Single- vs multiple-layer wound closure for flank incisions: results of a prospective, randomised, double-blinded multicentre study.

Abstract

To compare the incidence of postoperative flank bulges between patients with multiple-layer closure and single superficial-layer closure after retroperitoneal surgery via open flank incision in the SIngle versus MUltiple-LAyer wound Closure for flank incision (SIMULAC) trial. The study was a randomised controlled, patient- and assessor-blinded, multicentre trial. Between May 2015 and February 2017, 225 patients undergoing flank incisions were randomised 1:1 to a multiple-layer closure (SIMULAC-I) or a single superficial-layer closure (SIMULAC-II) group. The primary outcome was the occurrence of a flank bulge 6months after surgery. Overall, 177 patients (90 in SIMULAC-I, 87 in SIMULAC-II) were eligible for final assessment. The cumulative incidence of a flank bulge was significantly higher in the SIMULAC-II group (51.7%) compared to the SIMULAC-I group [34.4%; odds ratio (OR) 2.04, 95% confidence interval (CI) 1.11-3.73; P=0.02]. Rate of severe postoperative complications (4.4% SIMULAC-I vs 10.3% SIMULAC-II; P=0.21) or hernia (6.7% SIMULAC-I vs 10.3% SIMULAC-II; P=0.59) was similar between the groups. There was no difference in pain (visual analogue scale) and the requirement for pain medication at 6months postoperatively. Quality of life assessed with the European Quality of Life 5 Dimensions Questionnaire was higher in the SIMULAC-I group compared to the SIMULAC-II group at 6months postoperatively, with a (median range) score of 80 (30-100) vs 75 (5-100) (P=0.012). The overall risk of a flank bulge after flank incision is high. Multiple-layer closure after flank incision should be performed as a standard procedure.