Laparoscopic Cryoablation of Renal Angiomyolipoma

Abstract

Angiomyolipomas are rare benign renal tumors which occasionally require intervention. Preservation of renal function is essential when treating renal angiomyolipoma in patients with multiple or bilateral lesions. We report on the first series of patients with renal angiomyolipoma treated with laparoscopic cryoablation. Seven patients with pathologically confirmed renal angiomyolipoma underwent laparoscopic cryoablation. Transperitoneal surgery with intraoperative ultrasound was performed, followed by clinical monitoring with creatinine and axial imaging. Mean patient age was 44.9 years. Six patients were female, and 2 patients had associated tuberous sclerosis and multiple bilateral angiomyolipoma. In 1 patient 5 lesions were treated, in another 3 lesions were treated and in the remaining patients solitary lesions were treated. The average size of the largest lesion in each patient was 4.2 cm (range 2.5 to 7.0). The procedures were tolerated well with 3 minor complications in 2 patients. Average operative time was 170 minutes (range 137 to 232) and decreased as expertise was gained. Average estimated blood loss was 116 cc (range 15 to 250). Renal function was preserved, with mean preoperative and postoperative creatinine 0.83 (range 0.6 to 1.6) and 0.91 (range 0.7 to 1.8), respectively. Average decrease in estimated creatinine clearance was 8.6 ml per minute. Followup imaging using computerized tomography or magnetic resonance imaging showed reduction in lesion size, lack of blood flow and no subsequent regrowth in all patients. Laparoscopic cryoablation is a safe and feasible minimally invasive, nephron sparing alternative for the treatment of angiomyolipoma.