We designed this review to compare drainage with non-drainage in people having colorectal surgery (a procedure that is used to repair damage to the colon, rectum, anus and muscle of the lower belly) with bowel anastomosis (where two ends of the bowel are joined to each other). Elective colorectal surgery (where surgery is planned in advance rather than carried out as an emergency) often involves removal of part of the large bowel for a variety of diagnoses with subsequent anastomosis. There is the option for the surgeon to place a drain at the time of surgery to prevent leakage from the anastomosis. This is called a prophylactic drain. Cochrane review authors assessed the evidence for the routine use of prophylactic drain placement after the formation of colorectal anastomoses.
We included three clinical trials involving 908 participants. The trials were conducted in Germany and France. All trials compared routine anastomotic drainage versus no anastomotic drainage after elective colorectal surgery. The evidence was current to February 2015.
This review showed no apparent difference in anastomotic leak, death, radiological (x-ray) evidence of anastomotic leak, wound infection or need for re-operation. We found insufficient evidence to support the use of routine prophylactic drains after elective colorectal anastomosis. We based our conclusion on limited evidence with relatively small numbers of participants; this means that it is difficult to detect differences between treatment groups that may be present.
Quality of the evidence
The quality of the evidence was low, making it impossible to draw firm conclusions about the use of routine prophylactic drains after elective colorectal anastomosis. Additional studies are needed to strengthen the conclusion drawn by this systematic review and to provide further analysis using modern colorectal surgery. We found no new evidence since the previous version of our systematic review of 2004.
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.
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.
To assess the effectiveness and safety of a prophylactic drain after elective colorectal anastomosis.
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.
We included randomised controlled trials (RCTs) comparing drainage with non-drainage regimens after anastomoses in elective colorectal surgery.
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.
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.