Model of intestinal continence using an implantable pulse generator and a myoprosthetic sphincter

Past attempts at artificial continence using a wide range of surgical procedures and devices have met with only limited success because of excessive rates of infection, rejection, incomplete continence, and technical difficulty. Presented here is a model of artificial continence using a lumen-occluding Teflon loop powered by the rectus abdominus muscle and activated by an implantable pulse generator. Eight female mongrel dogs underwent laparotomy with creation of a Brooke ileostomy and insertion of a hand-tooled Teflon band around the ileum. The free ends of the loop were sutured, under tension, to the posterior rectus sheath creating extrinsic compression of the bowel by the tightened loop. After denervation of the rectus, stimulating electrodes were implanted and connected to a transcutaneously activated pulse generator (Medtronic SE-4). Stimulation caused contraction of the muscle segment. As the free ends of the prosthetic sling approach each other, the occlusive band loosens, resulting in free drainage of intestinal contents and reduction in intraluminal pressure of the proximal ileum. Withdrawal of current allows for relaxation and return of the muscle to its resting length; this reoccludes the bowel. At 2 weeks, all dogs were continent to solid matter and all but two were continent to liquids. Two dogs developed wound infections requiring drainage. Signal attenuation across the skin resulted in total uncontrollable continence in two dogs because of an inability to transfer sufficient current to the muscle. Direct probe stimulation by an external pulse generator resulted in drainage in these dogs. Necropsy showed no evidence of bowel ischemia in any of the specimens examined at 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)