Retrograde intrarenal surgery with or without ureteral access sheath: a systematic re-view and meta-analysis of randomized controlled trials.

The ureteral access sheath (UAS) is a medical device that enables repeated entrance into the ureter and collecting system during retrograde intrarenal surgery (RIRS). Its impact on stone-free rates, ureteral injuries, operative time, and postoperative complications remains controversial. Therefore, we performed a systematic review and meta-analysis comparing RIRS with versus without UAS for urolithiasis management.