Randomized controlled trial of single-use negative-pressure wound therapy dressings in morbidly obese patients undergoing cesarean delivery

BACKGROUND: The single-use negative-pressure wound therapy dressings are designed to use over a closed surgical wound. Early prospective studies suggested that these dressings may be of potential benefit in reducing cesarean wound complications. OBJECTIVE: This study aimed to test the hypothesis that incisional negative-pressure wound therapy decreases postoperative wound morbidity compared with standard surgical dressing in patients with class III obesity undergoing cesarean delivery. STUDY DESIGN: In a single-site, parallel, randomized controlled trial, participants with class III obesity (body mass index >= 40 kg/m(2)) were recruited to participate in the study. Patients were consented in the ambulatory obstetrical units, on admission to the antepartum service, and on labor and delivery before active labor. Patients who had a cesarean delivery were randomized to either the standard surgical dressing or a prophylactic negative-pressure wound therapy device. The randomization was achieved using permuted blocks of 4, 6, and 8 in a 1:1 allocation ratio. The primary outcome was a composite outcome of wound complications. The planned enrollment of 242 subjects was based on the power to detect a 50% decrease in the composite wound outcome, assuming a 30% baseline wound morbidity rate for this population. The outcomes were assessed by study staff blinded to the patient's treatment arm. RESULTS: An unplanned interim analysis was performed because of the slow enrollment and publication of larger trials showing no benefit of the negative-pressure wound therapy. Of 411 eligible patients during the study period, 212 participants with class III obesity were enrolled. Of these, 110 underwent cesarean delivery and were subsequently randomized (55 to standard dressing and 55 to prophylactic negative-pressure wound therapy device). The primary outcome occurred in 29.1% in the standard surgical dressing compared with 20% in the negative-pressure wound therapy group (risk difference, 9.1%; 95% confidence interval, -8.3 to 25.8%; P=.38). The study was stopped early because of a low enrollment rate and lower likelihood of seeing a clinically significant benefit. CONCLUSION: The trial was stopped after an unplanned, interim analysis showed the use of a prophylactic negative-pressure wound therapy device used for cesarean delivery did not reduce wound complications compared with a standard surgical dressing.