The "Fragile" Urethra as a Predictor of Early Artificial Urinary Sphincter Erosion

Objectives: To identify predictors of early artificial sphincter (AUS) erosion among a cohort of men with erosion, who underwent AUS placement by either university or community-based surgeons.

Methods: The records of all patients with AUS erosions, including men who underwent AUS placement at outside facilities, were retrospectively reviewed. A Cox proportional-hazards model for time to erosion was performed with the predictors being the components of a fragile urethra (history of radiation, prior AUS, prior urethroplasty), androgen deprivation therapy (ADT), trans-corporal (TC), and 3.5 cm cuff, controlling for other risk factors. Kaplan-Meier survival curves and log-rank test compared "fragile" urethras with "not fragile" urethras. All statistical analysis was done using R version 3.5.2.

Results: Of the 156 men included, 36% had undergone AUS placement in the community. Median time to erosion was 16.0 months (1.0-240.0 months), and 122 (78%) met at least one fragility criteria. Radiation (HR 2.36, 95% CI 1.52-3.64) and prior urethroplasty (HR 2.12, 95% CI 1.18-3.80) were independently associated with earlier time to erosion. The Kaplan-Meier estimates demonstrate 1- and 5-year survival rates of 76.5% and 50.0%, respectively, for "non-fragile" and 44.1% and 14.8% for "fragile" urethras (P < .0001).

Conclusion: In a diverse cohort of men with AUS erosion, men with "fragile" urethras eroded sooner. Radiation and prior urethroplasty were independent risk factors for earlier time to erosion, but prior AUS, ADT, TC and 3.5 cm cuff were not.