title: The Impact of Urethral Risk Factors on Transcorporeal Artificial Urinary Sphincter Erosion Rates and Device Survival.
abstract: OBJECTIVE
  We report the impact of urethral risk factors on erosion rates and device survival outcomes after transcorporeal artificial urinary sphincter placement.
  
  
  METHODS
  We performed a retrospective analysis of all transcorporeal artificial urinary sphincters placed at a single institution between January 2000 and May 2014. We assessed patient demographic, comorbid diseases and surgical characteristics for risk factors considered poor for device survival. Risk factors were compared to postoperative complications requiring explantation, including cuff erosion, infection and device revision.
  
  
  RESULTS
  A total of 37 transcorporeal artificial urinary sphincters were placed in 35 men. Placement was performed as a primary procedure in 21 of 37 cases (56.8%) and as salvage in the remainder. In this transcorporeal population there were 7 explantations (18.9%) due to erosion in 4 cases, cuff downsizing in 2 and infection in 1. Median followup from implantation to last followup was 8.5 months (range 0.9 to 63). Median time from artificial urinary sphincter placement to explantation was 17.3 months (range 0.9 to 63) and time specifically to transcorporeal erosion was 7.4 months (range 0.9 to 26). On univariate analysis no parameters were associated with sphincter cuff erosion but a history of an inflatable penile prosthesis was associated with a higher device explantation rate (60% vs 12.5%, p=0.04). No associations were revealed on multivariate logistic analysis. All 4 cuff erosion cases demonstrated greater than 2 urethral risk factors, including prior radiation therapy in all. The probability of cuff erosion in patients with 2 or more urethral risk factors was 1.65 times the probability of erosion in those with 0 or 1 urethral risk factor (95% CI 1.3, 2.2). The proportion of patients free of erosion at 35 months was 100% in those with 0 or 1 urethral risk factor and 64% in those with 2 or more risk factors (log rank test p=0.00). Similarly the proportion of patients free of explantation at 35 months was 100% in those with 0 or 1 urethral risk factor and 52% in those with 2 or more (log rank test p=0.02).
  
  
  CONCLUSIONS
  Transcorporeal artificial urinary sphincter implantation is generally reserved for complex and high risk cases but favorable functional results were demonstrated. However, patients with multiple urethral risk factors face a higher risk of erosion and device loss.
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee. Electronic address: Stephen.mock@vanderbilt.edu.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mock
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Roger R
authors.initials: RR
authors.lastname: Dmochowski
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Brown
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: W Stuart
authors.initials: WS
authors.lastname: Reynolds
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Kaufman
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Milam
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020878:Device Removal; D004867:Equipment Design; D004868:Equipment Failure; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019935:Penile Implantation / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014521:Urethra / Q000293:injuries* / Q000473:pathology*; D014549:Urinary Incontinence / Q000628:therapy*; D016741:Urinary Sphincter, Artificial / Q000009:adverse effects*
keywords: artificial; complications; prostheses and implants; urethra; urinary bladder; urinary sphincter