Flexible ureteroscopy with a flexible and navigable suction ureteral access sheath versus mini-percutaneous nephrolithotomy for renal stones larger than 2 cm in patients with a solitary kidney: a propensity score-matched and win ratio analysis.

OBJECTIVE

To compare the efficacy and safety of flexible ureteroscopy using a flexible and navigable suction ureteral access sheath (FANS f-URS) with mini-percutaneous nephrolithotomy (mini-PCNL) for > 2 cm renal stones in patients with a solitary kidney.

METHODS

This retrospective study included patients with a solitary kidney and renal stones > 2 cm who underwent either FANS f-URS or mini-PCNL between July 2023 and January 2026. Propensity score matching (PSM) was performed in a 1:2 ratio. The primary analysis consisted of a pair-matched win ratio analysis using a hierarchical composite endpoint comprising postoperative complications, 1-month stone-free rate (SFR), and length of postoperative hospital stay. Perioperative outcomes and postoperative complications were also compared between the two groups.

RESULTS

After PSM, 88 patients were included (41 FANS f-URS and 47 mini-PCNL). In the win ratio analysis, FANS f-URS demonstrated significantly greater overall clinical benefit than mini-PCNL (win ratio = 4.12, 95% CI 1.50-21.02, p < 0.001). Although mini-PCNL achieved a significantly higher immediate SFR, the 1-month SFR was comparable between the two groups after second-stage treatment. Compared with mini-PCNL, FANS f-URS was associated with significantly lower postoperative morbidity, reduced hemoglobin decrease, shorter hospitalization, lower postoperative pain scores, and greater improvement in quality of life.

CONCLUSIONS

In patients with a solitary kidney and renal stones > 2 cm, a staged FANS f-URS strategy achieved a 1-month SFR comparable to that of mini-PCNL while offering a lower risk of complications and improved postoperative recovery. FANS f-URS may represent a safer and less invasive treatment strategy for this high-risk population.