MP78-18 PRESSURE REGULATING BALLOONS LOSE PRESSURE AND ELASTICITY IN A TIME-DEPENDENT MANNER

Abstract

You have accessJournal of UrologyCME1 Apr 2023MP78-18 PRESSURE REGULATING BALLOONS LOSE PRESSURE AND ELASTICITY IN A TIME-DEPENDENT MANNER Kevin Krughoff, Jordan Foreman, and Andrew Peterson Kevin KrughoffKevin Krughoff More articles by this author , Jordan ForemanJordan Foreman More articles by this author , and Andrew PetersonAndrew Peterson More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003355.18AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The Artificial Urinary Sphincter (AUS) relies on an elastic pressure regulating balloon (PRB) to generate urethral closure pressure. Reports suggest that material fatigue may be a common driver of device replacement. Our objective was to characterize the nature of material fatigue. METHODS: We compared the pressure and elasticity characteristics of new and used 61-70cmH20 PRBs extracted during AUS removal or replacement surgeries. Pressure-volume curves were generated using commercially available urodynamics equipment in a standardized fashion. PRB pressures were measured at 23cc (standard fill volume) and 30cc (overfill volume). Elastance was calculated by the slope of the tangent line at the inflection point of the pressure-volume curve. Tests were repeated 5 times per PRB and intraclass correlations were used to gauge test-retest reliability. Regression models were used for continuous variables based on data distribution. RESULTS: PRBs from 15 consecutive AUS removal or revision cases were tested. Indications included fluid leak at the cuff (7), sub-cuff atrophy (4) and erosion (4). Time to removal ranged from 0.5 to 16.5 years (mean 7.8±4.7). The mean pressure of all extracted PRBs was 62.2cmH2O (± 4.8) with 7 (46.7%) PRBs below the standard operating range (56-60cmH2O). Each year of PRB use was associated with 0.63cmH20 pressure loss on linear regression (p<0.01 CI -1.04 to -0.22). Pressures were no different whether removed for atrophy (62.8±4.4), cuff fluid leak (60.3±3.1) or erosion (65.0±7.0) (p=0.13). Loss of elastance was non-linear, declining at a rate of approximately 5% per year on Poisson regression (p<0.01, CI -0.07 to -0.03). When compared to pressures generated at standard fill volumes, PRBs less than 1 year old lost pressure when overfilled to 30cc whereas older PRBs gained pressure when overfilled in linear fashion (+1.19cmH20 per year, p<0.01, CI 0.96 to 1.422). The oldest PRB (16 years) exhibited the lowest elasticity and greatest increase in pressure when overfilled (+21cmH2O), while the youngest PRB (0.02 years) exhibited the highest elasticity and lost pressure (-3cmH2O) when overfilled. CONCLUSIONS: In this small series of PRBs tested ex-vivo for pressure-volume characteristics, increasing PRB age was associated with decreased pressure, decreased elasticity and increased pressure when overfilled. These findings have implications for single-component replacement in older devices. The relationship between loss of elasticity and recurrent stress incontinence deserves further investigation. Source of Funding: Boston Scientific Fellowship Grant © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1139 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kevin Krughoff More articles by this author Jordan Foreman More articles by this author Andrew Peterson More articles by this author Expand All Advertisement PDF downloadLoading ...