Urovalve, Inc. has developed a user operated valved catheter to enable people with chronic urinary retention to pursue more active lives and decrease the high incidence of urinary tract infections. The device is a short silicone catheter with a malecot to retain it in the bladder and a miniature proximity valve to control flow. The tiny fluid flow valve is opened by a switching magnet that is held near the body and closes when the magnet is moved away. The device is inserted into the urethra without surgery, is extracted easily, and will be intended to be replaced every 28 days. This research will perform feasibility tests on the intraurethral valved catheter to: refine clinical techniques for insertion and extraction; demonstrate stability of catheter positioning in urethra; demonstrate that the device works effectively and is safe during a short-term trial. Five spinal cord injured subjects having urinary retention but otherwise normal urethras will receive implants and be monitored for four days within a rehabilitation hospital. The stents will bridge the urethral sphincters from bladder neck to bulbous urethra. Subjects will perform normal daily living activities to test stability of stent placement and will be monitored for clinical signs, residual volumes and understanding of valve operation. Subjects will open the valves intermittently using hand held actuator magnets. Implantation methods, using a protective sheath, and removal methods, using an extraction tool, will be tested for safety. Implanted stents will be monitored for: migration from implant position; urine leakage; clogging; and closure due to stent deformation. Stent extraction forces will be measured and recovered stents will be examined for accumulation of renal debris and physical integrity and be cultured for bacteria accumulation. Devices currently available are either very simple catheters (Foley or Intermittent Catheter) or very high tech electro-mechanical devices that require extensive surgical implantation. No inventions currently available or in development combine the utility and health-care cost benefits of Urovalve's invention. ? ? ?