Pressure-Volume Measurements on the AMS 800TM Cuff
Condition: Stress Urinary Incontinence
MeSH terms: Urinary Incontinence; Urinary Incontinence, Stress
Study type: Interventional

Summary: 
      he idea of the experiment is to calculate the volume of fluid that is required to raise cuff
      pressure from 20 cmH2O to 120 cmH2O in the American Medical System's AMS 800 Artificial
      Urinary Sphincter (AUS).
    

Detailed description: 
      The current AMS 800 is not personalized to the patient's needs. Most men only need 20 cm H2O
      of urethral compression to remain dry when they are sedentary, yet need 120 cm H2O of
      urethral compression when they are active. The current device compromises with an in between
      pressure - as high as it can be without exceeding safety tolerance thresholds. As such many
      men still leak when they are active. In fact, this compromise is so central to the device
      that a new term has evolved to describe men's suboptimal level of continence after the AMS
      800. We call it "social continence", meaning that they are dry enough to only have to wear
      1-2 pads per day for protection.

      The market is hungry for a device that can adapt to the patient's level of activity, reducing
      the pressure most of the day to protect the urethra and then briefly increasing the pressure
      when he is more active.

      The experimental procedure is explained below and care will be taken to make sure the
      pressure sensor is sterile. The experiment involves minimal risk and will be conducted by the
      PI who has 10+ years of experience in AUS implantations.

      The procedure for implanting the AMS 800 is mentioned in the Operating Manual attached with
      this protocol. The treatment procedure is linked with the experimental setup designed by the
      PI and the research student in the following manner:

        1. Follow surgical preparation steps mentioned on pages 14-15 of the AMS 800 Operating
           Manual. Once the cuff sizer is used to determine the cuff length (usually 4.0cm or
           4.5cm), move on to next step. For graphical representation, follow steps 1 to 9b on
           pages 18- 20 of the AMS 800 Operating Manual.

        2. The AMS 800 cuff is filled with deionized water such that pressure is 20cmH2O. Follow
           steps on pages 13-14 of the AMS 800 Operating Manual for filling the cuff.

        3. The AMS 800 cuff around the urethra has a kink-free tubing which goes into a female
           connector

        4. The female connector connects to the male connector of the IV tubing

        5. The IV tubing is connected to a T-Connector

        6. One end of the T-Connector goes to the TruWave Pressure Transducer

        7. Other end goes to a syringe

        8. The system is pumped with deionized water and is therefore sterile.

        9. Water is pumped into the cuff with the syringe and as the volume in the cuff increases,
           corresponding cuff pressure changes. This is done until we have a volume for a pressure
           reading of 120cmH2O on the pressure transducer.

       10. Once the reading is obtained, the PI will flush out the excess water from the cuff, and
           fill it with an optimal volume as required by the treatment procedure which he has
           performed for over 10 years.

       11. The treatment procedure will continue to follow the steps hereafter as has been designed
           for AUS placement.

      For all other details including device description and post-operative care, refer to the AMS
      800 operating Manual. All devices including the AMS 800 (PMA-P000053) and the Edward
      LifeSciences Pressure Transducer (501K- K142749) are FDA approved.
    

Intervention name(s): AMS 800
Intervention type(s): Device
Intervention description(s): AMS 800 Artificial Urinary Sphincter
Intervention model: Single Group Assignment
Intervention model description: Volume and Pressure Profiles in the AMS 800 cuff. The cuff is filled with deionized water and the amount of fluid in it decides the pressure it will apply while wrapped around the urethra. The pressure-volume profiles will be taken from 6 patients consented by the PI and these will be used for the secondary end point.
Masking: None (Open Label)
Primary purpose: Device Feasibility