Comparison between Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopy for Patients with Upper Calyceal Calculi Larger than 2 cm.

Background: This study aimed to compare the results of flexible ureteroscopy with holmium laser lithotripsy (FURSL) and mini-percutaneous nephrolithotomy (mini-PNL) for the treatment of >2 cm upper calyceal stones.

Methods: The data of patients who underwent FURSL and mini-PNL surgery for kidney stones between May 2011 and June 2023 were retrospectively examined. Patients with single or multiple kidney stones located in the upper calyx and varying in diameter from 2 cm to 4 cm were included in the study. Operation time, hospitalisation time, complication rates and 1 month stone-free rate (SFR) were compared between the two surgical methods. Stone-free status was evaluated by performing non-contrast computed tomography 1 month after the surgery.

Results: A total of 73 (49.3%) and 75 (50.7%) patients were included in the FURSL and mini-PNL groups, respectively. The mean operation time (72.5 vs. 89.7 min) and hospital stay (1.2 vs. 2.1 days) were shorter in the FURSL group (p < 0.001). Although complications were less common in the FURSL group, the difference was not statistically significant (12.3% vs. 21.3%, p = 0.199). The 1 month SFRs were 83.6% and 90.7% in the FURSL and mini-PNL groups, respectively, without statistically significant difference between the groups (p = 0.461).

Conclusions: Both surgical approaches are equally effective and safe for the treatment of >2 cm upper calyceal stones. Short surgery and hospitalisation times are the most important advantages of FURSL. This type of surgery can be recommended as an alternative treatment to mini-PNL, with lower complication rates in selected patients.