Incomplete Uterine Artery Embolization Secondary to Collateral Parasitization from Celiac and Superior Mesenteric Arterial Branches: A Case Report and Literature Review

Background and Clinical Significance: Uterine artery embolization (UAE) is a well-established treatment for symptomatic leiomyomas; however, treatment failure may occur owing to collateral arterial supply from extra-uterine sources. While ovarian artery collaterals are the most commonly reported cause, parasitic vascularization from the celiac axis and superior mesenteric artery (SMA) remains exceedingly rare and poorly documented; Case Presentation: A 41-year-old woman with symptomatic fibroids underwent technically successful bilateral UAE. Follow-up imaging revealed persistent vascularity of a dominant 19 cm pedunculated fibroid supplied by collateral branches from the celiac axis and SMA. As surgery was contraindicated owing to a recent pulmonary embolism that occurred after UAE, gonadotropin-releasing hormone (GnRH) agonist therapy was initiated, resulting in partial fibroid shrinkage and symptomatic improvement; Conclusions: Persistent fibroid vascularization after technically successful UAE may result from unrecognized extra-uterine arterial feeders. Cross-sectional angiographic imaging is essential for identifying atypical collateral pathways and guiding subsequent management in cases of treatment failure.