The Efficacy, Safety and Durability of Selective Renal Arterial Embolization in Treating Symptomatic and Asymptomatic Renal angiomyolipoma

Abstract

To review the long-term outcome of selective renal arterial embolization (SAE) in treating renal angiomyolipomas (AMLs) in both elective and emergency settings. Between October 1988 and September 2008, 27 patients (28 renal units) were treated with SAE, either on an emergency basis for 15 (53.6%) bleeding AMLs or prophylactically for 13 (46.4%) asymptomatic high-risk (size >4.1 cm) AMLs. Six males and 21 females with a mean age of 46.3 years (range, 26-68) were followed for a mean period of 7.1 years (range, 1.3-20.2) for recurrence of symptoms, need for re-embolization, or need for renal surgery. SAE outcome was evaluated using the Kaplan-Meier method. Predictor(s) of outcome were identified with univariate analysis by log-rank test. Mean size of AMLs was 10.9 cm (range, 4-30). Eight (29.6%) patients had bilateral and 19 (70.4%) had unilateral AMLs. Seventeen (60.7%) kidneys had solitary AMLs; 11 (39.2%) kidneys had multicentric AMLs. Of the 15 bleeding AMLs, 12 (80%) patients required a blood transfusion. Twenty-six (93%) AMLs were successfully embolized in the first SAE. During follow-up, four (14.8%) patients required re-embolization. Renal surgery was required in four (14.8%) patients. From the Kaplan-Meier analysis, the overall renal surgery sparing rate at 5 years was 85% (95% CI: 71-99%), whereas the single session SAE success rate at 5 years was 63% (95% CI: 42-84%). Of all the variables, only AML >10 cm was significantly associated with the subsequent need for renal surgery (P = .03). No renal malignancy was noted at final follow-up. SAE is effective and durable in preventing large AMLs from bleeding, treating AMLs presenting with bleeding, and sparing the need for renal surgery.