BERKELEY, CA (UroToday.com) - Complications from renal angiomyolipomas (AMLs) are common in patients with tuberous sclerosis complex (TSC) and tumors greater than 4 cm are more likely to cause symptoms. Larger AMLs typically become more vascular and may develop multiple tortuous vessels and aneurysms that are prone to rupture. AMLs occur in up to 80% of older children and adults with TSC and are the most common cause of death in adults with TSC. Current treatment options for AMLs include observation, surgery (partial or total nephrectomy), or transcatheter tumor embolization.

A recent paper by D. H. Ewalt and colleagues from a multicenter group from Texas and Wake Forest reviews long-term experience with transcatheter tumor embolization as a definitive treatment for AMLs due to TSC. The manuscript is published in the November 2005 issue of the Journal of Urology. In the review, 16 patients underwent 18 treatment sessions to embolize 27 tumors whose size ranged from 4 to 21 cm in diameter. All patients had at least three years of follow-up and most had imaging which consisted of CT or MRI at 3 months post treatment with periodic imaging and office visits afterwards.

Analysis of the results shows that all patients had successful embolization of the AML with minimal loss of surrounding normal parenchyma. One to 5 feeding arteries were treated to fully embolize the tumors. Eight patients had embolizations of more than one AML in the same kidney during the same procedure. There were no instances of intraoperative hemorrhage of delayed AML rupture. All patients were observed in the hospital for signs of post-embolization syndrome, and 11 individuals were hospitalized for 2 to 7 days with a variable pattern of pain, nausea and vomiting, or fever (maximum 39.6C). The severity of the post-embolization syndrome was unrelated to the number or size of the treated lesions.

The thirteen patients who underwent renal imaging 3 months after the procedure demonstrated decreased size of the embolized AML. Those patients with more fat content within the AML (as shown by pretreatment CT scan) had a less obvious reduction in the size of the tumor. Creatinine values remained normal in all 9 individuals for whom information was available. None of the patients developed renal failure or required secondary renal surgery following treatment. Follow-up imaging, done 3 to 9 years after treatment, has not demonstrated regrowth of the embolized AML.

The authors suggest that due to the safety and efficacy of transcatheter selective embolization, the procedure should be considered the initial treatment of choice for large or symptomatic renal angiomyolipomas presenting in individuals with tuberous sclerosis. The post-embolization syndrome, while unpredictable in its appearance, is self-limiting.

J Urol. 2005 Nov; 174(5):1764-6