Barbed Versus Conventional Sutures for Cesarean Uterine Scar Defects: A Randomized Clinical Trial

Background The role of barbed sutures in preventing myometrial defects and enhancing postpartum outcomes after cesarean section is uncertain. Objective This study compared clinical and ultrasonographic outcomes of uterine scar defects after C-section with barbed and conventional smooth thread sutures. Study Design This was a multicenter, parallel-group, randomized, controlled clinical trial. Four obstetrics and gynecology departments across three Japanese healthcare regions were included. The participants were women requiring their first cesarean delivery between May 2020 and March 2023. Of the 1211 participants enrolled, 298 underwent cesarean section and 253 were followed-up until July 2023. Participants with singleton pregnancies were randomly assigned (1:1 ratio) to receive either conventional or spiral thread sutures with a double-layer continuous suture. The study period comprised the time of consent to the 6- to 7-month examination. The primary endpoint was the rate of scar niches >2 mm evaluated using transvaginal ultrasonography at 6 to 7 months after surgery. Additional metrics included the total operative time, suture application time, operative blood loss, number of additional sutures required for hemostasis, maternal surgical complications, postoperative infections, surgeon's years of experience, and individual subscale scores. Results All data of the 220 participants (barbed suture group: 110; conventional suture group: 110) were available, thus enabling a full analysis set. A comparison of the barbed and conventional suture groups, respectively, revealed the following: niche length, 2.45±1.65 mm (range: 1.0–6.7) versus 3.79±1.84 mm (range: 1.0–11.0) (P<0.001); niche depth, 1.78±1.07 mm (range: 1.0–5.7) versus 2.70±1.34 mm (range: 1.0–7.3) (P<0.001); residual myometrial thickness, 8.46±1.74 mm (range: 4.8–13.0) versus 7.07±2.186 mm (range: 2.2–16.2) (P<0.001); and niche width, 1.58±2.73 mm (range: 0.0–14.0) versus 2.88±2.36 mm (range: 0.0–11.0) (P<0.001), respectively. The barbed suture group exhibited no defects and a residual myometrial thickness <3 mm. Furthermore, the barbed suture group had a lower rate of uterine niches (29.1%; n=32/110) than the conventional suture group (68.2%; n=75/110). Secondary outcomes showed no significant differences in operative times, maternal surgical complications, or postoperative complications. Conclusions Double-layer barbed sutures during cesarean delivery may prevent cesarean section scar defects and postoperative complications.