Renal angiomyolipoma: Selective arterial embolization-effectiveness and changes in angiomyogenic components in long-term follow-up

PURPOSE: To evaluate the efficacy of selective arterial embolization in symptomatic renal angiomyolipoma (AML) and the change in angiomyogenic components during long-term follow-up after embolization. MATERIALS AND METHODS: Fourteen adult patients with symptomatic AMLs underwent 16 selective arterial embolizations. The embolic materials used were absolute alcohol with (n = 5) or without (n = 3) iodized oil, Gianturco coils (n = 4), and polyvinyl alcohol foam powder with gelatin sponge (n = 2). Follow-up ultrasonography and computed tomography (CT) were performed in six and 14 patients, respectively. The effectiveness of selective arterial embolization was evaluated on the basis of the area of the angiomyogenic components in the AML on initial and follow-up images and clinical improvement. RESULTS: All patients showed devascularization of the tumor on the postembolization angiograms. In 13 patients, clinical symptoms disappeared. The follow-up period was 7-72 months (mean, 33 months). One patient underwent nephrectomy at 7 months after embolization because of a large cystic lesion found at 1 month. In long-term CT follow-up (greater than or equal to 12 months) in 12 patients, nearly all angiomyogenic components disappeared, but fatty components partially shrank with liquefactive necrosis in tumors. CONCLUSION: Selective arterial embolization is an effective and safe treatment of AML. The angiomyomatous components crucial for the prevention of bleeding were very sensitive to the embolization.