Failed Insertion of Ureteral Access Sheath During Flexible Ureterorenoscopy

Percutaneous nephrolithotomy (PNL) is the gold standard recommended treatment technique for kidney stones larger than 20 mm. For kidney stones between 10 - 20 mm, both shock wave lithotripsy (SWL) or flexible ureterorenoscopy (f-URS) are recommended as the first choice of treatment and PNL is recommended as the second. In patients who are planned to undergo f-URS, a ureteral access sheath (UAS) is placed in the ureter at the beginning of the operation in order to provide a better image, reduce intra-renal pressure, easier stone fragment retrieval and shorter operative time. In certain cases, such as ureteral stricture, kink or edema, the ureteral access sheath may not be able to successfully inserted into the ureter. At this stage, double-J (JJ) stent can be inserted into the ureter to create passive dilatation, and a second f-URS session can be scheduled a few weeks later. Another option is to perform PNL operation to the patient in the same session. In this randomized prospective study, we aimed to compare these two different surgical approaches in terms of patient comfort and surgical success in patients with kidney stones between 10 - 20 mm in which access sheath insertion was failed in the initial f-URS session.