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 was conducted from inception to August 22, 2023, of PubMed, Embase, Cochrane Library, and Google Scholar databases.

STUDY SELECTION: Randomized controlled trials and propensity score matched studies.

INTERVENTIONS: Emergency colonic resection, self-expanding metallic stent, decompressing stoma.

MAIN OUTCOME MEASURES: Oncologic efficacy, morbidity, successful minimally invasive surgery, primary anastomosis, and permanent stoma rates.

RESULTS: Nineteen articles from 5225 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) both 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 an increase in stenting (risk ratio 1.40, 95% credible interval: 1.31, 1.49) as 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) when compared with resection. There were no differences in disease-free and overall survival rates, respectively.

LIMITATIONS: There is a lack of randomized controlled trial and propensity score matching data comparing short 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.

CONCLUSION: This study provides high-level evidence that 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 as compared to emergency colonic resection.