Impact of Adjuvant Radiation on Artificial Urinary Sphincter Durability in Postprostatectomy Patients

Objective: To further understand the implications of adjuvant radiation on artificial urinary sphincter (AUS) durability in postprostatectomy patients. Methods: One hundred fifty-eight postprostatectomy patients, identified by retrospective chart review, underwent AUS placement by 1 surgeon from 2008 to 2016. Time-to-event analysis measured the effect of adjuvant radiation on all-cause failure, and competing-risks regression stratified failure by cause (infection or erosion, urethral atrophy, mechanical failure). Results: Adjuvant radiation independently predicted all-cause failure over time (hazard ratio = 4.32, P <.01) When stratifying failure by cause, we find that adjuvant radiation patients have increased risk of infection or erosion complications (hazard ratio = 4.48, P =.03). However, there was no statistical increase in urethral atrophy or mechanical failure. Lastly, among patients who have urethral comorbidities (bladder neck contracture, prior urethral sling, or urethral stricture), those with radiation history have particularly poor outcomes (22.4% revision-free survival at 3 years). Conclusion: In our series of postprostatectomy patients, adjuvant radiation portends worse AUS device survival over time. Furthermore, this decrease in revision-free survival appears to be concentrated in an increase in infection or erosion complications. Patients with prior urethral injury or manipulation who have also undergone adjuvant radiation should be carefully selected when receiving an AUS as this subset of patients experiences low device survival.