Comparison of vacuum-assisted flexible ureteroscopy and percutaneous nephrolithotomy for 2-3 cm upper tract stones: a...

This real-world study aimed to compare the perioperative and recovery outcomes of single-use digital flexible ureterorenoscopy with a flexible-tip vacuum-assisted ureteral access sheath (FV-UAS) against standard percutaneous nephrolithotomy (PCNL) for managing upper urinary tract stones measuring 2-3 cm.

This single-center, retrospective cohort study enrolled 116 patients (69 FV-UAS, 47 PCNL) between January 2023 and December 2024. The co-primary outcomes were the stone-free rate (SFR) on postoperative day 1 and at 1 month. The SFR on postoperative day 1 was assessed by kidney-ureter-bladder (KUB) radiography or ultrasound, while the SFR at 1 month was assessed by non-contrast computed tomography (NCCT). Secondary outcomes included operative time, length of hospital stay (LOS), hydronephrosis resolution at 90 days, complication rates, and trends in serum creatinine and neutrophil-to-lymphocyte ratio (NLR).

Baseline characteristics were comparable. While the FV-UAS group demonstrated a numerically higher immediate SFR (92.75% vs. 76.59%, P = 0.0132), this finding should be interpreted as exploratory due to the limited sensitivity of KUB/ultrasound for early residual fragment detection. The stone-free rate at 1 month, assessed by NCCT, was excellent and comparable between groups (98.55% vs. 91.49%, P = 0.1564). Operative time (64.0 ± 9.3 vs. 72.3 ± 8.8 min, P = 0.0048) and LOS (3.5 vs. 6.2 days, P < 0.0001) were shorter in the FV-UAS group, which also had lower peak postoperative pain scores and body temperature. The rise in serum creatinine was slightly lower in the FV-UAS group, though the clinical significance of this small absolute difference is uncertain. The overall complication rate (Clavien-Dindo Grade I-V) was markedly lower for FV-UAS (10.1% vs. 40.4%, P < 0.001). Rates of complete hydronephrosis resolution at 90 days were comparable (94.20% vs. 87.23%, P = 0.3863).

In this real-world study, the FV-UAS technique for 2-3 cm upper tract stones was associated with comparable outcomes and stone clearance compared to PCNL. It offered excellent stone clearance, faster recovery, reduced postoperative pain and inflammation, and a more favorable safety profile, particularly regarding bleeding. FV-UAS represents a compelling minimally invasive alternative for selected patients in this stone size category.