Preventing Isthmocele after Cesarean Section (PICS): A Pilot Randomized Controlled Trial

ABSTRACT

Study Objective An isthmocele is a cesarean scar site defect with a depth of >2mm and can lead to both obstetric and gynecologic complications. The primary objective was to evaluate the feasibility of a study protocol comparing different cesarean section closure techniques amongst our own patients/physicians, with the ultimate goal of a larger scale randomized controlled trial (RCT). Secondary objectives included isthmocele incidence, measurements on postoperative ultrasound, and adverse surgical outcomes related to suture technique. Design A single-center parallel-group pilot RCT comparing locked vs. unlocked first-layer uterine closure. Outpatient transvaginal ultrasound to evaluate isthmocele formation was performed at least six months postoperatively. Setting Operating room and outpatient ultrasound clinic. Patients or Participants All term pregnant patients >18 years old undergoing a primary caesarean section were eligible. Exclusion criteria included previous uterine hysterotomy, known uterine anomalies, active labour, and maternal bleeding and/or connective tissue disorders. Interventions Locked or unlocked closure of the first uterine layer. Measurements and Main Results Forty-one subjects were randomized, and 23 completed the follow-up ultrasound, with 12 in the locked group and 11 in the unlocked group. Barriers to feasibility included hesitance to participate in research during pregnancy, difficulty attending follow-up ultrasound with a newborn, and mainly Covid-19 pandemic related delays in study activities and fear of potential exposures. Isthmocele was present in 10/12 patients receiving locked closure, and in 11/11 of the unlocked group. Mean sagittal depth was 0.36 cm and 0.40 cm in the locked vs. unlocked groups, respectively. Sagittal adjacent myometrial thickness was 1.03 cm in the locked group, and 1.12 cm in the unlocked group. No adverse outcomes were noted with either surgical technique. Conclusion The study design is feasible outside of the pandemic setting. A larger trial is needed to determine differences regarding isthmocele rates and measurements between groups.