title: Ureteral stent duration and the risk of BK polyomavirus viremia or bacteriuria after kidney transplantation.
abstract: OBJECTIVE
  Ureteral stents are used in kidney transplantation (KTX) to decrease post-operative complications, but they are associated with BK polyomavirus viremia (BKV). Our primary outcome was to determine the association between ureteral stent duration and BKV. Secondary outcome measures were the association between bacteriuria and stent duration or use of ureteral stent strings.
  
  
  METHODS
  Between January 2010 and January 2015, 403 patients underwent KTX at the Virginia Mason Medical Center and met inclusion criteria. Stent duration was classified as short (<3 weeks) or long (>3 weeks). Multivariate logistic regression models were created to assess for factors associated with BKV. The covariates in the BKV model were chosen a priori based on stent duration and risk factors previously described in the literature.
  
  
  RESULTS
  Ureteral stents were placed in 304 (75.4%) transplants. Stent strings were left attached in 166 (54.6%) patients. On multivariate analyses, long stent duration was significantly associated with increased risk of BKV compared with no stent (odds ratio [OR] 1.92, P=.044, 95% confidence interval [CI] 1.04-3.74). Short stent duration was not associated with BKV. Sixty-two (15.4%) patients had bacteriuria. Bacteriuria was associated with female gender (OR 2.77, P<.001, 95% CI 1.58-4.95), and there was a dose-dependent effect with stent duration compared with no stent-short duration (OR 2.46, P=.049, 95% CI 1.05-6.49) and long duration (OR 3.58, P=.004, 95% CI 1.58-9.25). Stent strings were not associated with either complication.
  
  
  CONCLUSIONS
  The association between ureteral stents and BKV may be dose dependent.
authors.affiliation: Department of Urology, Madigan Army Medical Center, Tacoma, WA, USA.
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Wingate
authors.affiliation: Department of Urology and Renal Transplantation, Virginia Mason Medical Center, Seattle, WA, USA.
authors.forename: Jared
authors.initials: J
authors.lastname: Brandenberger
authors.affiliation: Department of Nephrology and Renal Transplantation, Virginia Mason Medical Center, Seattle, WA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Weiss
authors.affiliation: Department of Urology and Renal Transplantation, Virginia Mason Medical Center, Seattle, WA, USA.
authors.forename: Lauren G
authors.initials: LG
authors.lastname: Scovel
authors.affiliation: Department of Urology and Renal Transplantation, Virginia Mason Medical Center, Seattle, WA, USA.
authors.forename: Christian S
authors.initials: CS
authors.lastname: Kuhr
mesh_terms: D000328:Adult; D000368:Aged; D001739:BK Virus / Q000302:isolation & purification*; D001437:Bacteriuria / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D027601:Polyomavirus Infections / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D014412:Tumor Virus Infections / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D014513:Ureter; D014546:Urinary Catheterization / Q000009:adverse effects* / Q000295:instrumentation; D014766:Viremia / Q000453:epidemiology* / Q000821:virology
keywords: BK nephropathy; BK viremia; bacteriuria; ureteral stent