Results: comparatively assessing the outcome of our recent series (perspective series of 25 patients treated from January 2000 to March 2003) and our former series (retrospective series of 63 patients treated from January 1995 to December 1999), we have the following results: the strictures in the latter series seem to be less severe with bilateral stricture rate is 12% versus 20.6%, rate of stricture with ipsilateral renal function impairment is 14.3% versus 28.6%.