End-to-side neurorrhaphy: the mechanism of nerve regeneration

神经端侧吻合后神经再生的机制尚不清楚。手术后神经再生有三种可能性。首先，在手术中受损的神经会在移植的神经上再生。第二，受者神经旁发。第三，侧枝发芽后，再生神经逐渐修剪，避免双重支配。有人建议采用双标记技术或使用y型硅胶管的间隙模型从供体神经中萌发侧枝的可能性。通过完整的非损伤大鼠模型，我们证明了轴突萌发来源于完整的供体神经侧支。解剖成年wistar大鼠坐骨神经，移植于左右正中神经之间。A组采用无损伤技术将受体神经与分离的供神经端侧吻合。B组将这些神经包裹在筋膜内，并进行无伤性神经缝合。C组在缝合处取出神经外膜，然后进行神经缝合。术后30天和60天，我们用前臂双侧屈肌肌电图评估神经再生情况。为了进行形态计量学评价，解剖出共合蛋白位点，荧光染料（DiI）晶体附着于采集的供神经近端。37度孵育3周。我们在共聚焦显微镜下观察了该标本的横截面。即使在一个完整的非损伤模型中，神经也可以电物理再生。荧光染料（Dil）染色了接合部位以外的再生神经。这些结果支持在端侧吻合中，供体神经侧支再生神经。

The mechanism of nerve regeneration after the end-to-side neurorrhaphy is yet to be studied. There are three kind of possibilities of nerve regenerating after the procedure. First, the nerve which was damaged through the procedure regenerates to the transplanted nerve. Second, recipient nerve sprouts collaterally. Third, after the collateral sprouting, the regenerated nerves were pruned gradually to avoid double domination. Some suggested the possibility of collateral sprouting from the donor nerve by the double-labelling technique or the gap model using the Y-shaped silicone tube. With the complete non-injury rat model, we proved that the axonal sprouting originates from the intact donor nerve collaterally. The sciatic nerve of adult wistar rat was dissected and transplanted between the left and right median nerve. In group A, recipient nerve was neurorrhaphied end- to-side with the divided donor nerve by non-injury technique. In group B, these nerves were wrapped in the faascia and neurorrhaphied non-injuriously. In group C, the epineurium was removed at the suture site and then neurorrhaphied. Thirty and sixty days after the operation, we evaluated nerve regeneration with electromyography of bilateral flexor muscle at the forearm. For morphometric evaluation, coaptatoin site was dissected out and fluorescent dye(DiI) crystal was attached to the proximal side of the harvested donor nerve. It was then incubated in 37 degree for 3 weeks. We observed cross section of this specimen under a confocal microscope. Even in a complete non-injury model, nerve regenerated electrophysically. Fluorescent dye(Dil) stained the regenerated nerve beyond the coaptation site. These results supported that in the end-to-side neurorrhaphy the nerve regenerated by the collateral sprouting from the donor nerve.