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.