Implantable Mechanical Urinary Sphincter

DESCRIPTION (provided by applicant): The purpose of this Phase I Proposal is to develop a means to reduce or prevent capsule formation around an implanted mechanical urethral occlusive device. The mechanical design described in this proposal offers significant advantages over existing methods of restoring urinary continence such as bulking agents and hydraulic cuffs. The current configuation of the device demonstrated good occlusion characteristics in acute studies but became inoperable and ineffective within a one to two month period following implantation due to formation of the fibrotic capsule surrounding the implant. Successful reduction of the capsule would permit continued development of this design which has the following advantages: 1) the ability to remove the occlusive pressure surrounding the urethra when voiding, 2) a unitary construction to simplify surgical insertion, 3) a uniform cuircumferiential application of occlusive pressure that avoids the localized pressure points of the hydraulic device and 4) a permanent restoration of urinary control to both male and female patients. These advantages will reduce complications associated with implanting or injecting permanent partial urethral obstructions such as are introduced by slings and bulking agents and reduce tissue erosion problems associated with implanting hydraulic artificial sphincters. A variety of coating materials designed to reduce inflammatory response and tissue proliferation will be applied to the surface of the proposed implants to ascertain their effectiveness in reducing capsule formation around the prosthesis. Devices coated with anti-inflammatory materials, anti-proliferative materials and with both anti-inflammatory and anti-proliferative materials will be implanted and their response compared to uncoated devices. Successful demonstration of a safe and effective capsule reduction coating material will encourage the continuation into a Phase II study with devices prepared for human implantation.