Pushing the Envelope: Ambulatory Percutaneous Nephrolithotomy for Patients with Complex Renal Calculi

Introduction: Ambulatory percutaneous nephrolithotomy (PCNL) has grown in popularity for patients with smaller stone burdens and few comorbidities. Its feasibility in patients with complex renal calculi is less clear. In this study, we evaluate the safety of same-day discharge after PCNL for patients with complex renal stones when compared with those admitted after surgery. Methods: We retrospectively identified adult patients who underwent PCNL for complex stones from April 2019 to January 2021 at our institution. Our practice of routinely admitting patients was changed in October 2020 largely out of necessity amid the COVID-19 pandemic. Accordingly, all PCNL patients before this practice change were admitted, whereas those treated after were intended for same-day discharge. Patients were considered to have complex stones with either a Guy's Stone Score ≥3 or STONE nephrolithometry score ≥9. Baseline characteristics and rates of postoperative day 1 (POD#1) complications, 30-day complications, 30-day readmissions, and 30-day emergency department (ED) visits, as well as stone-free rates (SFRs) were compared between ambulatory and admitted patients. Results: Seventy-nine ambulatory and 111 admitted patients with complex renal calculi were included. Only one intended ambulatory patient required admission. The frequency of 30-day postoperative complications (ambulatory = 20.3%, admitted = 25.2%, p = 0.423) and POD#1 complications (ambulatory = 1.3%, admitted = 7.2%, p = 0.083) was lower among ambulatory patients, but these differences were not significant. Compared with admitted patients, the likelihood of an ED visit without readmission was significantly higher for ambulatory patients (8.9% vs 1.8%, p = 0.024), but the likelihood of readmission was lower (5.1% vs 9.9%, p = 0.222). Computed tomography-determined SFRs were similar (zero fragment rate 80.6% [ambulatory] vs 70.6% [admitted], p = 0.710). Conclusions: Same-day discharge and admitted patients demonstrate similar safety profiles and SFRs after PCNL of complex renal calculi without increased risk of readmission, suggesting that ambulatory PCNL is feasible for selected higher-risk patients.