Is a drain necessary after anterior resection of the rectum? A systematic review and meta-analysis

Objective: The anastomotic leak rate in colorectal surgery is highest in patients receiving anterior rectal resections. The placement of prophylactic pelvic drains remains a routine option for preventing postoperative leaks, despite increasing evidence suggesting no clinical benefit. The present study seeks to identify a consensus on the use of prophylactic drains in anterior rectal resections. Methods: A systematic search was conducted of MEDLINE, Scopus, EMBASE, and Cochrane Library databases to identify clinical trials comparing the use of drainage to non-drainage in cases of colorectal anastomosis. Results: Three randomized clinical trials (RCTs) and two controlled clinical trials (CCTs) were identified that met the inclusion criteria, with a total of 1702 patients with rectal cancer who underwent anterior resection: 1206 with a pelvic drain and 496 without a pelvic drain. Meta-analysis showed that the use of a drain did not significantly improve the outcomes of anastomotic leaks; the overall reoperation rate during the 30-day postoperative period and the postoperative mortality were statistically lower in the drained group (OR 2.82, 95% CI 1.33 to 5.97; I 2 = 0%). Conclusions: The use of prophylactic pelvic drainage after anterior rectal resections does not provide significant benefits with respect to anastomotic leaks and overall complication rates. However, an approximately threefold reduction of the postoperative mortality of the drained patients was observed. Given the limitations of the present study, these findings warrant the use of a drain after anterior rectal resection. Nevertheless, due to the low quality of the available data, further multicenter trials with uniform inclusion criteria are needed to evaluate drain usage in the anterior rectal resection.