Research on a novel flexible bionic artificial anal sphincter.

Area of Science:

• Biomedical Engineering
• Medical Devices
• Gastroenterology

Background:

• Fecal incontinence treatment faces challenges with existing artificial anal sphincters due to complex mechanics, high failure rates, large size, and poor biocompatibility.
• A novel flexible artificial anal sphincter with a bionic structure is proposed to overcome these limitations.

Purpose of the Study:

• To develop and evaluate a novel flexible artificial anal sphincter with a bionic structure.
• To address the mechanical and biocompatibility issues of current artificial anal sphincter devices.

Main Methods:

• The artificial anal sphincter design mimics the puborectalis muscle and uses flexible tendons for transmission.
• Thermoplastic urethane and medical silicone ensure good biocompatibility, small size, and light weight.
• Finite element analysis simulated rectal interaction, analyzing anorectal angle and stress during traction.

Main Results:

• An anorectal angle of <90° effectively controls defecation, preliminarily verifying device efficacy.
• At a 71° traction angle with the intestinal tube closed, maximum equivalent stress was 148.45 kPa, below safety thresholds.
• Maximum and minimum principal stresses (88.37 kPa and 82.74 kPa) were also within safe limits, confirming device safety.

Conclusions:

• The novel flexible artificial anal sphincter shows potential for reducing stress between the device and the rectum.
• The bionic design improves biomechanical compatibility, offering a safer and more effective treatment for fecal incontinence.