Biomechanical evaluation of an artificial anal sphincter prosthesis.

An artificial anal sphincter was designed to reproduce the normal physiology of the ano-rectum by flattening and angulating the bowel without causing crenation. It was shown in the laboratory that by eliminating crenation, occlusion pressure was evenly distributed without localized high pressure points under the device. Further, the design facilitates the creation of angulation of the bowel in a relatively large area of distribution of the occlusion pressure, allowing the device to be set at lower operating occlusion pressures than that required for circular designs yet still achieve continence. Each of the components of the device was studied separately and the whole system was assessed in an acute and survival animal model.