Drain Placement After Uncomplicated Hepatic Resection Increases Severe Postoperative Complication Rate: A Japanese Multi-institutional Randomized Controlled Trial (ND-trial)

To assess the clinical impact of a no-drain policy after hepatic resection. Previous randomized controlled trials addressing no-drain policy after hepatic resection seem inconclusive because they did not adopt appropriate study design to validate its true clinical impact. This unblinded, randomized controlled trial was done at 7 Japanese institutions. Patients undergoing hepatic resection without biliary reconstruction were randomized to either D group or ND group. When the risk of postoperative bile leakage or hemorrhage were considered high, the patients were excluded during the operation. Primary endpoint was the postoperative complication of C-D grade 3 or higher within 90 postoperative days. A noninferiority of ND group to D group was assessed, and if it was confirmed, a superiority was assessed. Between May 2015 and July 2017, a total of 400 patients were finally included in the per-protocol set analysis: 199 patients in D group and 201 patients in ND group. Intraoperatively, 37 patients were excluded from the final enrollment because of high risk of bile leakage or hemorrhage. Postoperative complication rate of C-D grade 3 or higher was 8.0% (16/199) in the D group and 2.5% (5/201) in the ND group. The risk difference was -5.5% (95% confidence interval: -9.9% to -1.2%) and fulfilled the prescribed noninferiority margin of 4%. No postoperative mortality was experienced in both groups. Bile leakage was diagnosed in 8.0% (16/199) of the D group and none in the ND group (P < 0.001). In none of the subgroups classified based on 8 potentially relevant factors, drain placement was favored in terms of C-D grade 3 or higher complication. Drains should not be placed after uncomplicated hepatic resections.