Leiomyoma infarction after uterine artery embolization: A prospective randomized study comparing tris-acryl gelatin microspheres versus polyvinyl alcohol microspheres

PURPOSE: To determine the degree of leiomyoma infarction after uterine artery embolization (UAE) performed with tris-acryl gelatin microspheres or polyvinyl alcohol (PVA) microspheres. MATERIALS AND METHODS: Patients determined to be candidates and scheduled for UAE were randomized prospectively to receive tris-acryl gelatin microspheres or PVA microspheres. The manufacturers' recommended technique was used for both products during the UAE procedures (including the recently described refined protocol for PVA microspheres). All patients underwent magnetic resonance (MR) imaging of the pelvis with contrast agent enhancement before and after the UAE procedure. On the postprocedural MR study, the degree of tumor infarction was assessed on postcontrast images. These findings were classified as follows: 100% infarction, 90%-99% infarction, 50%-89% infarction, and less than 50% infarction. Treatment failure was defined by enhancement of more than 10% of a patient's entire tumor burden. RESULTS: A total of 53 patients were enrolled in this study. Twenty-seven (mean age, 44.9 years) received PVA microspheres and 26 (mean age, 45.1 years) received tris-acryl gelatin microspheres. There were no significant differences in the preprocedural uterine volume, dominant tumor volume, location of dominant tumor, and presenting symptoms between populations. In the PVA microsphere group, treatment failure was seen in eight patients (29.6%). In the tris-acryl gelatin microsphere group, treatment failure was seen in one patient (3.8%), which was a significant difference between groups (P <= .025). CONCLUSIONS: There was a significantly greater degree of tumor infarction in patients treated with tris-acryl gelatin microspheres during UAE than in patients who received PVA microspheres administered in accordance with a newly refined protocol. Given the known risk of recurrence in patients with persistent tumor enhancement after UAE, it is concluded that tris-acryl gelatin microspheres should be the preferred agent for UAE at this time.