Systematic review and meta-analysis of the role of defunctioning stoma in low rectal cancer surgery

BACKGROUND DATA: The role of a defunctioning stoma in patients undergoing low anterior resection for rectal cancer is still the subject of controversy. Recent studies suggest reduced morbidity after low anterior rectal resection with a defunctioning stoma. METHODS:: Retrospective and prospective studies published between 1966 and 2007 were systematically reviewed. Randomized controlled trials (RCTs) comparing anterior resections with or without defunctioning stoma were included in a meta-analysis. The pooled estimates of clinically relevant anastomotic leakages and of reoperations were analyzed using a random effects model (odds ratio and 95% confidence interval, CI). RESULTS:: Relevant retrospective single (n = 18) and multicenter (n = 9) studies were identified and included in the systematic review. Analysis of incoherent data of the leakage rates in these nonrandomized studies demonstrated that a defunctioning stoma did not influence the occurrence of anastomotic failure but seemed to ameliorate the consequences of the leak. Four RCTs were included in the meta-analysis. The odds ratio for clinically relevant anastomotic leakage was 0.32 (95% CI 0.17-0.59), revealing a statistically significant benefit conferred through a defunctioning stoma (Z = 3.65, P = 0.0003). The odds ratio for reoperation because of leakage-caused complications was 0.27 (95% CI 0.14-0.51), with significantly fewer reoperations in patients with a defunctioning stoma (Z = 3.95, P < 0.0001). Overall mortality rates were comparable regardless of the presence of a defunctioning stoma. CONCLUSION:: A defunctioning stoma reduces the rate of clinically relevant anastomotic leakages and is thus recommended in surgery for low rectal cancers.