Tolerance and Effectiveness of Ureteral Stents MEMOKATH ® 051 in Chronic Strictures of the Ureter

Inclusion Criteria: * Age 18-year-old or superior * Chronic stenosis of the ureter treated by placement of a ureteral endoprosthesis for more than six months; * No possibility for surgical or endoscopic treatment of the ureteral stricture * Free Consent, dated and signed by the patient * Affiliated Subject of a regime of French national health and pensions organization. Exclusion Criteria: * Age under 18 year old * Pregnant or nursing Women * Patient having a life expectancy of less than 1 year * Patient having unique kidney * Patient having severe renal insufficiency (creatinin clearance under 30 ml/min) * Possible surgical or endoscopic treatment of ureteral stricture * Repeated urinary tract stones * Urothelial tumor of the bladder * Retro peritoneal fibrosis in the course of evolution * Complications of double J stents requiring more thanks a lot every 6 months * Against anaesthetic indication * Lithiasic inlay probe Double J with obstruction within 6 months * Persons put under maintenance of justice * Persons in inability to understand the sequence of try