title: Predicting factors for stent failure-free survival in patients with a malignant ureteral obstruction managed with ureteral stents.
abstract: OBJECTIVE
  To determine predictive factors for stent failure-free survival in patients treated with a retrograde ureteral stent for a malignant ureteral obstruction.
  
  
  METHODS
  We retrospectively reviewed 71 patients who underwent insertion of a cystoscopic ureteral stent due to a malignant ureteral obstruction between May 2004 and June 2011. Performance status, type of cancer, hydronephrosis grade, location of the obstruction, presence of bladder invasion, C-reactive protein (CRP), serum albumin, and inflammation-based prognostic score (Glasgow prognostic score, GPS) were assessed using a Cox proportional regression hazard model as predicting factors for stent failure.
  
  
  RESULTS
  A univariate analysis indicted that hypoalbuminemia (<3.5 g/dL; hazard ratio [HR], 2.43; 95% confidence interval [CI], 1.21 to 4.86; p=0.012), elevated CRP (≥1 mg/dL; HR, 4.79; 95% CI, 2.0 to 11.1; p=0.001), and presence of a distal ureter obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.021) were associated with stent failure-free survival. A multivariate analysis revealed that the presence of a mid and lower ureteral obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.007), GPS ≥1 (HR, 7.22; 95% CI, 2.89 to 18.0; p=0.001), and elevated serum creatinine before ureteral stent placement (>1.2 mg/dL; HR, 2.16; 95% CI, 1.02 to 4.57; p=0.044) were associated with stent failure-free survival.
  
  
  CONCLUSIONS
  A mid or lower ureteral obstruction, GPS ≥1, and serum creatinine before ureteral stent insertion >1.2 mg/dL were unfavorable predictors of stent failure-free survival. These factors may help urologists predict survival time.
authors.affiliation: Department of Urology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Seong Hyeon
authors.initials: SH
authors.lastname: Yu
authors.forename: Je Guk
authors.initials: JG
authors.lastname: Ryu
authors.forename: Se Heon
authors.initials: SH
authors.lastname: Jeong
authors.forename: Eu Chang
authors.initials: EC
authors.lastname: Hwang
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Jang
authors.forename: In Sang
authors.initials: IS
authors.lastname: Hwang
authors.forename: Ho Song
authors.initials: HS
authors.lastname: Yu
authors.forename: Sun-Ouck
authors.initials: SO
authors.lastname: Kim
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Jung
authors.forename: Taek Won
authors.initials: TW
authors.lastname: Kang
authors.forename: Dong Deuk
authors.initials: DD
authors.lastname: Kwon
authors.forename: Kwangsung
authors.initials: K
authors.lastname: Park
authors.forename: Jun Eul
authors.initials: JE
authors.lastname: Hwang
authors.forename: Geun Soo
authors.initials: GS
authors.lastname: Kim
keywords: Neoplasm metastasis; Stents; Ureteral obstruction