Login to Access Video or Poster Abstract: MP46-14
Sources of Funding: None

Introduction

The artificial urinary sphincter (AUS) AMS 800 has proven to be very effective in treatment of stress urinary incontinence. However, surgeon practice patterns vary when the device does not provide the desired degree of dryness. A common approach utilized is to add additional fluid to the pressure regulating balloon (PRB). The goal of this study was to evaluate changes in pressure with the addition of fluid to the PRB.

Methods

Ex vivo pressure studies were conducted on Boston Scientific AMS 800 PRBs rated 51-60, 61-70 and 71-80 cmH2O in a controlled laboratory setting using the Laborie Aquarius TT urodynamics system. After calibration of the equipment and appropriate cycling of the balloons in a standardized technique similar to that performed in the operating room setting, PRBs were initially filled to 10mL using 0.9% normal saline and opening pressures were obtained. We reported mean and standard deviation. Balloons were inflated up to 35 mL and pressure-volume data sets were acquired for each device.

Results

The mean opening pressures at 10 mL fill volumes of the 51-60, 61-70, and 71-80 cmH2O PRBs were 51.0±4.8, 65.1±7.8, and 78.9±3.9 cmH2O, respectively. The pressure-volume curves appeared similar for all PRBs and rose to maximum pressures of 67.0±4.0, 87.3±5.1 and 105.7±2.4 cmH2O at fill volumes of 16, 17 and 16 mL, respectively for each type of PRB. The addition of any more volume to the balloons did not result in any additional increase in pressure up to a fill volume of 35 mL (see Figure 1). Following data collection, we continue filling the balloons to a volume of 500 mL. Even at these supra-physiologic volumes, pressures remained stable and only started slowly increasing to 100, 105 and 110 cmH2O respectively at 1 liter.

Conclusions

The AUS PRB is a very compliant device and adding more fluid to an in situ AUS PRB does not increase the pressure of the system. Although our study does not account for in vivo behavior within a possible capsule formation, we discourage this surgeon practice and recommend adopting a different corrective method for persistent urinary incontinence.

Funding

None