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. Sling fixation is permanent, but unobstructed voiding was demonstrated in postoperative pressure-flow studies . In contrast compressive slings work by increasing urethral closure pressure (UCP) that can adjusted to patients’ individual postoperative conditions.
To date only very scarce data on urethral closure pressure after male sling implantation exist. The most frequently proposed pressures in the literature range between 30 and 60 cmH2O. However, there is no consensus which pressure is ideal 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 .
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 male sling system has a bilateral anchor fixation within the obturator foramen. The development was based on the experience of transobturator anchoring techniques in female continence surgery. The objective is to facilitate the insertion process of the male sling and to reduce the risk of the procedure by avoiding large needles or trocars. As a fundamental part of the developing process the obturator region was extensively studied and measured in male cadavers. With particular respect to safety and stability the optimal area for anchor insertion was determined. For the utilization in males also a new inserter was developed. 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 of sterile water up to 20 ml, with measurement of RLPP.
Interpretation of results
The newly designed anchor demonstrated easy application and excellent stability. It is suitable for single incision, outside-in, safe and simple fixation of a novel adjustable male sling system. After technical refinements the novel anchored male sling system presented with an easy and reliable insertion process 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.