Supine vs. Prone PCNL for Large Renal Stones: A Randomized Trial in Yemen.

The goal of this clinical trial is to compare the safety, cost-effectiveness, and patient recovery of two different surgical positions for percutaneous nephrolithotomy (PCNL) in adults aged 18 to 70 years who have kidney stones larger than 2 cm. The main questions it aims to answer are: * Does the supine (lying on the back) surgical position result in fewer early postoperative complications than the traditional prone (lying on the stomach) position? * Does the supine position reduce the total surgery time, direct hospital costs, and postoperative pain? Researchers will compare patients assigned to undergo PCNL in the supine position to those assigned to the prone position to see if the supine approach offers a safer, more cost-effective, and more comfortable recovery. Participants will: * Undergo standard PCNL surgery to remove their kidney stones in either the supine or prone position. * Have their pain levels, surgery time, and any early surgical complications monitored during their hospital stay. * Complete brief questionnaires regarding their overall surgical satisfaction and quality of life at 1 month and 3 months after the procedure.