Ureteroscopic pneumatic lithotripsy of impacted ureteral calculi.

INTRODUCTION: This work evaluates the results of ureteroscopic treatment of impacted ureteral stones with a pneumatic lithotripter.

MATERIALS AND METHODS: From March 1997 to May 2002, 42 patients with impacted ureteral stones were treated by retrograde ureteroscopic pneumatic lithotripsy. Twenty-eight patients were female and 14 were male. The stone size ranged from 5 to 20 mm. The ureteral sites of the stones were distal in 21, middle in 12 and proximal in 9.

RESULTS: Considering stones with distal location in the ureter, 1 patient had ureteral perforation and developed a stricture in the follow-up (4.7%). As for stones in the middle ureter, 2 perforations and 1 stricture were observed (8.3%) and regarding stones located in the proximal ureter, 5 perforations and 4 strictures occurred (44%). In the mid ureter, 1 ureteral avulsion was verified. In 34 patients without ureteral perforation, only 1 developed a stricture (2.9%). Of 8 patients who had perforation, 6 developed strictures. The overall incidence of stricture following treatment of impacted ureteral calculi was 14.2%.

CONCLUSIONS: Ureteroscopy for impacted ureteral calculi is associated with a higher incidence of ureteral perforation and stricture. Ureteroscopy of proximal ureteral calculi is associated with a high risk of perforation, when compared to mid or distal ureteral calculi. Ureteral perforation at the site of the stone seems to be the primary risk factor for stricture formation in these cases.