Initial Drainage Method and Flexible Ureteroscopy Outcomes in Calculous Anuria

Calculous anuria caused by obstructing upper ureteral stones in a solitary functioning kidney is a urological emergency requiring urgent decompression. Both retrograde JJ ureteral stenting and percutaneous nephrostomy are commonly used emergency drainage methods. However, limited evidence is available regarding whether the initial drainage method affects subsequent definitive flexible ureteroscopy/retrograde intrarenal surgery outcomes. This multicenter prospective randomized controlled trial will compare emergency JJ ureteral stent drainage versus percutaneous nephrostomy drainage in adult patients presenting with calculous anuria due to a single upper ureteral stone in a solitary functioning kidney. After renal functional improvement, clinical stabilization, and appropriate urine culture management, all participants will undergo standardized definitive flexible ureteroscopy/retrograde intrarenal surgery. The study will assess renal functional recovery, first-session surgical success, stone-free rate, operative parameters, complications, and microbiological outcomes.