Advancements in Performance of Percutaneous Nephrolithotomy in Ambulatory Surgery Centers: Outcomes and Lessons From 1250+ Cases

Abstract

ObjectiveTo evaluate the safety and efficacy of routine ambulatory percutaneous nephrolithotomy in a freestanding ambulatory surgical center. MethodsPatients were treated between 2015-2022 by one of three experienced endourologists in Maryland. The surgery center is free-standing, with the nearest hospital approximately 10 minutes away. Patient characteristics and surgical datapoints, including need for transfer, were gathered prospectively at the time of surgery. Subset analyses were performed in patients with staghorn calculi or elevated body mass index, as they represent higher risk populations. ResultsA total of 1267 patients underwent ambulatory percutaneous nephrolithotomy with a median stone diameter of 32mm. The average recovery time was 87 minutes, with 1.7% of patients requiring transfer to the hospital, generally for postoperative hypotension or inadequate pain control. 166 patients with body mass index >40 were safely treated, with no significant difference in transfer rate (p=0.5). 2.8% of patients had a complication, with the majority being Clavien-Dindo grade I or II. 88 patients with staghorn calculi were treated, with a 6% transfer rate. Staghorn calculi were the only factor found on multivariable analysis to be a significant predictor of transfer (OR 3.56 (1.17-10.82) p<.05). ConclusionsAmbulatory percutaneous nephrolithotomy may safely be performed in a surgery center in most patients. These outcomes reflect the real-world experience of high-volume surgeons and demonstrate a multi-year paradigm shift in percutaneous nephrolithotomy from an inpatient procedure to an outpatient procedure in a surgery center.