to 10.17% (IG), odds ratio (OR) of 0.503 [0.473-0.524]. O/S-SSI rates were 9.15% (CG) and 5.72% (IG), OR of 0.602 [0.556-0.652]. The overall SSI rate was 16.71% when no measure was applied and 6.23% when all six were used. Bundle implementation reduced the probability of overall SSI (OR: 0.331; CI 95 : 0.242-0.453), and also O/S-SSI rate (OR: 0.643; CI 95 : 0.416-0.919). In the univariate analysis, all measures except normothermia were associated with a reduction in overall SSI, while only laparoscopy, OAP, and mechanical bowel preparation were related to a decrease in O/S-SSI. Laparoscopy, wound retractor, and OAP decreased overall SSI and O/S-SSI in the multivariate analysis.

CONCLUSIONS

In this cohort study, the application of a specific care bundle within a nationwide nosocomial infection surveillance system proved feasible and resulted in a significant reduction in overall and O/S-SSI rates in the elective colon and rectal surgery. The OR for SSI fell between 1.5 and 3 times after the implementation of the bundle.