The objective of this program is to develop of a new prosthesis for the treatment of total urinary incontinence. The prosthesis is magnetically operated with an externally worn permanent magnet. The magnet compresses an implanted metal bellows, which pressurizes a urethral cuff to stop the flow of urine. The cuff pressure is set at the time of implantation, but is is later percutaneously adjustable using an injection port on the body of the reservoir. The advantages of this device includes simplicity, mechanical reliability, ease of use, and safety. Failure of the implant does not result in urethral blockage, and the prosthesis an be used by patients with poor dexterity, both limitations of existing devices. The fluid reservoir/bellows assembly is encased in a silicone rubber jacket which employs a microporous textured surface to limit tissue encapsulation of the prosthesis which might alter the device function over long periods of time. Prototype devices will be constructed, and the performance of the cuff and magnetic actuation system studied in vitro. To access the safety of the external magnet, A series of animal experiments will be performed using miniature pigs to study the potential for skin trauma. The experiments will be of 6 weeks. Upon completion, the skin and subcutaneous tissue under the external magnet will be examined for evidence of pressure necrosis, and the tissue capsules from the microporous surface will be examined histologically and compared with smooth surface control implants. The new device is likely to be especially useful for elderly patients.
| Fukumura, F; Harasaki, H; Fukamachi, K et al. (1993) Development of a magnetically operated artificial urethral sphincter. Chronic effects of compression on the skin structure and blood flow. ASAIO J 39:M283-7 |
