MP23-04 DOES PERI-CALCULUS URETERAL THICKNESS (P-CUT) ON CT PREDICT STONE IMPACTION AT TIME OF SURGERY? A PROSPECTIVE ANALYSIS

INTRODUCTION AND OBJECTIVES:Impacted ureteral stones are associated with edema and hypertrophy of the ureteral mucosa, which often makes endoscopic ureteral stone surgery more challenging. If an easily measured parameter on preoperative CT scan could predict significant ureteral stone impaction, a urologist would be better prepared for patient counseling of associated risks and outcomes of surgery.METHODS:After IRB approval, we prospectively collected intraoperative data on 34 patients who had a preoperative CT scan and underwent ureteroscopy (URS) for ureteral stones. Surgeons were blinded to preoperative CT parameters except for stone size, location, and degree of hydronephrosis. Stones were considered impacted at surgery if contrast had difficulty passing proximal to the stone, or if a guidewire could not pass, and the stone was visually impacted >5 on a Likert scale. We correlated intra-operative findings to preoperative CT measurements of ureteral thickness on a coronal series directly above, around ...