title: Metallic ureteral stents in malignant ureteral obstruction: clinical factors predicting stent failure.
abstract: OBJECTIVE
  To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure.
  
  
  METHODS
  Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure.
  
  
  RESULTS
  A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration.
  
  
  CONCLUSIONS
  Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.
authors.affiliation: 1 Department of Urology, National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei, Taiwan .
authors.forename: Po-Ming
authors.initials: PM
authors.lastname: Chow
authors.forename: Jui-Shan
authors.initials: JS
authors.lastname: Hsu
authors.forename: Chao-Yuan
authors.initials: CY
authors.lastname: Huang
authors.forename: Shuo-Meng
authors.initials: SM
authors.lastname: Wang
authors.forename: Yuan-Ju
authors.initials: YJ
authors.lastname: Lee
authors.forename: Kuo-How
authors.initials: KH
authors.lastname: Huang
authors.forename: Hong-Jheng
authors.initials: HJ
authors.lastname: Yu
authors.forename: Yeong-Shiau
authors.initials: YS
authors.lastname: Pu
authors.forename: Po-Chin
authors.initials: PC
authors.lastname: Liang
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000150:complications*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D014517:Ureteral Obstruction / Q000097:blood / Q000209:etiology / Q000601:surgery*
chemical_list: D015415:Biomarkers; D003404:Creatinine