1690 ROUTINE POSTOPERATIVE IMAGING IS IMPORTANT AFTER URETEROSCOPIC MANAGEMENT OF IMPACTED URETERAL STONES

Abstract

INTRODUCTION AND OBJECTIVES: Improved endoscope and advanced intracorporeal lithotripsy devices have significantly decreased the incidence of complications during ureteroscopy (URS). Despite recent reports suggesting that routine postoperative imaging may not be necessary in all individuals after URS silent obstruction may develop in some, ultimately resulting in renal damage (Weizer AZ, et al. J Urol 168: 46–50, 2002.) We evaluated the incidence and factors associated with postoperative abnormal imaging and assessed the need for routine postoperative imaging after URS. METHODS: We retrospectively reviewed the records of 323 patients who underwent URS for impacted ureteral stones at our institution. Our URS procedure using a small-caliber ureteroscope and a holmium: YAG laser has been reported previously (J. Urol. 171: 89–91, 2004). All of the patients routinely underwent IVP in order to assess for obstruction or delayed excretion at 1 month after URS. Abnormal imaging was defined when postoperative imaging did not show improvement of hydronephrosis. RESULTS: Of the 323 patients 16 (5%) revealed abnormal postoperative imaging without symptoms. All 16 patients underwent secondary ureteroscopy in order to assess and alleviate obstruction. 16 patients with a mean age of 56 years were included. Mean diameter of the initial target stone was 15 mm (range 2–23) with stone location being 11 upper ureter and 5 lower ureter. Mean duration of impaction was 30 months (range 2–72). Second URS revealed obstruction due to ureteral stricture in 13, complete ureteral occlusion in 2 and ureteral tortuosity in 1. Second URS detected a severe ureteral stricture related to laser therapy distal to the successfully treated stone. The obstruction eventually resolved with endoscopic balloon dilation in 14 out of 16 patients. 2 patients ultimately received ureteroureterostomy and 2 were lost to follow-up. Among these 16 patients, initial URS revealed inflammatory ureteral polyps associated with the calculi in 8 and ureteral stricture in 4. Stone location, stone size, operative time, duration of impaction and stone composition were not associated with abnormal post-URS imaging. CONCLUSIONS: Our analysis suggests that silent obstruction remains a potentially significant complication after URS for long-term impacted ureteral stones which are frequently associated with ureteral polyps and strictures. Therefore, we recommend that routine postoperative imaging should be performed after URS to avoid the potential complications of unrecognized ureteral obstruction.