Intra‐abdominal drains for the prophylaxis of anastomotic leak in elective colorectal surgery

Background Elective colorectal surgery can involve formation of bowel anastomoses, which may be complicated by postoperative anastomotic leaks. Routine intra-operative drain placement aims to help clinicians diagnose and treat postoperative leaks. There is little agreement on the prophylactic use of drains for elective colorectal anastomoses. Once anastomotic leakage has occurred, it is generally agreed that drains should be used for therapeutic purposes. However, on prophylactic use no such agreement exists. Objectives To assess the effectiveness and safety of a prophylactic drain after elective colorectal anastomosis. Search methods We searched the Cochrane Colorectal Cancer Group's Specialized Register (February 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 2), Ovid MEDLINE (1950 to February 2015) and Ovid EMBASE (1974 to February 2015). We also searched trial registers for ongoing and registered trials, Clinicaltrials.gov and the World Health Organization (WHO) search platform International Clinical Trials Registry Platform. Selection criteria We included randomised controlled trials (RCTs) comparing drainage with non-drainage regimens after anastomoses in elective colorectal surgery. Data collection and analysis Two review authors independently performed selection of studies, assessment of trial quality and extraction of relevant data; a third review author resolved disagreements. We used GRADE methods to evaluate the quality of evidence. Main results Of the 908 participants enrolled (three RCTs), 454 were allocated for drainage and 454 for no drainage. We found no new RCTs for this review update. Two trials reported the primary outcome measure of anastomotic dehiscence. There was no statistically significant difference in anastomotic dehiscence in participants treated with intra-abdominal drainage routinely compared to no treatment (risk ratio (RR) 1.40, 95% confidence intervals (CI) 0.45 to 4.40; I2 = 0%; 2 RCTs; 809 participants). There was no statistically significant difference in mortality (RR 0.77, 95% CI 0.41 to 1.45; I2 = 0%; 3 RCTs; 908 participants); surgical re-intervention (RR 1.11, 95% CI 0.67 to 1.82; I2 = 29%; 3 RCTs; 908 participants); radiological dehiscence (RR 0.85, 95% CI 0.39 to 1.83; I2 = 0%; 2 RCTs; 809 participants) and wound infection (RR 0.82, 95% CI 0.45 to 1.51; I2 = 0%; 3 RCTs; 908 participants) in participants treated with routine prophylactic drainage compared to no treatment undergoing elective colorectal surgery. The quality of evidence was low according to GRADE method assessment. Authors' conclusions There was insufficient evidence for the use of prophylactic drains after elective colorectal anastomoses. The conclusions of this review were limited due to the nature of the available clinical data; The three included RCTs performed different interventions with relatively small sample sizes of eligible participants.