Facial Nerve Repair by Laser Nerve Welding

초록

The aim of this study is to elucidate the effectiveness of laser assisted nerve anastomosis using CO2 laser in head and neck area, and to compare the nerve regeneration between microsurgical suture and CO2 laser repair by immunohistochemical method with cholera toxin B as a retrograde tracer. In 12 rats, the buccal branches of facial nerve in both sides were transected and epineural welding using CO2 laser was performed in right side and microsurgical suture was performed in left side. In 6 rats of 12 rats, at 4 weeks later from operation , cholera toxin subunit B was injected into epineurium, where was distal to the nerve anastomosis site. In other 6 rats of 12rats, at 8 weeks later, the same procedure was performed. And in another 6 rats, in which no operation was performed, cholera toxin subunit B was injected into normal buccal branch of facial nerve as a control. Then immunohistochemical detection of retrogradely transported cholera toxin was performed and the number of positively labeled neurons in facial nucleus was counted. The counts of labled neuron in facial nucleus were a little more in laser assisted nerve anastomosis than microsurgical method, but, there were significant difference only at 4 weeks, no difference at 8 weeks. And none of 12 rats showed dehiscence of laser welding site. This study shows laser repair of facial nerve in rat is at least equal or more successful to microsurgical suture in effectiveness of nerve regeneration and advantages of laser repair in head and neck surgery indicate a need for further study.