To drain or not to drain in colorectal anastomosis: a meta-analysis

BACKGROUND: Currently, many surgeons place a prophylactic drain in the abdominal or pelvic cavity after colorectal anastomosis as a conventional treatment. However, some trials have demonstrated that this procedure may not be beneficial to the patients. OBJECTIVE: To determine whether prophylactic placement of a drain in colorectal anastomosis can reduce postoperative complications. METHODS: We systematically searched all the electronic databases for randomized controlled trials (RCTs) that compared routine use of drainage to non-drainage regimes after colorectal anastomosis, using the terms "colorectal" or "colon/colonic" or "rectum/rectal" and "anastomo*" and "drain or drainage." Reference lists of relevant articles, conference proceedings, and ongoing trial databases were also screened. Primary outcome measures were clinical and radiological anastomotic leakage. Secondary outcome measures included mortality, wound infection, re-operation, and respiratory complications. We assessed the eligible studies for risk of bias using the Cochrane Risk of Bias Tool. Two authors independently extracted data. RESULTS: Eleven RCTs were included (1803 patients in total, 939 patients in the drain group and 864 patients in the no drain group). Meta-analysis showed that there was no statistically significant differences between the drain group and the no drain group in (1) overall anastomotic leakage (relative risk (RR) = 1.14, 95 % confidence interval (CI) 0.80-1.62, P = 0.47), (2) clinical anastomotic leakage (RR = 1.39, 95 % CI 0.80-2.39, P = 0.24), (3) radiologic anastomotic leakage (RR = 0.92, 95 % CI 0.56-1.51, P = 0.74), (4) mortality (RR = 0.94, 95 % CI 0.57-1.55, P = 0.81), (5) wound infection (RR = 1.19, 95 % CI 0.84-1.69, P = 0.34), (6) re-operation (RR = 1.18, 95 % CI 0.75-1.85, P = 0.47), and (7) respiratory complications (RR = 0.82, 95 % CI 0.55-1.23, P = 0.34). CONCLUSIONS: Routine use of prophylactic drainage in colorectal anastomosis does not benefit in decreasing postoperative complications