Colon and rectal anastomoses do not require routine drainage - A systematic review and meta-analysis

7Objective Many surgeons continue to place a prophylactic drain in the pelvis after co mpletion of a colorectal anastomosis, despite considerable evidence that th is practice may not be useful. The authors conducted a systematic review an d meta-analysis of randomized controlled trials to determine if placement o f a drain after a colonic or rectal anastomosis can reduce the rate of comp lications. Methods A search of the Medline database of English-language articles published fro m 1987 to 1997 was conducted using the terms "colon," "rectum," "postoperat ive complications," "surgical anastomosis," and "drainage." A manual search was also conducted. Four randomized controlled trials, including a total o f 414 patients, were identified that compared the routine use of drainage o f colonic and/or rectal anastomoses to no drainage; Two reviewers assessed the trials independently. Trial quality was critically appraised using a pr eviously published scale, and data on mortality, clinical and radiologic an astomotic leakage rate, wound infection rate, and major complication rate w ere extracted. Results The overall quality of the studies was poor. Use of a drain did not signifi cantly affect the rate of any of the outcomes examined, although the power of this analysis to exclude any difference was low. Comparison of pooled re sults revealed an odds ratio for clinical leak of 1.5 favoring the control (no drain) group. Of the 20 observed leaks among all four studies that occu rred in a patient with a drain in place, in only one case (5%) did pus or e nteric content actually appear in the effluent of the existing drain. Conclusions Any significant benefit of routine drainage of colon and rectal anastomoses in reducing the rate of anastomotic leakage or other surgical complication s can be excluded with more confidence based on pooled data than by the ind ividual trials alone. Additional well-designed randomized controlled trials would further reinforce this conclusion.