A prospective, randomized study comparing the efficacy of miniaturized percutaneous nephrolithotomy and retrograde intrarenal surgery in treatment of 10 to 20 mm, lower calyceal, high-density renal stones

Abstract Background To evaluate the safety and effectiveness of mini-PCNL and RIRS for the treatment of lower calyceal high-density renal stones measuring 10–20 mm. Methods This prospective, randomized, open-label, comparative trial was conducted between April 2022 to August 2024 on 170 patients with lower calyceal, high density renal stones 10–20 mm. Patients were randomly divided into two groups: Group 1 managed by mini-PCNL, and Group 2 managed by RIRS. Outcome measures including stone-free rate (SFR), operative, fluoroscopy, and hospitalization times, rehospitalization, retreatment rate, and intra- and post-operative complications were compared between groups. Results There were no significant differences in preoperative baseline data between groups. Stone characteristics included mean stone size (15.46 ± 2.56 mm vs. 14.55 ± 2.43 mm, p = 0.122) and density (1426.83 ± 229.17 HU vs. 1343.76 ± 192.72 HU, p = 0.113) for mini-PCNL and RIRS groups, respectively. Mean operative time (81.79 ± 17.88 vs. 72.11 ± 15.99 min, p < 0.001), fluoroscopy time (3.18 ± 1.2 vs. 1.22 ± 0.95 min, p < 0.001), and hospitalization time (54.49 ± 18.64 vs. 28.27 ± 6.59 h, p < 0.001) were significantly different between mini-PCNL and RIRS groups, respectively. The SFR was numerically higher in mini-PCNL (93.83%) compared to RIRS (87.95%), but this difference was not statistically significant ( p = 0.192). Conclusions Treatment of 10–20 mm lower calyceal, high-density renal stones can be effectively and safely accomplished with either mini-PCNL or RIRS. While mini-PCNL achieved numerically higher SFR and decreased rates of retreatment and rehospitalization, it was associated with increased blood loss. RIRS offers advantages, including shorter operative time, reduced fluoroscopy exposure, and shorter hospital stays.