Clinical analysis of uterus preservation for placenta previa complicated with placenta accreta spectrum by pre-freeing the bladder combined with fishnet-like reconstruction of the lower uterine segment

Objective To observe the effectiveness of uterus preservation and intraoperative blood loss for placenta previa complicated with placenta accreta spectrum (PAS) by pre-freeing the bladder combined with fishnet-like reconstruction of the lower uterine segment.Methods This study reviewed the clinical outcomes of 104 patients who underwent cesarean section in our hospital due to scarred uterus with placenta previa and placenta accreta spectrum from November 1st, 2019 to December 31st, 2022. The 104 patients were divided into the group of intraoperative blood loss ≥2000ml with 20 cases and the group of intraoperative blood loss <2000ml with 84 cases. We analyzed the risk factors of intraoperative blood loss ≥2000ml in this surgical procedure through univariate analysis and multivariate logistic regression analysis.Results Of the 104 pregnant women, the median gestational age of delivery was 35+2 (33+5~36+2) weeks , the median intraoperative blood loss was 1200 (800~1575)ml, the median volume of autologous blood reinfusion was 450 (250-800)ml, the median allogeneic suspended red blood cell infusion was 2.0 (1.5~3.4)U, 103 cases (99.0%) successfully preserved the uterus, 1 case underwent cesarean hysterectomy, 7 cases (6.7%) experienced surgical complications, there was no maternal death. We found that placenta percreta （OR 7.284，95%CI 1.443~36.759，P=0.016）, prenatal cervical canal length ≤25mm（OR 5.340，95%CI 1.561~18.267，P=0.008）, and placental fenestration（OR 5.845，95%CI 1.307~26.145，P=0.021） were independent risk factors for intraoperative blood loss ≥2000 ml during cesarean section.Conclusions For patients with scarred uterus complicated by placenta accreta spectrum and placenta previa, pre-freeing the bladder combined with fishnet-like reconstruction of the lower uterine segment has a good effect in controlling hemorrhage and preserving uterus during cesarean section, and has a low incidence of surgical complications. Patients with placenta percreta, a prenatal cervical canal length ≤25 mm, and placental fenestration have a significantly increased risk of intraoperative hemorrhage.