Comparison of ultrasonic lithotripsy with Ho:YAG laser lithotripsy during percutaneous nephrolithotomy for 20-40 mm low-hardness renal calculi: a propensity score-matched study.

PURPOSE: This study aims to compare the efficacy and safety of ultrasonic lithotripsy (UL) with an integrated suction system versus holmium: yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy during percutaneous nephrolithotomy (PCNL) for treating 20-40 mm low-hardness renal stones using propensity score matching (PSM) analysis. METHODS: This single-center retrospective cohort study included 436 patients undergoing PCNL for 20-40 mm low-hardness stones. PSM balanced baseline characteristics, comparing patients treated with an ultrasonic lithotripsy system equipped with an integrated suction system (UL group, n = 110) and Ho:YAG laser lithotripsy (Ho:YAG group, n = 110) regarding 1-day/1-month stone-free rates (SFR), operative time, and complications. RESULTS: The UL group exhibited a significantly higher 1-day SFR (96.36% vs. 85.45%, P = 0.005). The 1-month SFR was numerically higher in the UL group than in the Ho:YAG group (96.36% vs. 90.00%), although the difference did not reach statistical significance (P = 0.061). Complication rates were lower in the UL group (7.27% vs. 22.73%, p = 0.001), particularly for low-grade Clavien I-II events. Postoperative pain (VAS) at 6 h was higher in the UL group (7.24 ± 1.53 vs. 6.67 ± 1.97, p = 0.018), yet comparable at 24/48 hours. Hemoglobin drop, operative time, and hospitalization showed no intergroup differences. CONCLUSION: UL demonstrates superior early SFR and safety for 20-40 mm low-hardness stones, suggesting that it has the potential to facilitate stentless PCNL. Prospective studies are warranted to validate these findings and optimize clinical protocols.