Radiofrequency ablation (RFA) therapy for renal angiomyolipoma (AML): an alternative to angio-embolization and nephron-sparing surgery

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? The natural history of renal angiomyolipomas (AML) shows increasing size and increasing risk of haemorrhage. For those patients undergoing treatment, extirpative surgery or renal angio‐embolization has increased morbidity. Due to its haemostatic effect, radio‐frequency ablation (RFA) may be used safely and effectively for the treatment of small (<4 cm), symptomatic renal AML. This study represents the largest case series reporting on RFA for renal AML.

OBJECTIVES

? To show that radiofrequency ablation (RFA) is safe and effective treatment for renal angiomyolipoma (AML). ? Current treatments to reduce the risk of haemorrhage include tumour extirpation, angio‐embolization, or ablative therapy.

PATIENTS AND METHODS

? Review of our prospective database revealed 15 patients with intraoperative biopsy confirmed renal AML undergoing RFA from February 2002 to March 2010. ? Patients underwent either laparoscopic or computed tomography (CT)‐guided percutaneous RFA using either the Cool‐tip? (Covidien, Inc. Boulder, CO, USA) or RITA? (Angiodynamics®, Latham, NY, USA) RFA probe. ? CT at 1 month, 6 months, 1 year, and annually thereafter.

RESULTS

? In all, two male and 13 female patients with seven left‐sided and eight right‐sided tumours with a mean (range) size of 2.6 (1.0–3.7) cm underwent laparoscopic (five) or CT‐guided (10) RFA. ? No intraoperative complications occurred. Minor complications included transient haematuria and intercostals nerve transection. Surgical complications included pneumonia and myocardial infarction. ? There was no radiographic evidence of persistent AML (CT enhancement) at a mean follow‐up of 21 months.

CONCLUSIONS

? The haemostatic effect of RFA allows renal lesions suspicious for AML to be treated without bleeding complications. ? Avoids surgical risk of extirpation or embolization. ? RFA for renal AML is safe and effective.