Genitourinary prosthetics of the present and future.

Development of implantable prosthetic devices to restore genitourinary function has evolved from applying electrical stimulation techniques for bladder evaluation to adapting fluid energy transfer system for occlusion of the urethra to increase outlet resistance. These hydraulic prostheses have been implanted in several hundred patients in medical centers around the world. The principles behind the operation of this closed-loop system, an some alternative designs that simplify the implant procedure, are described here.