Evaluation of peripheral nerve regeneration with a frozen nerve allograft in rabbits

동결 동종신경 이식 후 신경 재생 정도를 육안적, 전기생리학적, 조직학적 방법을 통하여 평가하였다. 실험군으로 가토 10마리를 각 군당 2마리씩 1주, 2주, 4주, 8주, 12주군 등 5군으로 세분하였으며, 가토 안면신경의 협분지를 10mm 제거한 후 신경 결손를 다른 가토 4마리에서 좌골신경을 채취하여 약 6주간 액화질소로 동결시킨 동결 동종신경으로 수술용 현미경하에서 신경외막봉합을 이용하여 수복하였다. 가토 2마리에서 sham수술을 시행하여 이를 대조군으로 활용하였다. 매주 2회 육안적 검사를 시행하였고, 각 군에 대하여 전기생리학 검사와 조직학적 검사를 시행하여 다음과 같은 결론을 얻었다. 1. 육안적 검사에서 이식술을 시행한 부위에서 염증 증상이나 구륜근의 퇴축 등올 관찰할 수 없었다. 2. 실험 1. 2, 4주군의 전기생리학적 검사에서 역치자극, 전도지연 시간 그리고 신경전도 속도는 전혀 기록되지 않았다. 3. 실험 8, 12주군의 전기생리학적 검사에서 실험 8주군의 역치자극, 전도지연 시간 그리고 신경전도 속도가 기록되었으나, 대조군과 실험군 간에는 통계적으로 유의한 차이을 보였다(P<0.05). 4. 실험 1, 2, 4주군의 조직학적 검사에서 신경의 재생을 전혀 관찰할 수 없었다. 5. 실험 8, 12주군 조직학적 검사에서 신경의 재생을 관찰할 수 있었으나, 실험 12주군에서 신경재생의 정도가 현저히 증가하였다.

In this study, nerve regeneration across frozen allograft was assessed using clinical, electrophysiological and histological parameters. Sixteen adult rabbits were used and divided into 3 groups. In group 1 with 10 animals, a 10 millimeter length of the buccal branch of the facial nerve was exposed and transected at the mid portion of face under standard sterile operating room conditions. The defect was repaired with a 10mm frozen allogenic nerve under an operating microscope(Wild Leitz Co., Wild M715) which was procured from the sciatic nerve of four other rabbits of group 2, and then frozen with liquid nitrogen for 6 weeks. The ten rabbits were divided into 1, 2, 4, 8, and 12-week experimental groups. Each group had 2 animals. In group 3 with two animals, a sham operation was performed and they were used as the control group. Animals were observed twice a week, and given electrophysiologic and histologic examinations. The results were as follows 1. On clinical observation, ther was little inflammatory sign at the grafted area, and no muscular atrophy at the orbicularis oris muscle area. 2. In electrophysiologic studies of the 1, 2, 4-week experimental groups, threshold, delay and nerve conduction velocity didn t appear. 3. In electrophysiologic studies of the 8, 12-week experimental groups, threshold, delay and nerve conduction velocity were recorded, but there was a statistically significant difference in the threshold between the control group and the 8, 12-week experimental group(p<0.05). 4. There was a statistically significant difference in the delay between the control group and the 8-week experimental group(p<0.001). 5. There was a statistically significant difference in the nerve conduction velocity between the control group and experimental groups(p<0.01). 6. In histologic studies of the 1, 2, 4-week experimental group, no nerve regeneration could be observed. 7. In histologic studies of the 8, 12-week experimental group nerve regeneration could be seen, but nerve regeneration in the 12-week experimental group was greater than in the 8-week experimental group.