Development of a Semifascicle Graft Technique to Bridge Peripheral Nerve Defect: A Case Report and Animal Study.

BACKGROUND: Autologous nerve grafting, the criterion standard for bridging peripheral nerves, can cause complications at the donor site. We investigated a novel approach to reconstruct the nerve gap with a split cross-sectional unmatched semifascicle autograft, which was harvested from the distal part of the injured nerve. METHODS: A patient diagnosed with left-sided frontal branch facial nerve dissection underwent nerve bridging emergency surgery using a semifascicle nerve graft. A sciatic nerve model was used to validate the feasibility and mechanism of this method. Male Sprague-Dawley rats (n = 36) were randomized into (A) intact fascicle, (B) semifascicle, and (C) semifascicle + conduit groups and further subdivided into 4- and 8-week groups for histological analysis of the neurotissue area, fibers, and Schwann cells. The 8-week groups underwent weekly pain and temperature tests; the wet weight of the gastrocnemius muscle was measured after euthanasia. RESULTS: The frontalis of the patient's injured side exhibited movement at 2 months postsurgery and recovered a symmetrical appearance at 13 months. Group A exhibited more neurotissue areas and fibers than groups B and C at week 4; group B had more neurotissue than group C. Group A had greater neurotissue areas than groups B and C at week 8; groups B and C exhibited no differences. The groups displayed no differences regarding nerve fiber, pain, and temperature analysis at week 8. Muscle wet weight of groups A and B exhibited no differences and was higher than that of group C. CONCLUSION: We demonstrated the clinical translational value of semifascicle nerve grafts; the injured site was both the donor and recipient, thereby avoiding donor site damage and associated complications.