Outpatient versus inpatient flexible ureteroscopy with flexible and navigable suction access sheath: A multicenter comparative analysis of perioperative outcomes from the flexible and navigable access sheath collaborative study group.

OBJECTIVE: To evaluate the clinical effectiveness and safety of outpatient versus inpatient flexible ureterorenoscopy (FURS) using the flexible and navigable suction access sheath (FANS). METHODS: Conducted across 25 global centers between July 2023 and March 2024, this study included patients undergoing retrograde intrarenal surgery stratified by surgical setting. All patients were counseled for FURS with FANS as an outpatient procedure unless otherwise planned earlier. The primary outcome was stone-free rate defined as zero residual fragments or a single fragment of ≤2 mm on a 30-day non-contrast CT scan. The secondary outcome was complication rates. Outpatient status applied to any patient observed for less than 24 h postoperatively. No fixed criteria were assigned for outpatient care. RESULTS: Seven hundred and four patients were included, with 356 undergoing outpatient surgery and 348 receiving inpatient care. Operative, lasing, and ureteroscope times were significantly shorter in the outpatient group (p<0.001 in all three), despite the larger stone burden in the outpatient group. A significantly higher number of patients had intraoperative residual fragments in the inpatient group. The outpatient group achieved a significantly higher 100% stone-free rate (67% vs. 53%, p<0.001). A significantly greater proportion of the outpatient cohort underwent placement of an overnight ureteral catheter (p<0.001), which was subsequently removed at discharge, whereas the majority of the inpatient group received a double-J stent (p<0.001). Reintervention and intraoperative complication rates were comparable between groups. Postoperative complications were fewer in outpatient patients: fever (0.84% vs. 3.2%, p=0.02). The multivariate analysis identified postoperative double-J stent positioning as the factor associated with lower odds of having postoperative fever requiring antibiotics (odds ratio 0.282, 95% confidence interval 0.109-0.729, p=0.009). CONCLUSION: Outpatient FURS with FANS demonstrates excellent outcomes, with a low rate of minor complications. These findings support the broader adoption of outpatient RIRS in patients with kidney stones and normal renal anatomy, provided that patient selection and intraoperative planning are appropriately optimized.