Polyvinyl Alcohol Particle Size for Uterine Artery Embolization: A Prospective Randomized Study of Initial Use of 350-500μm Particles versus Initial Use of 500-700μm Particles

PURPOSE: To evaluate whether different polyvinyl alcohol (PVA) particle sizes change the outcome of uterine artery embolization (UAE). MATERIALS AND METHODS: This randomized prospective study comprised 160 patients with symptomatic leiomyomas undergoing UAE with PVA particles from January to August 2008. In 80 patients in group A, UAE was started with 350-500 mu m particles; in 80 patients in group B, UAE was started with 500-700 mu m particles. UAE was finished with larger particles when necessary (500-700 mu m and 700-900 mu m for group A; 700-900 mu m for group B). Visual analogue scales were used to measure pain during and in the 4-8 hours after embolization. The outcome of UAE was evaluated at 6 months by pelvic magnetic resonance (MR) imaging, clinical observation, and response to questionnaires. RESULTS: In group A, PVA particle sizes were as follows: 350-500 mu m in 45 patients; 350-500 mu m and 500-700 mu m in 24 patients; and 350-500 mu m, 500-700 mu m, and 700-900 mu m in 11 patients. In group B, PVA particle sizes were as follows: 500-700 mu m in 66 patients and 500-700 mu m and 700-900 mu m in 14 patients. Mean pain scores during embolization were 1.44 (group A) and 0.97 (group B); after embolization, mean pain scores were 4.71 (group A) and 3.42 (group B) (P < .0001). At 6 months, there were no statistically significant differences in decrease in size of uterus and dominant leiomyoma, in dominant leiomyoma ischemia (P = .31; P = .32), or in the clinical outcome between the two groups. CONCLUSIONS: The initial use of PVA particle sizes 350-500 mu m was associated with a higher mean pain score during and after UAE, although the outcome at 6 months was similar compared with the initial use of particle sizes 500-700 mu m.