Flexible Ureteroscopy for Treatment of Upper Urinary Tract Calculus.

The aim of this article is to illustrate a step-by-step guide to flexible ureteroscopy (URS) for treatment of upper urinary tract calculus. Preoperative evaluation of the patient with focus on comorbidities is paramount for the type of stone procedure to be performed. In this article, the steps of operating room setup, patient positioning, gaining access to the upper urinary tract, flexible URS, laser lithotripsy, basket extraction of stone fragments, and placement of a ureteral stent are described. The importance of clearance of the ureter before flexible URS in the case of pre-existing ureteral stone is also described.