Uterus-preserving management of a high-flow uterine artery pseudoaneurysm with arteriovenous fistula following cesarean section: a case report.

Postpartum uterine vascular lesions are a rare but important cause of secondary postpartum hemorrhage. This report describes the case of a 29-year-old woman presenting five weeks after repeat cesarean section with recurrent vaginal bleeding. Transvaginal color Doppler ultrasound demonstrated a 2.7 cm anechoic lesion adjacent to the cesarean scar with marked hypervascularization and a high-flow pattern (peak systolic velocity up to 310 cm/s, low resistance indices) with pulsatile venous outflow, suggestive of a combined uterine artery pseudoaneurysm and arteriovenous fistula. Computed tomography CT angiography confirmed a pseudoaneurysm of the uterine artery with early venous drainage via the right uterine vein. Selective embolization of the right uterine artery resulted in a substantial but incomplete reduction in flow. Follow-up Doppler ultrasound demonstrated persistent perfusion, and repeat embolization was required to treat residual feeders from both uterine and ovarian circulation. Serial Doppler assessment showed progressive reduction in flow velocities and lesion size, with complete sonographic resolution after four months. One year later, the patient had another successful pregnancy. This case illustrates that high-flow uterine vascular lesions following cesarean section may involve complex collateral supply and require repeat embolization. Transvaginal color Doppler ultrasound is central not only for initial diagnosis but also for monitoring treatment response. Persistent flow after initial embolization does not necessarily indicate treatment failure but may reflect collateral reperfusion amenable to targeted re-intervention. Uterus-preserving management can result in complete resolution and allow subsequent pregnancy.