Prospective randomised controlled trial to evaluate the efficay of a flexible and navigable suction ureteric access sheath on renal stone clearance compared to conventional access sheath in adult patients of renal stone disease undergoing Retrograde Intrarenal Surgery (RIRS).

Renal calculi are a prevalent urological issue worldwide. Retrograde Intrarenal Surgery (RIRS) has become a primary minimally invasive treatment, especially for upper urinary tract stones.

While effective, conventional RIRS using a standard ureteric access sheath (UAS) has known limitations. Elevated intrarenal pressure during the procedure is a significant concern, increasing the risk of

postoperative fever and sepsis. Furthermore, inefficient removal of stone fragments ("dust") can lead to lower stone-free rates (SFR), potentially requiring secondary procedures. The conventional UAS

can be stiff, posing challenges in tortuous ureters and limiting the evacuation of fragments.

This study aims to address key safety and efficacy challenges in RIRS. A specially designed flexible and navigable suction ureteric access sheath (FANS-UAS) offers potential solutions by reducing

intrarenal pressure, better navigability, and better stone evacuation.