45: A randomized trial of closed incision negative pressure therapy in morbidly obese women undergoing cesarean delivery

Abstract

To compare the efficacy of closed incision negative pressure therapy (ciNPT) with a standard surgical dressing in the prevention of post-operative wound morbidity in women with class III obesity undergoing cesarean delivery. In this single-center, randomized controlled trial conducted between 1/2015 and 7/2016, women with class III obesity (BMI ≥40 kg/m2) undergoing cesarean delivery were eligible for study participation. Women on anticoagulation, with HIV infection, sensitive skin disorders, or silver or acrylic allergies were excluded. Women were randomized to placement of a standard surgical dressing or a ciNPT dressing at time of cesarean. All dressings were removed prior to hospital discharge to allow inspection of the incision. The primary study outcome was a composite of wound morbidity including wound disruption requiring the use of antimicrobials, prolonged post-operative hospitalization, hospital readmission, or reoperation within 30 days of delivery. An observational pilot study predicted a 20% baseline prevalence of wound morbidity in this patient population. An a priori power calculation with 80% power (α 0.05) determined that 220 women in each study arm were needed to detect a 50% decrease in wound complication rate. Analysis was performed on an intention-to-treat basis and included χ2 test, Student’s t-test, and Wilcoxon rank-sum test. During the 18-month study period, 677 women were enrolled. Of these, 441 underwent cesarean delivery and were randomized (222 to ciNPT and 219 to standard dressing). Maternal demographic characteristics, including age, race, parity, delivery BMI, and gestational age at delivery were not significantly different between the two cohorts. There were no differences in obstetrical complications or surgical characteristics. Overall wound morbidity for the entire cohort was 18%. 41 women (19%) in the standard group and 37 women (17%) in the ciNPT group developed post-operative wound morbidity (RR 0.9; 95% confidence interval 0.6-1.4; P = 0.62). Median hospital length of stay was 3.2 days for each cohort. Outcomes are shown in Table 1. Wound complications were classified as shown in Table 2. The use of prophylactic ciNPT after cesarean delivery in morbidly obese women is not associated with decreased wound morbidity when compared to a standard surgical dressing.View Large Image Figure ViewerDownload Hi-res image Download (PPT)