A Prospective Comparison of Supine and Prone Percutaneous Nephrolithotomy Techniques in Obese Patients

Abstract

To prospectively compare the efficacy and safety of supine versus prone percutaneous nephrolithotomy (PNL) techniques in obese patients. This prospective randomized study included 73 obese patients (BMI > 25) undergoing PNL between June 26, 2024 and June 1, 2025. Patients were assigned to supine (n = 36) or prone (n = 37) groups. Demographic data, stone characteristics, operative parameters, and complications were analyzed. Statistical analyses were performed using SPSS v26, with significance set at p < 0.05. No significant differences were found between the groups in terms of age, BMI, stone size, or hospital stay (p > 0.05). The supine group demonstrated significantly shorter operative time (79.9 +/- 17.9 vs. 97.7 +/- 16.2 min, p < 0.001) and access tract length (4.8 +/- 0.7 vs. 6.2 +/- 0.8 cm, p < 0.001). Stone-free rates, DJ stent placement, transfusion requirements, and complication rates (Clavien-Dindo classification) were comparable between the groups (p > 0.05). Both supine and prone PNL are safe and effective options for obese patients with renal stones >= 2 cm. However, supine PNL provides advantages including shorter operative time, reduced access tract length, and avoidance of patient repositioning, making it a preferable approach for this patient population.