Effective Adjustment of Retrograde Leak Point Pressure by a Novel Anchored Male Continence System

Anding R1, Kirschner-Hermanns R1

Research Type

Clinical

Abstract Category

Male Lower Urinary Tract Symptoms (LUTS) / Voiding Dysfunction

Abstract 675
Non Discussion Abstracts
Scientific Non Discussion Abstract Session 36
Stress Urinary Incontinence Male New Devices Pre-Clinical testing Surgery
1. University Hospital Bonn
Links

Abstract

Hypothesis / aims of study
In the management of male stress urinary incontinence a distinction is made between functional and compressive sling implants. An example of a functional sling is the AdVance™ sling (AMS Men’s Health/Boston Scientific, MA, USA) that was introduced in 2006. An unobstructed voiding could be demonstrated in postoperative pressure/flow studies [1]. In contrast compressive slings work by increasing urethral closure pressure (UCP) that can be fixed or variable. In particular adjustable sling systems are designed to adapt to patients’ individual conditions with variable compression of the urethra. 
To date only very scarce data on urethral closure pressure after male sling implantation exist. Furthermore there is no consensus which pressure should be aimed for to restore continence in males. Some authors declare a pressure of 50 cmH2O as a reasonable threshold, whereby maximal urethral closure pressure (MUCP) and retrograde leak point pressure (RLPP) were equally applicable parameters [2]. The most frequently proposed pressures in the literature range between 30 and 60 cmH2O.
We introduce a novel anchored male continence system that facilitates the insertion process by avoiding large trocars. Effectivity was measured as retrograde leak point pressure in fresh male cadavers.
Study design, materials and methods
The newly developed sling system has a bilateral anchor fixation within the obturator foramen. Pressure adaptation on the bulbar urethra is achieved with a water filled cushion that is integrated in the central part of the sling. The filling process is conducted via a subcutaneous port. We performed simulated operations in seven fresh male cadavers and measured the retrograde leak point pressure with a central venous pressure manometer. In each cadaver four series of measurements were conducted after sling insertion, sling tensioning, sling fixation, and wound closure. The cushion was filled stepwise with 1 ml sterile water up to 20 ml, RLPP was measured in cmH2O.
Results
The implantation process of the novel sling systems succeeded frequently quick, simple, safe, and easily reproducible (Fig1). In the initial series the desired pressure transmission on the urethra could not yet be achieved due to instability of the central cushion. After technical improvements with better stabilization of the central cushion steadily increasing pressures (RLPP) were measured with gradient filling of the cushion. Retrograde leak point pressures above 30 cmH2O were achieved with filling volumes of the cushion under 10 ml. With a filling volume between 12 and 15 ml the threshold of 50 cmH2O was frequently reached (Fig2). In some series RLPP even increased above 100 cmH2O.
Interpretation of results
After technical refinements the novel anchored male sling system presented with an easy and reliable insertion process. The anchor fixation worked reliably to keep the sling and the central cushion in place. 
With the novel anchored male sling system the retrograde leak point pressure can be effectively adjusted as a function of the filling volume of the central cushion. With regard to the literature the desired pressures between 30 and 60 cmH2O could be well achieved with low filling volumes. The relation of the filling volume of the device, urethral closure pressure, and continence status has to be determined in future clinical studies.
Concluding message
The novel anchored male adjustable sling system can effectively increase urethral closure pressure as measured as retrograde leak point pressure in fresh male cadavers. With the simple, minimally invasive, and reliable insertion process the device shows a potential to improve male continence surgery.
Figure 1
Figure 2
References
  1. Soljanik I, Becker AJ, Stief CG, Gozzi C, Bauer RM. Urodynamic parameters after retrourethral transobturator male sling and their influence on outcome. Urology. 2011 Sep;78(3):708-712
  2. Comiter CV, Sullivan MP, Yalla SV. Correlation among maximal urethral closure pressure, retrograde leak point pressure, and abdominal leak point pressure in men with postprostatectomy stress incontinence. Urology. 2003 Jul;62(1):75-78.
Disclosures
Funding Grant of the German Federal Ministry for Economic Affairs and Energy (BMWi) through the 'Central Innovation Program medium-sized businesses (ZIM)' Clinical Trial No Subjects Human Ethics not Req'd No living individuals were involved in the study. During lifetime, all subjects donated their body to the Anatomy institute after death and gave written consent to medical research activities on their cadavers. This was confirmed and in agreement with the local ethics committee. Helsinki Yes Informed Consent Yes