The female continence mechanism measured by high resolution manometry: Urethral bulking versus midurethral sling

Abstract

Aims Traditional technology to characterize urethral pressure changes during dynamic conditions is limited by slow response times or artifact-inducing withdrawal maneuvers. The 8F high-resolution manometry (HRM) catheter (ManoScan™ ESO, Covidien) has advantages of fast response times and the ability to measure urethral pressures along the urethral length without withdrawal. Our objective was to determine static and dynamic maximum urethral closure pressures (MUCPs) and resting functional urethral length (FUL) in women using HRM before and after transurethral bulking and compare results to other women who underwent midurethral sling (MUS). Methods We recorded rest, cough, and strain MUCPs and FUL in 24 women before and after transurethral bulking with polydimethylsiloxane (Macroplastique®) using the HRM catheter and compared these changes to HRM values from 26 women who had the same measures before and after MUS. Results At rest, MUCPs increased minimally after both urethral bulking and MUS (3 vs 0.4 cm H2O respectively, P = 0.4). Under dynamic conditions there were statistically insignificant small increases in MUCP and these increases were markedly less than after MUS (cough: 1.5 vs 63.8 cm H2O, P < 0.001 and strain: 11.5 vs 57.7 cm H2O, P < 0.001). FUL increased by 0.5 cm after transurethral bulking (P = 0.003), and decreased by 0.25 cm after MUS placement (P = 0.012). Conclusions The mechanism of continence after urethral bulking differs from MUS. While MUS increases dynamic MUCP, bulking may rely on increasing the length of the continence zone.

Urethral function and failure: A review of current knowledge of urethral closure mechanisms, how they vary, and how they are affected by life events

“…Also, the impact of urethral support surgery and bulking injections on the urethral function has been reported. No statistically significant change was found in rest MUCP after retropubic and transobturator mid‐urethral slings and bulking agents 7–9 . If, as we show in this review, urethral failure is the dominant causal factor for SUI and operations do not change this, some incontinence would be expected postoperatively.…”

“…No statistically significant change was found in rest MUCP after retropubic and transobturator midurethral slings and bulking agents. [7][8][9] If, as we show in this review, urethral failure is the dominant causal factor for SUI and operations do not change this, some incontinence would be expected postoperatively. This suggests that, in the absence of interventions targeting low urethral closure pressure, surgical results from support operations are bound to remain imperfect.…”

Up-to-Date Procedures in Female Stress Urinary Incontinence Surgery: A Concise Review on Bulking Agents Procedures

“…Further, 33 articles were reviewed and excluded because they did not satisfy the eligibility criteria. Nineteen studies concerning the efficacy and safety of UBAs for the treatment of SUI were included in this review: two of them were RCTs [9,10], while the other 17 studies [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] presented a prospective non-controlled or non-randomized design.…”

High resolution manometry catheter, test retest reliability and the working mechanism of urethral bulking?

“…It is important to understand the mechanism of urethral bulking in order to optimize the surgical technique and select the right patients. We were, therefore, attracted by the paper by Wasenda et al…”

“…It is important to understand the mechanism of urethral bulking in order to optimize the surgical technique and select the right patients. We were, therefore, attracted by the paper by Wasenda et al 1 Wasenda et al's paper is the most recent in a series of studies with remarkable results based on the high-resolution manometry (HRM) catheter. We would like to comment on the following: 1) Test-retest reliability: In a previous study 2 the group has showed that the limit of agreement for Maximum Urethral Closure Pressure (MUCP) during dynamic conditions is ±40 cmH 2 O.…”