title: Management of encrusted ureteral stents impacted in upper tract.
abstract: OBJECTIVE
  To present our series of patients with ureteral stent encrustation and give indwelling times and management. Encrustation is one of the most serious complications of ureteral stents.
  
  
  METHODS
  A retrospective review was undertaken of all encrusted stents during a 4-year period. The inclusion criterion was a stent that required some form of intervention above the ureteral orifice to remove it. Combinations of extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and open surgery were used to achieve stent removal.
  
  
  RESULTS
  Forty-nine impacted encrusted stents were treated in 41 patients. Of these, 75.5% had become encrusted within 6 months and 42.8% within 4 months. The mean indwelling time was 5.6 months. Forty-seven stents were removed by endourologic techniques, with 4 requiring extracorporeal shock wave lithotripsy alone, 28 ureteroscopy, and 10 a combination of both. Five patients underwent successful percutaneous nephrolithotomy. One patient underwent open surgery, and in one removal failed. The mean number of procedures per patient was 1.94.
  
  
  CONCLUSIONS
  Stent encrustation can pose a serious challenge to the endourologist, and indwelling times should be minimized to avoid problems. Patients often require multiple treatments and a combination of extracorporeal shock wave lithotripsy and ureteroscopy offers highly successful outcomes and often avoids the need for more invasive techniques.
authors.affiliation: Department of Urology, Guy's and St. Thomas' Hospital, London, United Kingdom.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Bultitude
authors.forename: Richard C
authors.initials: RC
authors.lastname: Tiptaft
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Glass
authors.forename: Prokar
authors.initials: P
authors.lastname: Dasgupta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D020878:Device Removal / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D053685:Laser Therapy; D008096:Lithotripsy / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000209:etiology / Q000601:surgery / Q000628:therapy*; D014517:Ureteral Obstruction / Q000209:etiology / Q000601:surgery / Q000628:therapy*; D018666:Ureteroscopy / Q000706:statistics & numerical data