Subcutaneous Ports for Chronic Nerve Cuff and Intramuscular Electrode Stimulation in Animal Models

Area of Science:

• Biomedical Engineering
• Neuroscience
• Surgical Innovation

Background:

• Long-term tracking of nerve injury recovery often requires invasive and frequent assessments.
• Developing minimally invasive methods is crucial for monitoring nerve regeneration over extended periods.

Purpose of the Study:

• To develop and evaluate subcutaneous electrical connection ports (ECPs) for repeated, minimally invasive connection to implanted electrodes.
• To assess the feasibility of ECPs for long-term physiological studies, specifically in laryngeal reinnervation.

Main Methods:

• ECPs were designed and 3D-printed using biocompatible polymers for connection to nerve or muscle electrodes via transdermal needles.
• The system was evaluated in dogs with implanted ECPs and electrodes on recurrent laryngeal nerves and neck muscles.
• Stimulation thresholds, electromyography, and videolaryngoscopy were performed over survival periods up to 32 months.

Main Results:

• ECPs introduced negligible electrical resistance and were reliable and well-tolerated at implant sites.
• The system enabled periodic assessment of nerve and muscle function throughout the study duration.
• Histological analysis revealed minimal tissue reaction and inflammation around the implanted ECPs.

Conclusions:

• Custom-designed ECPs are easily fabricated and demonstrate minimal tissue reaction, facilitating subcutaneous implantation for months to years.
• ECPs provide a reliable and minimally invasive solution for long-term physiological monitoring in nerve repair studies.