Ultrasound evaluation of uterine healing after vaginal repair of cesarean section scar defect: An observational study

Abstract

Abstract Background Many cesarean section scar defects (CSD) patients worry about thin thickness of the residual myometrium (TRM) and want to avoid uterine rupture in subsequent pregnancies. In addition, some blood flow indices could be possible predictive markers for impaired wound healing. To date, there is no method to dynamically assess the healing process in the uterine repair of CSD. To evaluate the association between uterine healing and uterine artery blood flow changes after vaginal repair of CSDs with two-dimensional power Doppler ultrasound and Doppler velocimetry. Methods A cohort prospective study (level of evidence II-2), run in University-affiliated hospitals: 98 women with CSDs underwent VR, between June 2021 and March 2022. During follow up 9 patients withdrew from the study. After vaginal repair, all patients were followed by traditional two-dimensional power Doppler ultrasound scanning and Doppler velocimetry preoperatively and at 2 days, 1 month and 3 months postoperatively. The size and location of the CSDs, TRM and Doppler velocimetry of the uterine arteries were evaluated. Results The thickness of the residual myometrium was significantly improved after vaginal repair (P < 0.05). However, it gradually became thinner over time. There was a significant (P < 0.05) progressive reduction in the uterine scar area from 82% on the second day in the first month to 67% in the third month. The pulsation index (PI), resistance index (RI), and systolic peak flow rate/diastolic flow rate (S/D) of the uterine artery showed little change after vaginal repair. The peak systolic velocity (PSV) value of the uterine artery significantly increased from 50.35 preoperatively to 53.92 on the second day after repair (p = 0.006). In total, 89 women had the symptom of postmenstrual spotting before repair, and 71.9% (64/89) of these patients returned to normal menstruation after repair. According to the preoperative duration of menstruation, the patients were divided into two groups (menstruation duration ≤ 7 days group and menstruation duration > 7 days group). The PSV values of the uterine artery in the first postoperative month were 53.32 ± 8.49 and 48.24 ± 7.35, respectively, and there was a significant difference between the two groups (p = 0.028). Conclusion The TRMs of CSD patients can be improved by vaginal repair. Traditional two-dimensional ultrasound and Doppler velocimetry can dynamically assess the healing process of the uterus after vaginal repair. Moreover, the PSV value in the first month after surgery may be a marker for predicting wound healing.