In Vivo Performance and Biocompatibility of an Intelligent Artificial Anal Sphincter System

Severe fecal incontinence is an embarrassing and psychosocially debilitating condition that has a considerable negative impact on quality of the life. This article describes an intelligent artificial anal sphincter system (AASS) based on enteric cavity pressure signal feedback mechanism and its in vivo experiment in two dogs. The optimized AASS consists of an external telemetry unit, internal artificial anal sphincter (IAAS) and transcutaneous energy transfer charging system (TETCS). The new sphincter prosthesis was designed with pressure sensor to simulate the part function of the external anal sphincter. The devices were implanted in two dogs and studied for periods of up to 5 weeks. The efficacy of the device in achieving continence and sensing the stool was assessed. The biocompatibility and biosecurity, including blood supply of the rectum, blood serum chemistry, and histologic examination of tissue, were evaluated during and after experiment. Results of the chronic animal experiment demonstrated no significant tissue inflammation. Functionality and biocompatibility of the improved device have been proved.