采用神经纤维梳理技术显示神经端侧缝合后侧支再生的研究

COLLATERAL SPROUTING AT END-TO-SIDE NEURORRHAPHY SITE DEMONSTRATED BY NERVE FIBERS MICRO-TEASE TECHNIQUE

目的探讨一种可直接显示神经端侧缝合后神经纤维侧支再生的方法。方法取5只成年Wistar大鼠,将右侧腓总神经切断,远端与外膜开窗的胫神经作端侧缝合。术后3个月切取缝合部位神经和对侧正常胫神经,福尔马林、锇酸和甘油处理后,于手术显微镜下剥离结缔组织,将神经纤维梳理出,并在光学显微镜下观察其形态。另切取缝合口及其远端的腓总神经作组织学检查。结果神经端侧缝合口分离出的神经纤维,可见在郎飞结附近发出细小侧芽,而正常胫神经则未发现。缝合口纵切片见神经纤维从胫神经进入腓总神经,缝合口远端腓总神经横切片见大量再生纤维。结论采用神经纤维梳理技术可直观地显示神经端侧缝合后神经纤维侧支再生的现象。

Objective To develop a technique that can directly demonstrate collateral sprouting of intact nerve fibers at end-to-side neurorrhaphysite. Methods Five Wistar adult rats were used in this study. The common peroneal nerves at one side were sectioned at the level of knee joint, and their distal ends were sutured to the tibial nerves after removal of a 1 mm-diameter window in the epineurium. Three months after the operation, the nerve segments at neurorrhaphy site and the normal tibial nerves at the contralateral site were harvested. The specimens were fixed in 10%formaldehyde and post-fixed in 1% osmium tetroxide, then macerated in glycerol. Single fiber was teased out in pure glycerol under an operative microscope, then transferred to a slide and observed under light microscope. The nerve segments at neurorrhaphy site and distal peroneal nerves were also harvested for histological evaluation. Results At the neurorrhaphy site, small nerve fibers sprouted from a donor nerve fiber near node＇s of Ranvier. While such phenomena were not found in normal tibial nerve. From the longitudinal section of neurorrhaphy site, bundles of nerve fibers ranged from tibial nerve to peroneal nerve were observed. Lots of regenerative nerve fibers emerged in distal peroneal nerve. Conclusion The phenomena of collateral sprouting at end-to-side neurorrhaphy site can be demonstrated directly by nerve fiber micro-tease technique.