Resolution of hydronephrosis after uterine artery embolization for fibroids

Purpose: To determine the prevalence, predisposing factors, and resolution of hydronephrosis among patients undergoing uterine artery embolization (UAE) for fibroids. Materials and Methods: From October 2004 to May 2008, 1,114 patients underwent UAE at an academic medical center. Hydronephrosis was found on angiographic images in 101 patients. In 34 of these patients, 3-month ultrasound follow-up was available. The angiographic images were graded for hydronephrosis severity by three interventional radiologist reviewers. The degree of residual hydronephrosis was obtained from ultrasound images or reports in 3-month follow-up imaging. Descriptive statistics summarizing outcomes and interobserver agreement regarding hydronephrosis grade were calculated. In a parallel assessment, prospectively gathered baseline data available from 776 patients undergoing UAE were analyzed to identify predisposing factors to hydronephrosis. Results: Among the 34 patients with hydronephrosis and appropriate follow-up, resolution occurred in 28 of 34 (82%) patients. Among the entire study group, 9.0% (101 of 1,114) of patients had unilateral or bilateral hydronephrosis. Hydronephrosis was less frequent in left kidneys (4.5% [35 of 776]) than right kidneys (6.3% [49 of 776]; P = .013). The mean uterine volume in the group with hydronephrosis was greater than in the group without hydronephrosis (1,041 cm³ vs 609 cm³; P < .0001), and the mean dominant fibroid volume was also greater (233 cm³ vs 147 cm³; P < .0001). Conclusions: These results suggest that UAE may result in resolution of hydronephrosis in a notable number of cases. Large uterine size and dominant fibroid size was associated with hydronephrosis.