title: Early Application of Permanent Metallic Mesh Stent in Substitution for Temporary Polymeric Ureteral Stent Reduces Unnecessary Ureteral Procedures in Patients With Malignant Ureteral Obstruction.
abstract: OBJECTIVE
  To identify risk factors for metal stent failure in patients who received polymeric double J (PDJ) ureteral stents for malignant ureteral obstructions (MUOs) and review our clinical experiences using a ureteral metallic stent.
  
  
  METHODS
  Patients who underwent metallic stent placement to replace a double J ureteral stent for nonurological MUO between January 2011 and February 2014 were included. The collected data included gender, age, laterality, cause of obstruction, PDJ ureteral stenting duration, immediate success of the metal stent, and additional procedures to relieve obstruction after metal stenting (eg, additional metal stenting or percutaneous nephrostomy (PCN) indwelling catheter placement). Cox regression tests were used for the statistical analyses.
  
  
  RESULTS
  In this analysis 40 ureteral units were included. There was no initial technical failure. However, 9 (22.5%) units required additional procedures due to de novo ureteral obstruction, including additional indwelling metal stents (7.5%), additional PDJ stenting (10%), or indwelling percutaneous nephrostomy (5%). Univariate and multivariate analyses revealed that the duration of previous PDJ ureteral stenting was an independent prognostic factor for predicting ureteral metal stent failure (hazard ratio = 1.063, 95% confidence interval = 1.004-1.125; P = .037).
  
  
  CONCLUSIONS
  Long-term indwelling of a PDJ ureteral stent increases the risk of additional management for de novo ureteral stricture after ureteral metal stent replacement for nonurological MUO. Our data suggest that careful patient selection and counseling for those at high risk are needed when metal stent replacement is considered for patients with long-term PDJ ureteral stents for MUO.
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ki Hong
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Urology, Gangnam Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kang Su
authors.initials: KS
authors.lastname: Cho
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Won Sik
authors.initials: WS
authors.lastname: Ham
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea. Electronic address: khan@yuhs.ac.
authors.forename: Kyung Seok
authors.initials: KS
authors.lastname: Han
mesh_terms: D000368:Aged; D004067:Digestive System Neoplasms / Q000473:pathology; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005833:Genital Neoplasms, Female / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D000069322:Self Expandable Metallic Stents; D014517:Ureteral Obstruction / Q000209:etiology* / Q000601:surgery*