Experimental Study On Reimplantation Of Nerve Root To The Spinal Cord After Root Avulsion Of Brachial Plexus In Rats

Although it has been over two hundred years since the brachial plexus injury was recognized and treated, the curative effect of the root avulsion of brachial plexus has been bad and it is still one of difficult problems in clinical medicine over the world. Reirnplantation of nerve root to the spinal cord is beening paid attention and regarded as one of effective methods of treating the root avulsion of brachial plexus in future. Reimplantation of avulsed nerve root is rather difficult, which involves problems to be studied. At first, a rational animal model should be established. Then, the results of reimplantation should be evaluated in according to morphological and functional restoration. Meanwhile, research on methods to accelerate nerve regeneration and improve functional restoration after reimplantation of nerve root is also necessary. This project aimed at these targets and used rats to go along resarch. [Objective] 1. To establish a rational model for studying reimplantation of nerve root to the spinal cord after root avulsion of brachial plexus in rats. 2. To evaluate nerve regeneration and reinnervation of target-organ functionally and morphologically after reimplantation of nerve root to the spinal cord. 3. To explore the effect of FKb5O6 on enhancing nerve regeneration and promoting functional restoration after reimplantation of nerve root in the spinal cord. [Methods] l .Under operation microscopy, the C6 root was avulsed and the spinalcord was exposed via an anterior aPproach. The musculoculaneous nerve wascut at the level of interface between the bundles and branches of the brachialplexus, then to harvest the nerve, 30mm long, from the ulnar nerve forbridging the distance between the distal extremity of the musculocutaneousnerve and the spina1 cord. The proximal extremity of the grafed nerve wasimplanted lmm into the spinal cord at the C6 ventral root efltYy zone.Thegeneral situation of the forelimb and hind1imb of the operating side wereobserved after surgery After 3 months and 6 months, Whether the graftednerve was tored from the spinal cord and there was laceration at site of nerveanastomosis were examined under operation microscoPy or by HE staining.2. The animal models of reimplantation of nerve root to the spinal cordwere made in 24 SD rats. After 3 months and 6 months, the MC nerveregeneration and fUnional restoration of brachial biceps were evaluated byretrograde labe1linig study with True Blue tracing, electrophysiologialexamination, functional assessment, muscle wet weight and the histologicalexamination.3. The models of reimPlamation were made in 48 SD rats. They wererandomly divided iflto experimental grouP and control group.Accordings tothe postoperative interval of 3 months and 6 months, each group weresubdivided into tWo subgroups. The experimental group were given FK506lmg/kgid by infusing into stomach and the control group were givennothing. Biceps MAP, muscle contraction strength, muscle wet weight andHE staining of muscle and nerve were examined to determine and comparethe morphological and functional difference between the two grouPs.[ Rcsults 11. All animal survived well. There were not tumefaction, necrosis,exulceratio, exuviation in fOrelimb and not palsy in hindlimb. After 3months and 6 months, neither the nerve tearing from the spinal cord nor thenerve rending at the site of nerve anastomosis was observed by microscopicdissection or HE staining.2. At the 3rd month and 6th month, the neurons labelled by TB werefound in the ventral horn of the spinal cord. The functions of t...