Nerve graft is one of the procedures to be used to overcome a large gap of the peripheral nerve injury.
The survival of the grafted nerve is the most important factor involved with good results. To investigate the sequential change of the blood supply to the grafted nerve, an experimental graft was performed on the sciatic nerve of the rats and change of the local vascularity was observed by microangiography with indian ink. Followings are the results.
1. The specimen of one week, only few vessels were appeared in the grafted nerve, but not avascular. Even in the mid portion, several endoneurial vessels were observed, which seemed to be important for the survival.
2. The vascular system of the epineurium was restored to a normal level at the one or two weeks after, and the perineurial and endoneurial vessels were normalized at three or four weeks after the graft.
3. The perineurial and endoneurial vessels were restored from the two anastomotic sites, but not from the surface of the nerve, and then proceeded to the mid portion.
4. Hypervascularity occurred in the perineurial and endoneurial systems to reach its peak at six weeks, thereafter gradually decreased to the normal level at eight or ten weeks. Transient vasodilatation was observed.
5. The restorated intraneural vascular system showed a diffuse distribution like branches of a tree, but not in parallel pattern as seen in normal nerve.
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