In an attempt to ameliorate the outcome of treatment, we make a comparison between our recent selective series of 25 patients (since year 2000) and our former series (all patients treated from January 1995 to December 1999), we receive the following results: the strictures 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%.