title: Ureteral metal stents: 10-year experience with malignant ureteral obstruction treatment.
abstract: OBJECTIVE
  Ureteral patency in malignant ureteral obstruction cases is a therapeutic challenge. We report our long-term experience with palliative treatment for extrinsic malignant ureteral obstruction with percutaneous placement of metal mesh stents.
  
  
  METHODS
  From January 1996 to December 2005, 90 patients with a mean age of 59 years (range 35 to 80) with ureteral obstruction due to extrinsic ureteral compression and/or encasement by primary or metastatic tumors, or retroperitoneal lymphadenopathy underwent implantation of self-expandable metal mesh stents. A total of 119 ureters were managed. Followup included urinalysis, blood biochemistry tests and transabdominal ultrasound or intravenous urography.
  
  
  RESULTS
  The technical success rate of percutaneous antegrade insertion of ureteral self-expandable metal mesh stents was 100%. Renal biochemistry normalized and hydronephrosis gradually resolved 1 to 2 weeks after stent insertion. Median followup was 15 months (range 8 to 38). Hyperplastic reaction and/or encrustation, or tumor ingrowth developed in 45 stents. Secondary intervention, such as repeat balloon dilation and coaxial stenting, was done to improve patency. Migration was observed in 13 metal stents. The primary and secondary patency rates during followup were 51.2% and 62.1%, respectively. A double pigtail or external-internal stent was inserted in 45 cases in which secondary interventions did not ensure patency.
  
  
  CONCLUSIONS
  Internal drainage of extrinsic malignant ureteral obstruction with metal mesh stents provides long-term decompression of the upper urinary tract in select cases. Certain problems limit the application of metal mesh stents in the ureter. Further studies are warranted to identify independent predictors of ureteral patency after the application of metal stents for malignant obstruction.
authors.affiliation: Department of Urology, University of Patras, Patras, Greece. liatsikos@yahoo.com
authors.forename: Evangelos N
authors.initials: EN
authors.lastname: Liatsikos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Karnabatidis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Katsanos
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kallidonis
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Katsakiori
authors.forename: George C
authors.initials: GC
authors.lastname: Kagadis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Christeas
authors.forename: Zafiria
authors.initials: Z
authors.lastname: Papathanassiou
authors.forename: Petros
authors.initials: P
authors.lastname: Perimenis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Siablis
mesh_terms: D000008:Abdominal Neoplasms / Q000150:complications; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008875:Middle Aged; D011474:Prosthesis Design; D015607:Stents; D013997:Time Factors; D014513:Ureter / Q000601:surgery*; D014517:Ureteral Obstruction / Q000209:etiology* / Q000601:surgery*