title: Tandem ureteral stents for the decompression of malignant and benign obstructive uropathy.
abstract: OBJECTIVE
  To evaluate the utility of two ipsilateral ureteral stents placed for benign and malignant ureteral obstruction.
  
  
  METHODS
  We performed a retrospective analysis of all cases of tandem ureteral stent (TUS) insertion at our institution from July 2007 through January 2013. Student t, Fisher exact, and log-rank test were used.
  
  
  RESULTS
  TUS insertion or exchange was performed in 187 cases. There were 66 patients (75 renal units) who underwent successful TUS insertion. Malignant ureteral obstruction (MUO) was the cause for obstruction in 39 renal units (34 patients) vs benign ureteral obstruction (BUO) in 36 renal units (32 patients). Four patients with BUO and 15 patients with MUO underwent stent exchanges at a mean 145 and 128 days, respectively. Serum creatinine levels were stable poststent placement (P=0.4). Degree of hydronephrosis improved (paired t test P<0.03) after stent placement for both benign and malignant cohorts. TUS placement was noted to fail (flank pain with worsening hydronephrosis or increasing creatinine level) in five renal units with MUO (12.8%) and none with BUO. Stent failure (either conventional or TUS) suggested worsening survival in those with MUO. Median survival for those with MUO and a history of stent failure (10 of 14 died, 71%) was 66 days compared with 432 days for those without a history of stent failure (8 of 20 died, 40%) (log-rank test P=0.007).
  
  
  CONCLUSIONS
  Our experience with the TUS, the largest to date, demonstrated that they are highly successful in both benign and malignant causes of obstruction, comparing favorably with metallic ureteral stents. Stent failure may be predictive for shorter survival.
authors.affiliation: Smith Institute for Urology, Hofstra North Shore-LIJ Medical School , New Hyde Park, New York.
authors.forename: Sammy E
authors.initials: SE
authors.lastname: Elsamra
authors.forename: Hector
authors.initials: H
authors.lastname: Motato
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
authors.forename: Nikhil
authors.initials: N
authors.lastname: Waingankar
authors.forename: Justin I
authors.initials: JI
authors.lastname: Friedlander
authors.forename: Gary
authors.initials: G
authors.lastname: Weiss
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Smith
authors.forename: Zeph
authors.initials: Z
authors.lastname: Okeke
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D017211:Treatment Failure; D014513:Ureter / Q000601:surgery; D014517:Ureteral Obstruction / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods / Q000401:mortality