Is Retrograde Intrarenal Surgery with Semi-rigid Ureterorenoscope Feasible for Isolated Renal Pelvic Stones?

The main goal in the treatment of renal stones is to attain the greatest stone-free status with minimal morbidity (1). Retrograde intrarenal surgery (RIRS) with holmium laser lithotripsy has become one of the standard treatments for patients with upper urinary tract stones (2,3). RIRS with a flexible ureteroscope (fURS) has been widely adopted and has become an effective, safe option in primary care for upper urinary tract stones smaller than 2 cm (4,5). The use of ureteral access sheaths (UAS) is also recommended during the treatment of kidney stones with fURS (4). On the other hand, it has been reported that the use of UAS may cause serious injuries to the ureter (6).