Experiences with an artificial sphincter to establish anal continence in dogs

An implantable device for establishing urinary continence has been developed and has received FDA approval (AS 800, American Medical Systems, Inc.). The authors have applied this device to the control of anal continence in dogs. Fifteen mongrel dogs underwent either anal sphincter disruption (7) or abdominal-perineal resection (8). Such animals have bowel movements almost hourly. In each case, the device was implanted at the time of surgery. In dogs with working cuffs and disabled or absent sphincters, continence was maintained in seven out of 15 animals for periods of 4-8 hours. After cuff activation, intraluminal cuff pressures of 50-70 cm of water achieved continence for a period of 8 hours. In animals sacrificed from 1 to 12 months after implantation, the device was found to be well tolerated by the body with minimal fibrosis of the mucosa or muscularis of the bowel. Complications observed in the same four out of 15 animals during the study period were infection, device extrusion, and device malfunction. Infection resolved with local wound care and antibiotics (3/4) and the device was successfully replaced in two out of four instances of extrusion. With cuffs of proper size and pressure, this appliance may be effective in the control of human anal incontinence via the establishment of continent perineal colostomies following an abdominal-perineal resection.