Causes of Artificial Urinary Sphincter Failure and Strategies for Surgical Revision: Implications of Device Component Survival

Abstract

BackgroundUp to 50% of patients receiving an artificial urinary sphincter (AUS) require surgical revision after initial placement. However, the literature is heterogeneous regarding the leading causes of AUS failure and appropriate surgical management. ObjectiveTo inform a revision approach by tabulating the causes of AUS failure, assessing AUS component survival, and examining the single-component revision efficacy. Design, setting, and participantsWe retrospectively reviewed 168 patients receiving AUS placements carried out by a single surgeon from 2008 to 2016 at a high-volume academic institution. The median follow-up from initial placement was 2.7 yr, with 37.5% experiencing recurrent incontinence. The cuff size ranged from 4.0 to 5.5cm, with median size of 4.5cm. InterventionPatients without infection or erosion underwent systematic device interrogation and revision, starting with the pressure-regulating balloon (PRB) and then, if necessary, the urethral cuff. Device revision involved either PRB-only correction or cuff and PRB revision. Outcome measurements and statistical analysisWe used bootstrapped intervals to estimate the mean time to failure for individual AUS components. Kaplan-Meier estimates were used to compare survival for individual components and for revised devices by revision technique. Results and limitationsPRB malfunction most commonly caused device failure, while cuff or pump malfunction was rare. Among patients undergoing surgical revision, those with PRB-only correction had similar outcomes to those with more extensive device correction (cuff and PRB exchange; p=0.46). This study, while systematic and detailed, is limited by sample size, follow-up length, and its retrospective nature. ConclusionsPRB malfunction most commonly caused AUS failure in our cohort. PRB-only correction may satisfactorily restore AUS function in select patients. Consequently, initial interrogation of the PRB may avoid a second incision and urethral exposure for many patients requiring AUS revision. Patient summaryArtificial urinary sphincters remain prone to failure over time. In many instances, correcting only the pressure-regulating balloon may effectively restore device function, allowing for a less invasive revision.