Session: MP35: Stone Disease: Surgical Therapy (including ESWL) II
MP35-18: Mini-percutaneous nephrolithotomy versus standard percutaneous nephrolithotomy for the management of 20- to 40-mm renal calculi : safety and efficacy
Introduction: The incidence of small and medium-sized stones is rising. A list of minimally invasive approaches is available and urologists must choose the best therapeutic option to ensure complete stone clearance with less morbidity. Initially, mini-percutaneous nephrolithotomy (mPCNL) was developed to manage renal stones in pediatric patients. Then, this approach has become a frequent treatment modality even in high stone burden. Although an increasing number of studies have been published on mPCNL, randomized clinical studies are rare. We conducted this study to assess the safety and the effectiveness of mPCNL versus sPCNL. Methods: We conducted a prospective randomized study between September 2018 and April 2021 including all patients with a 20 to 40 mm kidney stone managed by percutaneous approach. Exclusion criteria were pediatric population, abnormal coagulopathy state, abnormal renal anatomy and multiple-tract percutaneous access. All procedures were performed by the same surgeon in the supine position. In all, 110 patients were randomized into two groups: Group A: 59 patients underwent sPCNL using a 24Fr nephroscope through a 30 Fr sheath; and group B: 51 patients underwent mPCNL procedure using minimally invasive PCNL system: 12Fr nephroscope with a 16,5/17,5 Fr sheath after a single-step dilatation. For both groups, demographic data, stone characteristics, operative data, and postoperative data were recorded prospectively. All patients were evaluated with a non-contrast spiral CT 1 month after the operation, to determine the final stone-free status. Statistic evaluation was performed using Student's t test. Results: The mean age was 51.1±12.2 and 44.4±16.3 years for sPCNL group and mPCNL group, respectively. The median stone size was 33.1±9.8 mm for group A and 28.8±11.2 mm for group B. The operative time was higher in group B (135±57.8 min vs 110±41.1min, p=0.033). According to Clavien–Dindo classification, no statistical difference was detected between the groups in terms of complication rates (p=0.09). However, the rates of hemoglobin drop and transfusion rates were significantly higher in sPCNL than mPCNL(1.53g-dL vs. 0.73 g-dL, p<0.015). Only one patient required transfusion in group B compared with six patients in group A. The hospital stay was found to be significantly shorter in the mPCNL group (2.75±0.7 vs. 3.8±1.1days, p=0.02). The success rate in the sPCNL group was higher than mPCNL group in terms of stone clearance after 1 month, but this difference was statistically insignificant (88.2 vs. 86%, p=0.59). Conclusions: Both standard and minimally invasive PCNL have shown good outcomes in the treatment of symptomatic renal stones between 20-40 mm. Although the success rates are similar for both techniques, hospitalisation time, bleeding and transfusion rates are in favor of mPCNL. With the availability of high energy Holmium lasers, even a high stone burden is amenable to mini-PCNL. SOURCE OF Funding: No funding
