Varying Outcomes among Patients with Large Angiomyolipomas according to the Treatment Method

Purpose: This study aimed to evaluate the outcomes of large angiomyolipoma (AML) treatment by selective arterial embolization (SAE) versus nephron-sparing surgery (NSS) using a robotic surgical system. Materials and Methods: Between January 2011 and June 2018, we retrospectively reviewed 25 patients who underwent robot-assisted partial nephrectomy (RAPN) or SAE for large AMLs. Ten patients underwent RAPN, and 15 underwent SAE. Patient demographics, AML characteristics, and operative and postoperative clinical outcomes were recorded and analyzed. Outcomes were compared between patients who underwent RAPN and patients who underwent SAE. Specifically, changes in renal function and size were evaluated after the treatment. Results: The mean age of the patients was 52.9 years, and 22 of 25 patients were female. The mean maximum AML diameter on computed tomography was 8.9 cm, and 8 patients had multiple masses. Twenty-two of 25 patients had moderate to high RENAL complexity. Patients who underwent SAE had more symptoms (p = 0.018) and higher RENAL complexity scores (p = 0.013) on average. On average, tumor size decreased by 99% among RAPN patients and by 58% among SAE patients (p = 0.001). Although the mean pretreatment estimated glomerular filtration rate (eGFR) was higher among RAPN patients (99.8 vs. 80.0 mL/min/1.73 m 2 , p = 0.043), there were no significant changes in eGFR in either group after the treatment. One patient in the RAPN group experienced complications, but the postoperative ileus resolved without intervention. Conclusions: Both RAPN and SAE were effective and feasible treatment options for large AMLs. The AML characteristics and the condition of the patient might be important in determining the appropriate treatment method.