The distal branches of the facial nerve are sometimes severed in various forms of trauma. These distal branches respond to repair differently than do the main trunk or other peripheral nerves. Actual axon counts must be done to determine the percentage of regrowth rather than measuring nerve diameter.
Physiologic and histologic techniques were used to analyze sheathing and suturing techniques in the repair of facial nerve branches in rabbits. Repair sites were examined at various intervals up to four months after repair. Very small suture material (10-0) must be used. Vein sheaths and silicone elastomer (Silastic) sheaths caused decreased axon regrowth, and strictures occurred when silicone elastomer sheaths were used. Seven stitches provided the best results in terms of axon regrowth, prevention of neuromas, and return of function. Three sutures or a continuous stitch produced poorer overall results.