BERKELEY, CA (UroToday Inc.) - In the era of contemporary imaging, the majority of renal angiomyolipomas (AMLs) may be diagnosed noninvasively with CT or MR criteria alone. Due to the risk of spontaneous hemorrhage, treatment is typically recommended for patients with renal AMLs larger than 4 cm (Oesterling et al, J Urol 1986 Jun;135(6):1121-4). While selective angioembolization has been proven to be safe, no studies to date had previously evaluated its long-term efficacy.

Kothary, Soulen and associates from the University of Pennsylvania retrospectively evaluated their experience treating 30 renal AMLs found with selective arterial embolization over a 10-year period within 19 patients. Ten patients had multiple AMLs associated with Tuberous Sclerosis (TS) and 9 patients presented with solitary lesions. Embolization was performed with use of ethanol mixed with iodized oil (Ethiodol) in 29 tumors and with the addition of coils in 1 case. All tumors were completely embolized according to angiographic criteria including vascular stasis and absence of arterial feeders. While there were no major complications, 4 patients required repeat embolization for recurrent symptoms, including bleeding in 1 patient. Recurrence was assessed radiographically after a mean follow-up of 51 months, using an increase in mass size greater than 2 cm. as the criterion for recurrence.

After successful selective embolization of all masses, the overall recurrence rate for patients was 32% and 30% for masses. While no patients with sporadic AMLs recurred, this was not true for 60% of patients with TS, in whom 43% (9) of 21 renal masses demonstrated recurrence. The median time interval from embolization to recurrence was 6.5 years, with recurrences occurring as late as 11 years after treatment.

In patients with sporadic AMLs, selective angioembolization provides long-term sustained freedom from recurrence. However, patients with TS and multiple AMLs continue to represent a therapeutic challenge for the urologist, with recurrence rates as high as 60%. Nevertheless, selective angioembolization appears to be safe in this cohort, providing on average long intervals between recurrences. The question remains whether selective angioembolization maximally preserves normal renal parenchyma when compared with newer percutaneous and laparoscopic ablative techniques such as cryoablation, radiofrequency ablation or partial nephrectomy.

J Vasc Interv Radiol. 2005 Jan;16(1):45-50