V3-12: Robot Assisted Partial Nephrectomies – 12 Tumors, 1 Kidney
Tuberous sclerosis is a rare hereditary disorder caused by the decrease or loss of expression of the TSC1 or TSC2 tumor suppressor gene, resulting in an increase in activation of the mTOR pathway. Renal angiomyolipomas (AMLs) occur in up to 60% of patients with tuberous sclerosis. The risk of hemorrhage from AMLs increases with tumors larger than 4 centimeters. Elective AML treatment includes arterial embolization, ablation or nephron-sparing excision, if possible. Everolimus, an mTOR inhibitor, is FDA approved to reduce angiomyolipoma size in patients with tuberous sclerosis. We hypothesize that Everolimus may decrease the vascularity of the tumors and help minimize bleeding during surgery.
An 18 year-old female was referred to our clinic for evaluation of multiple bilateral angiomyolipomas. She had been on Everolimus for several years and had undergone several unsuccessful embolizations at an outside facility. MRI of the abdomen showed more than 30 angiomyolipomas in the left kidney and more than 20 in the right kidney. The largest tumors in the left kidney measure 4 centimeters, 2.7 centimeters, and 2 centimeters. A renal scan indicated relatively equal kidney function. The patient went to the operating room for robot assisted left partial nephrectomies. Twelve tumors were enucleated without hilar clamping. The 2 largest tumor defects were closed with a sliding clip technique renorrhaphy. Hemostatic matrix was placed for additional hemostasis. Total operative time was 3 hours and total robot console time was 2.5 hours.
Twelve tumors were excised with the largest measuring almost 5 centimeters. There were no intraoperative or postoperative complications. Her hemoglobin nadir was 10.2 g/dL from a preoperative value of 11.7 g/dL. Postoperatively her creatinine stayed stable at 0.6 mg/dL. She was discharged home on postoperative day 2.
Robot partial nephrectomies for multiple angiomyolipomas is a feasible, safe, and effective option in patients with tuberous sclerosis who wish to preserve renal function while pursuing surgical management. Everolimus may contribute to the lack of vascularity noted in these lesions with minimal bleeding during surgery.