Proof of concept: Exposing the myth of urethral atrophy after artificial urinary sphincter via assessment of circumferential recovery after capsulotomy and intraoperative pressure profiling of the pressure regulating balloon

Abstract

PurposeRate of continence after artificial urinary sphincter (AUS) placement appears to decline with time. After appropriate workup to exclude inadvertent device deactivation, development of urge or overflow incontinence, and fluid loss, many assume recurrent stress urinary incontinence (rSUI) to be secondary to nonmechanical failure, asserting urethral atrophy as the etiology. We aimed to characterize the extent of circumferential urethral recovery following capsulotomy and that of pressure regulating balloon (PRB) material fatigue in men undergoing AUS revision for rSUI.Materials and MethodsRetrospective review of a single surgeon database was performed. Cases of AUS removal/replacement for rSUI involving ventral subcuff capsulotomy and intraoperative PRB pressure profile assessments were identified.ResultsThe described operative approach involving capsulotomy was applied in 7 patients from November 2015 to September 2017. Mean patient age was 75 years. Mean time between AUS placement and revision was 103 months. Urethral circumference increased in all patients after capsulotomy (mean increase 1.1 cm; range 0.5–2.5 cm). Cuff size increased, remained the same, and decreased in 2, 3, and 2 patients, respectively. Six of 7 patients underwent PRB interrogation. Four of these 6 PRBs (66.7%) demonstrated pressures in a category below the reported range of the original manufacturer rating.ConclusionsDespite visual appearance to suggest urethral atrophy, subcuff capsulotomy results in increased urethral circumference in all patients. Furthermore, intraoperative PRB profiling demonstrates material fatigue. Future multicenter efforts are warranted to determine if capsulotomy, with or without PRB replacement, may simplify surgical management of rSUI with reductions in cost and/or morbidity.

Diagnosis, management, and outcome of urethral obstruction secondary to the capsule associated with the artificial urethral sphincter device

“…In humans with AUS devices, a fibrous capsule consistently forms not only around the AUS device, but also around the urethra that is within the region of the AUS cuff, even in patients without any clinical signs 10 . It was initially thought that urethral atrophy secondary to cuff placement around the urethra was responsible for humans with AUS developing stranguria, but it has now been determined that affected patients had compression of the urethra from the capsule associated with the AUS device 10,11 . In these studies, after capsulotomy or capsulectomy, the urethra returned to its normal shape from the “hour glass” appearance caused by capsular contracture 10,11 …”

“…10 It was initially thought that urethral atrophy secondary to cuff placement around the urethra was responsible for humans with AUS developing stranguria, but it has now been determined that affected patients had compression of the urethra from the capsule associated with the AUS device. 10,11 In these studies, after capsulotomy or capsulectomy, the urethra returned to its T A B L E 1 Bacteria cultured from AUS device and associated capsule, fluid associated with the AUS device and capsule or both…”

Reply by Authors

“…Capsule incision is increasingly cited as a potential treatment for recurrent incontinence. Dr Terlecki’s retrospective analysis of 7 patients published in Investigative and Clinical Urology as a proof-of-concept article is often cited 1 ; however, we feel that this paper demonstrates the multifaceted nature of recurrent incontinence more so than the efficacy of capsulotomy alone. Notably in their study, 6 of the 7 patients had balloon pressures less than 61 cm H 2 O at the time of revision.…”

“…Additionally, they performed a full component replacement in all with replacement cuffs ranging in sizes from smaller to larger than the original and only a short mention of number of subsequent pad usage for clinical follow-up. 1 While the argument is made that the urethra diameter increased more than a centimeter after incision, we do not think this relates at all to clinical outcomes. Size of the urethra in primary placement cases has never been thought to relate to better or worse outcomes for continence in the literature, but rather cuff downsizing and appropriate cuff sizing has proven to be an effective management of recurrent incontinence, with appropriate sizing reducing need for repeated revision.…”

Editorial Comment

“…In artificial urinary sphincter (AUS) revision cases such as those described in this manuscript (ie, non-eroded, functional devices, with worsening objective and subjective incontinence), 1 I have implemented the technique of capsule incision at the time of in situ AUS replacement and will now routinely incise the capsule bilaterally, and laterally, to allow for “expansion” of the sponge prior to replacement. 2 The pre-/post-incision measurement differences are generally 1 cm, and I have been amazed at how much the urethra appears to “recover” after these incisions. Though “wasting” is initially present, once the capsule is incised, it is clear that the urethra is not atrophic, as has been shown by others.…”