[Effect factors of collateral blood supply of patients with early trimester cesarean scar pregnancy].

To investigate the characteristics and effect factors of collateral blood supply of patients with early trimester cesarean scar pregnancy(CSP). This study was a multicenter case-control study, with 219 inpatients with CSP in First People's Hospital of Zhengzhou, Zhengzhou Central Hospital, Third People's Hospital of Zhengzhou and Henan No3 Provincial People's Hospital from January 1, 2017 to June 30, 2020 who were selected to obtain their clinical data. Double-blind method was performed in digital subtraction angiography imaging analysis. The patients were divided into collateral blood supply group and non-collateral blood supply group, and the incidence of collateral blood supply of patients with early trimester CSP was calculated. Multivariate binary logistic regression analysis was performed to find the independent risk factors of collateral blood supply of patients with early trimester CSP. As well, clinical outcomes after uterine artery embolization (UAE) were compared between the two groups. A total of 219 patients with early trimester CSP have average age of (32.4±5.0) years old and average pregnancy of (51.0±10.6) days. The incidence of collateral blood supply was 12.3% (27 cases), of which16 cases were on the left, 6 on the right and 5 in both sides. A total of 43 collateral vessels were found, with 1.59 vessels per patient on average. Bladder artery was the most common source of collateral blood supply, accounting for 74.4% (32/43), followed by internal pudendal artery for 18.6% (8/43). Multivariate binary logistic regression analysis showed that gestational weeks ≥8 weeks, maximum diameter of gestational sac ≥50 mm and rich blood supply of gestational sac are independent risk factors for collateral blood supply of patients with early trimester CSP, with (95%) 3.68 (1.06-12.76), 7.00 (1.52-32.19)、9.96 (3.59-27.58), respectively, all 0.05. The success rates of UAE were 100% in both groups. The reduction in serum β-Human chorionic gonadotropin (β-HCG) level at 24 hours after UAE, vaginal bleeding during uterine curettage, hysterectomy and menstrual recovery time were not found to have significant difference between groups (all >0.05). Early trimester CSP leads to a certain occurrence of collateral blood supply, which may have adverse impact on the efficacy of UAE and patient safety. Gestational weeks, the maximum diameter of gestational sac and the degree of vascularization of gestation sac have certain value in suggesting the collateral blood supply of patients with early trimester CSP, which is helpful for the complete embolization of gestational sac in the process of UAE.