Abdominal drainage versus no drainage post gastrectomy for gastric cancer.

BACKGROUND

Gastrectomy remains the primary therapeutic method for resectable gastric cancer. Thought of as an important measure to reduce post-operative complications and mortality, abdominal drainage was used widely after gastrectomy for gastric cancer in previous decades. The benefits of abdominal drainage have been questioned by researchers in recent years.

OBJECTIVES

The objectives of this review were to access the benefits and harms of routine abdominal drainage post gastrectomy for gastric cancer.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (Central/CCTR) in The Cochrane Library (2010, Issue 10), including the Specialised Registers of the Cochrane Upper Gastrointestinal and Pancreatic Diseases (UGPD) Group; MEDLINE (via Pubmed, 1950 to October, 2010); EMBASE (1980 to October, 2010); and the Chinese National Knowledge Infrastructure (CNKI) Database (1979 to October, 2010).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing abdominal drain versus no drain in patients who had undergone gastrectomy (not considering the scale of gastrectomy and the extent of lymphadenectomy; irrespective of language, publication status, and the type of drain). We excluded RCTs comparing one drain with another.

DATA COLLECTION AND ANALYSIS

From each trial, we extracted the data on the methodological quality and characteristics of the included studies, mortality (30-day mortality), re-operations, post-operative complications (pneumonia, wound infection, intra-abdominal abscess, anastomotic leak, drain-related complications), operation time, length of post-operative hospital stay and initiation of soft diet. For dichotomous data, we calculated the risk ratio (RR) and 95% confidence intervals (CI). For continuous data, we calculated mean differences (MD) and 95% CI. We tested heterogeneity using the Chi(2) test. We used a fixed-effect model for data analysis with RevMan software but we used a random-effects model if the P value of the Chi(2) test was less than 0.1.

MAIN RESULTS

We included four RCTs involving 438 patients (220 patients in the drain group and 218 in the no-drain group).There was no evidence of a difference between the two groups in mortality (RR 1.73, 95% CI 0.38 to 7.84); re-operations (RR 2.49, 95% CI 0.71 to 8.74); post-operative complications (pneumonia: RR 1.18, 95% CI 0.55 to 2.54; wound infection: RR 1.23, 95% CI 0.47 to 3.23; intra-abdominal abscess: RR 1.27, 95% CI 0.29 to 5.51; anastomotic leak: RR 0.93, 95% CI 0.06 to 14.47); and initiation of soft diet (MD 0.15 day, 95% CI -0.07 to 0.37). However, the addition of a drain prolonged the operation time (MD 9.07 min, 95% CI 2.56 to 15.57) and post-operative hospital stay (MD 0.69 day, 95% CI 0.18 to 1.21) and lead to drain-related complications. Additionally, we should note that 30-day mortality and re-operations are very rare events and, as a result, very large numbers of patients would be required to make any sensible conclusions about whether the two groups were similar. The overall quality of the evidence according to the GRADE approach was "Very Low" for mortality and re-operations, and "Low" for post-operative complications, operation time, and post-operative length of stay.

AUTHORS' CONCLUSIONS: We found no convincing evidence to support routine drain use after gastrectomy for gastric cancer.