Management Strategies for Malignant Left-Sided Colonic Obstruction: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials and Propensity Score Matching Studies.

BACKGROUND: The optimal treatment strategy for left-sided malignant colonic obstruction remains controversial. Emergency colonic resection has been the standard of care; however, self-expanding metallic stenting as a bridge to surgery may offer short-term advantages, although oncological concerns exist. Decompressing stoma may provide a valid alternative, with limited evidence. OBJECTIVE: To perform a systematic review and Bayesian arm random-effects model network meta-analysis comparing the approaches for management of malignant left-sided colonic obstruction. DATA SOURCES: A systematic review of PubMed, Embase, Cochrane Library, and Google Scholar databases was conducted from inception to August 22, 2023. STUDY SELECTION: Randomized controlled trials and propensity score-matched studies. INTERVENTIONS: Emergency colonic resection, self-expanding metallic stent, and decompressing stoma. MAIN OUTCOME MEASURES: Oncologic efficacy, morbidity, successful minimally invasive surgery, primary anastomosis, and permanent stoma rates. RESULTS: Nineteen of 5225 articles identified met our inclusion criteria. Stenting (risk ratio 0.57; 95% credible interval, 0.33-0.79) and decompressing stomas (risk ratio 0.46, 95% credible interval: 0.18-0.92) resulted in a significant reduction in the permanent stoma rate. Stenting facilitated minimally invasive surgery more frequently (risk ratio 4.10; 95% credible interval, 1.45-13.13) and had lower overall morbidity (risk ratio 0.58; 95% credible interval, 0.35-0.86). A pairwise analysis of primary anastomosis rates showed increased stenting (risk ratio 1.40; 95% credible interval, 1.31-1.49) compared with emergency resection. There was a significant decrease in the 90-day mortality with stenting (risk ratio 0.63; 95% credible interval, 0.41-0.95) compared with resection. There were no differences in disease-free and overall survival rates, respectively. LIMITATIONS: There is a lack of randomized controlled trials and propensity score matching data comparing short-term and long-term outcomes for diverting stomas compared to self-expanding metallic stents. Two trials compared self-expanding metallic stents and diverting stomas in left-sided malignant colonic obstruction. CONCLUSIONS: This study provides high-level evidence that a bridge-to-surgery strategy is safe for the management of left-sided malignant colonic obstruction and may facilitate minimally invasive surgery, increase primary anastomosis rates, and reduce permanent stoma rates and postoperative morbidity compared with emergency colonic resection.

Mechanical bowel preparation and antibiotics in elective colorectal surgery: network meta-analysis.

BACKGROUND: The use of intravenous antibiotics at anaesthetic induction in colorectal surgery is the standard of care. However, the role of mechanical bowel preparation, enemas, and oral antibiotics in surgical site infection, anastomotic leak, and other perioperative outcomes remains controversial. The aim of this study was to determine the optimal preoperative bowel preparation strategy in elective colorectal surgery. METHODS: A systematic review and network meta-analysis of RCTs was performed with searches from PubMed/MEDLINE, Scopus, Embase, and the Cochrane Central Register of Controlled Trials from inception to December 2022. Primary outcomes included surgical site infection and anastomotic leak. Secondary outcomes included 30-day mortality rate, ileus, length of stay, return to theatre, other infections, and side effects of antibiotic therapy or bowel preparation. RESULTS: Sixty RCTs involving 16 314 patients were included in the final analysis: 3465 (21.2 per cent) had intravenous antibiotics alone, 5268 (32.3 per cent) had intravenous antibiotics + mechanical bowel preparation, 1710 (10.5 per cent) had intravenous antibiotics + oral antibiotics, 4183 (25.6 per cent) had intravenous antibiotics + oral antibiotics + mechanical bowel preparation, 262 (1.6 per cent) had intravenous antibiotics + enemas, and 1426 (8.7 per cent) had oral antibiotics + mechanical bowel preparation. With intravenous antibiotics as a baseline comparator, network meta-analysis demonstrated a significant reduction in total surgical site infection risk with intravenous antibiotics + oral antibiotics (OR 0.47 (95 per cent c.i. 0.32 to 0.68)) and intravenous antibiotics + oral antibiotics + mechanical bowel preparation (OR 0.55 (95 per cent c.i. 0.40 to 0.76)), whereas oral antibiotics + mechanical bowel preparation resulted in a higher surgical site infection rate compared with intravenous antibiotics alone (OR 1.84 (95 per cent c.i. 1.20 to 2.81)). Anastomotic leak rates were lower with intravenous antibiotics + oral antibiotics (OR 0.63 (95 per cent c.i. 0.44 to 0.90)) and intravenous antibiotics + oral antibiotics + mechanical bowel preparation (OR 0.62 (95 per cent c.i. 0.41 to 0.94)) compared with intravenous antibiotics alone. There was no significant difference in outcomes with mechanical bowel preparation in the absence of intravenous antibiotics and oral antibiotics in the main analysis. CONCLUSION: A bowel preparation strategy with intravenous antibiotics + oral antibiotics, with or without mechanical bowel preparation, should represent the standard of care for patients undergoing elective colorectal surgery.