PurposeTo study the factors that might impact infarction of individual uterine leiomyomas and total tumor burden after uterine artery embolization (UAE). Materials and MethodsThis retrospective study included 91 patients (mean age, 44 y [range, 34–54 y]) who underwent UAE with tris-acryl gelatin microspheres (TAGMs) or nonspherical polyvinyl alcohol (PVA) particles. Twenty-one patients were treated with PVA (23%) and 70 were treated with TAGMs (77%). A total of 356 uterine leiomyomas were assessed, with a median uterine volume of 533 cm3 (range, 321–848 cm3). A reader masked to demographic and technical details reviewed contrast-enhanced magnetic resonance images before and 3 months after UAE to estimate the extent of tumor infarction. ResultsThere was no significant difference in global or individual tumor infarction rate between embolizations with TAGMs and PVA particles (P = .73 and P = .3, respectively). Global infarction was not affected by age (P = .53), race (P = .12), number of leiomyomas (P = .72), or uterine volume (P = .74). Leiomyoma size did not influence individual tumor infarction (P = .41). Leiomyoma location was the sole factor that influenced individual tumor infarction rates, with pedunculated serosal tumors significantly less likely to show complete infarction than transmural tumors (odds ratio, 0.24; P = .01). ConclusionsNonspherical PVA particles and TAGMs produce similar rates of uterine leiomyoma infarction. Complete infarction of individual tumors is less likely in serosal and pedunculated serosal tumors.