Outpatient Percutaneous Nephrolithotomy: The UC San Diego Health Experience

Introduction: Outpatient percutaneous nephrolithotomy (PCNL) has been described for highly selected patients. We sought to assess the safety and feasibility of outpatient PCNL in a tertiary referral stone center without strict patient selection criteria.Materials and Methods: We reviewed all PCNLs performed at our institution from September 2015 to October 2016. Of the 97 eligible cases, 60 patients underwent planned outpatient PCNL. Primary outcome was complication rate, and secondary outcome determined predictor variables of inpatient admission. Results: Thirty-seven inpatient and 60 planned outpatient (one bilateral) PCNLs were performed with 65% and 44% American Society of Anesthesiologists (ASA) score 3, respectively. The 30-day overall complication rate for the inpatient and planned outpatient groups was 27% and 20%, respectively (p=0.43) [70% and 92% Clavien grades I-II]. Emergency department presentation within 30 days was 19% and 18% (p=0.94), and unplanned hospital readmission rate was 3% and 10% (p=0.05). The 37 inpatient PCNL patients had larger total stone burden than outpatient cases (40.7 vs 25.8mm, p=0.0014); more often required two or more punctures into the kidney during the procedure (73% vs 45%, p=0.025); and more often had supracostal access (20% vs 7%, p=0.05). For the outpatient PCNL cohort, 72% patients were discharged same day, 28% were observed overnight for refractory symptoms or social reasons. Outpatient cohort radiographic stone-free rate by CT (no stones) was 67%. Conclusion: Outpatient PCNL has been safely and effectively performed within our institution in moderate-sized stones almost regardless of comorbidity status. We suggest that this approach is a potential algorithmic change in centers with sufficient case volume.