Hemodynamic Effects of Surgical Position in Prone vs. Supine Percutaneous Nephrolithotomy

Patients in this arm will undergo percutaneous nephrolithotomy (PNL) in the prone position. The procedure begins with ureteral catheter placement in lithotomy position, followed by prone positioning for renal access under C-arm fluoroscopic guidance. Stone fragmentation will be performed using pneumatic or ultrasonic lithotripters, and nephrostomy placement will be completed according to standard protocol.

Patients in this arm will undergo percutaneous nephrolithotomy (PNL) in the Galdakao-modified Valdivia supine position. Following general anesthesia, the ipsilateral side will be elevated 20-30°, with the ipsilateral leg extended and the contralateral leg abducted. Ureteral catheter placement will be followed by renal access under C-arm fluoroscopy. Stone fragmentation and removal will be performed using the same standardized lithotripsy and irrigation protocols as in the prone group.