Comparison of the efficacy and safety of flexible vacuum-assisted ureteral access sheath-assisted flexible ureteroscopic lithotripsy, conventional ureteral access sheath-assisted flexible ureteroscopic lithotripsy, and mini-percutaneous nephrolithotomy for 2-3 cm renal stones.

BACKGROUND: The optimal management of 2-3 cm renal stones remains challenging because effective stone clearance must be balanced against perioperative morbidity. Mini-percutaneous nephrolithotomy (mPCNL) provides high stone-free rates (SFR) but is associated with greater procedural burden, whereas flexible ureteroscopic lithotripsy (fURL) is less invasive but may be limited by fragment clearance efficiency. A flexible vacuum-assisted ureteral access sheath (FV-UAS) has recently been introduced to facilitate fragment evacuation and improve intrarenal drainage during fURL.

OBJECTIVES: To compare the efficacy and safety of FV-UAS-assisted fURL, conventional ureteral access sheath-assisted flexible ureteroscopic lithotripsy (UAS-assisted fURL), and mPCNL for the treatment of 2-3 cm renal stones, and to provide evidence for surgical decision-making in this clinical setting.

DESIGN: This was a retrospective single-center comparative study.

METHODS: This retrospective study included 156 patients with 2-3 cm renal stones who underwent FV-UAS-assisted fURL (FV-UAS group, n = 50), UAS-assisted fURL (UAS group, n = 54), or mPCNL (mPCNL group, n = 52) at Xi'an People's Hospital between June 2022 and December 2024. Perioperative outcomes were compared, including operative time, postoperative hemoglobin decrease, postoperative pain assessed by the visual analogue scale (VAS), postoperative length of hospital stay, total hospitalization costs, and postoperative adverse events, including fever, renal colic, urinary tract infection, and steinstrasse. SFR was assessed on postoperative day 3 and at 1 month postoperatively.

RESULTS: Operative time differed significantly among the three groups (FV-UAS 77.56 ± 15.04 min vs mPCNL 67.60 ± 10.44 min vs UAS 85.04 ± 15.78 min; p < 0.05). Postoperative hemoglobin decrease was significantly lower in the FV-UAS and UAS groups than in the mPCNL group (3.50 ± 2.40 g/L and 4.01 ± 2.14 g/L vs 13.86 ± 3.21 g/L; p < 0.001). The postoperative length of stay was shorter in the FV-UAS group than in the UAS group and markedly shorter than in the mPCNL group (3.04 ± 0.73 d vs 3.52 ± 0.72 d vs 6.04 ± 0.86 d; p < 0.05). Postoperative VAS scores were lower in the FV-UAS and UAS groups than in the mPCNL group (p < 0.05), with no significant difference between the two fURL groups. Regarding total hospitalization costs, the mPCNL group had the lowest costs, and the FV-UAS group had lower costs than the UAS group (p < 0.05). The overall adverse event rates were comparable among groups. Steinstrasse occurred in three cases, all in the UAS group. On postoperative day 3, SFRs were 94.0% (FV-UAS), 75.9% (UAS), and 80.8% (mPCNL), with the FV-UAS group higher than the UAS group (p < 0.05). At 1 month, SFRs were 96.0% (FV-UAS), 81.5% (UAS), and 96.2% (mPCNL), with both the FV-UAS and mPCNL groups higher than the UAS group (p < 0.05).

CONCLUSION: For 2-3 cm renal stones, FV-UAS-assisted fURL was associated with less hemoglobin decrease, lower postoperative pain, and shorter hospital stay than mPCNL, and showed advantages over UAS-assisted fURL in operative time and hospitalization costs, while achieving a 1-month SFR comparable to mPCNL. FV-UAS-assisted fURL may represent a safe and effective minimally invasive alternative for 2-3 cm renal stones.

TRIAL REGISTRATION: Not applicable.