Peripheral Nerve Regeneration by Tissue Engineering for Prevention of Misdirection

Abstract

We created an artificial nerve conduit called a “polyglycolic acid tube” based on a basic concept of in situ tissue engineering to achieve complete functional regeneration without misdirected reinnervation. We successfully achieved functional regeneration of the recurrent laryngeal nerve in dogs using this artificial nerve conduit. Based on our results, we began its use in human clinical application to regenerate peripheral nerves (such as the recurrent laryngeal nerve, facial nerve, and chorda tympani nerve).

Functional regeneration was observed in the recurrent laryngeal nerve with a shortest defect of 10 mm (n = 1/6). Sufficient functional regeneration was observed in cases with a defect of the peripheral branch of the facial nerve: the temporal branch alone or both temporal and zygomatic branches (n = 2/2). However, when the defects were in the main trunk of the facial nerve, the recovery was only to a House-Brackmann grade II or III (n = 4/6) and misdirected reinnervation could not be prevented. Functional regeneration (sense of taste) was observed in half of the defects of the chorda tympani nerve (n = 4/8).