Percutaneous Nephrolithotomy in Supine versus Prone Position in Tertiary Hospital in Mysore: A Prospective Cohort Study

Introduction: Percutaneous Nephrolithotomy (PCNL) is a procedure of choice for large renal calculi. It is a common urological procedure. PCNL can be performed in various positions. Aim: To determine the surgical outcomes in patients undergoing PCNL in supine and prone positions. Materials and Methods: A cohort study was conducted on patients with renal and upper ureteral stones who underwent PCNL in either prone or supine position between August 2019 to August 2020 at Urology Department, JSS Hospital, Mysuru. Supine PCNL was done in the flank Free Oblique Supine Modified Lithotomy (FOSML) position. All the procedures were performed under fluoroscopy guidance. Surgical outcomes including operative time, length of hospital stay, Stone Free Rate (SFR), radiation dose, and postoperative complications were evaluated. The collected data was tabulated and frequency (n) and percentage (%) analysis was performed. The Chi-square test was used to find the level of significance. Results: A total of 70 patients were included in the study and out of which 35 patients were in the supine (46.37±14.73 years, 28 males and 7 females) and 35 patients (47.54±12.45 years, 23 males and 12 females) were in the prone PCNL groups. Statistically significant difference was observed in the mean operating time in the supine and prone PCNL groups (81.43 vs 127.71 minutes; p-value=0.001), with a higher stone-free rate (94.29% vs 91.43%; p-value=0.643) observed in the supine PCNL group. One patient in supine group had postoperative sepsis and one patient in prone group had bleeding requiring transfusion. The Visual Analog Scale (VAS) score in supine PCNL was (5.08±0.32) less than in prone group (8.03±0.40) (p-value <0.001). Conclusion: PCNL in the supine position compared with the prone position demonstrates significantly lower operative time with similar SFR and lower VAS score.