成年大鼠4种脊髓全横断方法的比较
作者：王春婷，游思维，刘惠玲，陈秉耀，焦西英，孟晓梅，吴宗亮，鞠躬
【关键词】脊髓切断术
关键词: 脊髓切断术;神经纤维;空洞;轴突再生;大鼠
摘要:目的比较成年大鼠4种脊髓全横断方法对后肢运动功能及脊髓组织学的影响. 方法 32只成年SD大鼠分为A，B，C和D4组，每组8只，分别以4种不同方法全横切T9脊髓.A组以尖刀片自左向右横行一次性切断脊髓;B组将尖刀片自脊髓背部中线处垂直插入并分别向两侧缓慢细心切断脊髓;C组将一丝线穿过脊髓腹侧硬膜外腔，以长刃显微剪一次性完全横断脊髓，并将丝线由断端间隙中拉出;D组以尖刀片自脊髓背侧至腹侧分层快速划断脊髓，再抬起脊髓两断端以验证横断的完全性.术后1h肉眼观察脊髓形态变化，8wk时评估截瘫后肢自发性运动功能恢复后，处死动物，取脊髓损伤节段，行连续矢状冰冻切片，小鼠抗神经丝抗体免疫组化染色，光镜下观察有无神经纤维的残留或再生，以及空洞及瘢痕的形成. 结果 A，B两组术后脊髓肿胀、外翻，8wk时分别有50%，38%的动物出现程度不等的功能恢复，镜下可见成束残留纤维和大量空洞.C，D两组术后脊髓外观良好，8wk时无功能恢复和残留纤维，但有少量神经丝免疫反应再生纤维.与D组相比，C组断端间隙较大且空洞较多. 结论经作者创新的D组方法，横断完全、损伤较小，为简便易行、效果可靠的脊髓全横断手术
方法.
Keywords:cordotomy;nerve fibers;cavities;axonal regen-eration;rat
Abstract:AIM To compare the effects of four spinal cord transecting methods on spontaneous motor recovery in para-plegic hindlimbs and histological changes within the spinal cord in adult rats.METHODS Thirty-two adult male SD rats were divided into Groups A，B，C and D（n=8for each group，which received one of the four methods of spinal cord transection at T9）.In Group A，the spinal cord was tran-sected with a sharp blade along the inner wall of the vertebral channel.The blade in Group B，however，was vertically in-serted through the cord at midline and guided to slowly and carefully cut the bilateral halves of the cord separately.In Group C，the cord was cut with a pair of long-edge microscis-sors，and the completeness of the transection was verified by guiding a surgical suture through the ventral extradural space before and pulling the suture out through the gap between the2stumps of the transected cord.The cord of Group D an-imals was dissected with a sharp blade in quick gashes，and complete transection was checked by uplifting one
of the stumps.The appearance of the exposed spinal cord was ob-served with naked eyes1h after the surgery，and the locomo-tor recovery of the hindlimbs was evaluated with the BBB rat-ing scale at8wk after surgery before sacrificing all animals.The damaged spinal cord segments were sectioned sagittally，prepared for anti-neurofilement immunostaining，and ob-served under a light microscope for any possible remaining and regenerating nerve fibers as well as the formation of cavi-tation and scars.RESULTS Spinal cord edema and ectropi-on could be encountered1h after the surgery，and50%and38%animals showed different degrees of locomotor recovery and corresponding remaining nerve fibers with many scars and cavities8wk following the surgery in Groups A and B.As for Groups C and D animals，a better appearance of the cord without much edema and ectropion was observed at1h and no locomotor recovery could be revealed at8wk.A few neurofilament-positive regenerating，but not remaining，fibers were observed within the lesion site.Group C animals had a wider gap between the two stumps of the transected spinal cord and more cavities in the injured spinal segments than those animals in Group D.CONCLUSION The authors’innovated transecting method in Group D is easy and reliable because of its properties of the completeness of tran-section and。