Facial neurorrhaphy with autologous sural nerve graft using the CO2 laser in a primate model.

Cranial nerves, being of fine caliber and having a poorly defined epineurium, pose problems in intracranial sutural anastomosis. The CO2 laser is a comparatively new prospect that is being evaluated for sutureless neural anastomosis. Because there are no reports on the laser anastomosis of a peripheral spinal nerve to a cranial nerve, we designed this study to explore the possibility of performing a laser anastomosis of the facial nerve, using an autologous sural nerve graft in a primate model. Six monkeys underwent resection of the right facial nerve in the parotid fossa. In five of them, the CO2 laser was used to anastomose sural nerve interposition grafts by the use of microsurgical techniques. In one control animal, the sural nerve graft was interposed between the cut ends of the facial nerve and no anastomosis was performed. Compound muscle action potentials were recorded preoperatively and 2, 4, and 6 weeks postoperatively. At the end of 6 weeks, the wound was again explored and the grafts were examined. The neurophysiological results showed that in the five laser-welded nerves, at 4 weeks and 6 weeks postoperatively, the proximal latencies showed an improving trend with each successive recording. It was concluded that the CO2 laser can be used for the anastomosis of interposition grafts to the facial nerve.