The efficacy, safety and durability of selective renal arterial embolization in treating symptomatic and asymptomatic renal angiomyolipoma.

OBJECTIVE: To review the long-term outcome of selective renal arterial embolization (SAE) in treating renal angiomyolipomas (AMLs) in both elective and emergency settings.
MATERIALS AND METHODS: 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.
RESULTS: 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.
CONCLUSIONS: SAE is effective and durable in preventing large AMLs from bleeding, treating AMLs presenting with bleeding, and sparing the need for renal surgery.