Patterns and timing of artificial urinary sphincter failure

Abstract

Purpose: To assess population-based trends in artificial urinary sphincter (AUS) placement after prostatectomy and determine the effect of timing on device survival and complications.

Methods: We identified patients who underwent prostatectomy and AUS placement in SEER-Medicare from 2002 to 2011. We analyzed factors affecting the time of reoperation from AUS implantation and prostatectomy using multivariable Cox proportional hazard models.

Results: In total, 841 men underwent AUS placement at a median 23 months after prostatectomy. Patients who underwent reoperation (28.5%) had higher clinical stage, more likely underwent open prostatectomy, or had prior sling placement (p < 0.03). There were no differences in rates of diabetes, smoking status, prior radiation therapy, or Charlson Comorbidity Index between those requiring reoperation vs. not (all p > 0.15). Patients with AUS placement > 15 months after prostatectomy (75%) initially experienced less need for operative reinterventions. Patients with later AUS placement were significantly more likely to have received radiation therapy [22.9 vs. 3.8% (p < 0.01)]. Nonetheless, late implantation was confirmed to be protective on multivariate analysis during the first 5 years after AUS placement [HR 0.79 (95% CI 0.67-0.92); p < 0.01]. Factors independently associated with a shorter interval time until reoperation included history of radiation [HR 1.93 (95% CI 1.33-2.80); p < 0.01] and history of prior sling [HR 1.70 (95% CI 1.08-2.68); p = 0.02]. Even for patients who underwent radiation therapy, delayed AUS implantation reduced reoperative risk.

Conclusions: Late AUS implantation in the Medicare population is associated with prolonged device survival initially, while radiation and prior sling surgery predict for earlier reoperation. Patients with delayed AUS implantation experience less immediate complications. Further work is required to identify patient-specific factors which may explain variability in timing for AUS.

Keywords: Artificial urinary sphincter (AUS); Explantation; Post-prostatectomy incontinence; Radiation; Revision; Timing.