Renal angiomyolipoma: long-term results following selective arterial embolization

The treatment for and long-term outcome of renal angiomyolipoma (AML) at high-risk for bleeding has not been determined.

To evaluate the complication rates and the long-term outcomes among patients treated by selective arterial embolization (SAE) for a large or symptomatic renal AML.

Forty-one patients with 48 kidneys containing AML were treated by SAE at a single tertiary academic center.

All patients were treated by SAE and followed in a single center.

SAE was performed with a mixture of 96% ethanol and polyvinyl alcohol particles. The variables used for the analysis included age, gender, presence of tuberous sclerosis (TS), and maximal tumor size prior to SAE. The study end points were recurrence of symptoms or bleeding, the need for re-embolization or surgery, and disease-specific survival. The mean follow-up period for the entire group was 4.8 yr.

Mean patient age was 51 yr (range: 24-82), and the mean initial tumor size was 10.3 cm. Successful SAE was achieved in 40 patients (91%) with a minor complication rate of 11%. Avoidance of surgery was achieved in 96% of the kidneys. No retroperitoneal hemorrhage was noted during follow-up, and 98% of the kidneys were preserved during the follow-up period. No significant changes in creatinine levels were noted following SAE (P=0.27). The freedom from surgical treatment at 5 yr following SAE was 94% (95% CI, 89-99%). Disease-specific survival of the entire cohort was 100%. The study is a retrospective, and treatment was not given according to prospective protocol, and therefore sample bias may be present.

SAE of renal AML has long-term efficacy in preventing hemorrhagic complications of renal AML, and preservation of the involved kidneys is amenable in both TS and sporadic cases.