Semirigid ureteroscopy prior retrograde intrarenal surgery (RIRS) helps to select the right ureteral access sheath

To evaluate ureteral compliance through semirigid ureteroscopy (sURS) in order to select the proper ureteral access sheath (UAS) size for retrograde intrarenal surgery (RIRS).

In a prospective study, 100 consecutive patients selected for elective sURS or RIRS were recruited. Each patient, initially underwent 9.5 Fr sURS with a safety guidewire 3Fr, in order to estimate ureteral compliance. If the ureter was compliant, a gently passage of a 12/14Fr UAS was attempted. If the ureter was not deemed compliant, passage of either a smaller UAS or a smaller semirigid 7Fr or a flexible 7.5Fr or a digital 8.5Fr scope with and without safety guidewire, was attempted. Age, gender, disease location, prestenting, previous RIRS and/or stone elimination, hydronephrosis, ureteral strictures, unsuccessful procedures, and complications, were analyzed as possible correlated factors of ureteral compliance.

In 77 patients the ureter was deemed compliant ≥ 14Fr. Of the preoperative factors that were examined, stent placement before RIRS (P < 0.002), previous RIRS (P = 0.000) and previous stone elimination (P = 0.004), correlated with ureter ≥ 14Fr. Ureteral lithiasis (P < 0.001), ureteral strictures (P < 0.05), unsuccessful procedures (P < 0.005) and complications (P = 0.01) correlated with ureter < 14Fr. The complication rate was 10% (10 patients) with ureteral injuries grade I in 9 patients and grade III in 1 patient according to the endoscopic grading system. Age, gender, hydronephrosis and urothelial carcinoma (UC) had no influence.

sURS performed before RIRS allows selection of the right ureteral access sheath (UAS) and avoidance of major complications. Pre-stenting, previous RIRS and stone elimination history are all factors correlating with a compliant ureter.