Effectiveness of Uterine Arterial Embolization and Risk Factors Associated with Its Failure in Patients with Primary Postpartum Hemorrhage After Cesarean Section

Background: Postpartum hemorrhage (PPH), a serious labor-related complication, is the leading cause of maternal mortality, which requires an emergent intervention. Uterine arterial embolization (UAE) is an effective treatment for hemostasis of intractable PPH. Several risk factors have been reported for the failure of UAE. Objectives: To evaluate the clinical outcomes of UAE for the treatment of primary PPH following cesarean section (CS) and to determine the risk factors associated with the failure of this procedure. Methods: This retrospective, single-center study was approved by the institutional review board, and the requirement to obtain informed consent was waived. All patients referred to a tertiary care center, who underwent UAE for primary PPH between January 2018 and December 2020, were included. The patients’ medical records and radiological findings, including the patients’ characteristics, mode of delivery, initial vital signs and laboratory findings after hospitalization, procedure details, and embolization outcomes, were evaluated for data collection. Technical success was defined as appropriate embolization of target vessels on a completion angiogram. Clinical success was defined as adequate cessation of bleeding after the first embolization, without any need for subsequent embolization or surgical intervention. Statistical analysis was performed to determine factors related to the clinical failure of UAE in CS cases. Results: UAE was performed for 25 patients (mean age, 37.2 years; range, 25 - 45 years). The technical success rate was estimated at 100% (n = 25), and the clinical success rate was 76% (n = 19). There were no patients with permanent adverse sequelae or death. The univariate analyses showed that hemodynamic instability (P = 0.006), lower hemoglobin levels (P = 0.02), and prolonged activated partial thromboplastin time (aPTT) (P = 0.017) were related to clinical failure. The logistic regression analysis adjusted for age showed that the area under the curve (AUC) was 0.86 for hemoglobin (95% CI: 0.7 - 1; cutoff value: 0.667), 0.816 for aPTT (95% CI: 0.625 - 1; cutoff value: 0.411), and 0.868 for hemodynamic instability (95% CI: 0.661 - 1; cutoff value: 0.622). Conclusions: UAE is a safe and effective treatment for primary PPH following CS. Hemodynamic instability, low hemoglobin levels, and prolonged aPTT can be predictive factors for the poor outcomes of UAE in CS patients. These factors are rapid and straightforward criteria, which can be simply applied, even in emergency situations.