Monofilament vs multifilament suture for uterine closure at the time of cesarean delivery: a randomized clinical trial

Objective: To test whether uterine closure using synthetic absorbable monofilament sutures at the time of cesarean delivery would reduce the rate of cesarean scar defects compared to uterine closure using synthetic absorbable multifilament sutures. Methods: Parallel-group, nonblinded, randomized clinical trial of women with singleton pregnancies undergoing cesarean delivery at term in a single center in Italy. Inclusion criteria were singleton pregnancy, first or second cesarean delivery, scheduled and emergent or urgent cesarean delivery, gestational age between 37 0/7 and 42 0/7 weeks. Eligible participants were randomly allocated in a 1:1 ratio to either the monofilament (Polyglytone 6211; Caprosyn, Covidien) or to the multifilament suture group (coated Polyglactin 910 suture with Triclosan; Vicryl Plus, Ethicon). The primary outcome was the incidence of cesarean scar defect at ultrasound at the 6 months follow-up visit. The secondary outcomes were residual myometrial thickness (RMT), and symptoms. Results: 300 women were included in the trial. Of the randomized women, 151 were randomized to the monofilament and 149 to the multifilament group. 27 women were lost to follow up, 15 in the monofilament group, and 12 in the multifilament group. Six months after delivery, the incidence of cesarean scar defect was 18.4% (25/136) in the monofilament group, and 23.4% (32/137) in the multifilament group (relative risk 0.79; 95% CI 0.41 to 1.25; p= 0.31). The mean RMT was 7.6 mm in the monofilament group, and 7.2 mm in the multifilament group (mean difference +0.40 mm, 95% CI -0.23 to 1.03). No between group significant differences were found in the incidence of symptoms, including pelvic pain, painful periods, and dyspareunia. Conclusions: In singleton gestations undergoing primary or second cesarean delivery, use of synthetic absorbable monofilament sutures at the time of uterine wall closure was not associated with a reduction in the rate of cesarean scar defect 6 months after delivery compared to use of synthetic absorbable multifilament sutures.