[A preliminary study on the morphological changes of the microvasculature following the peripheral nerve...

The microvasculature of peripheral nerve following autografting was studied by scanning electron microscopy. The newly-formed capillaries was also examined by transmission electron microscopy. Capillaries of a fascicle were divided into an extrafascicular vascular plexus and an intrafascicular capillary bed; the former capillaries formed networks, while the latter capillaries ran longitudinally and formed slightly spiral curve. Normal intrafascicular capillaries had tight junctions, a continuous basement membrane and pericytes. On the suture line, capillaries of the graft and those of the host were connected by newly developed sinusoidal capillaries, which were formed at the extrafacicular region earlier than at the intrafascicular region. Newly developed sinusoidal capillaries were transformed into glomerulus-like capillaries and formed fine networks. These networks exhibited a normal capillary architecture after reconstruction. The endothelium of newly-formed capillaries showed a discontinuous basement membrane at the early stage of regeneration. An intrafascicular capillary bed was present in the middle part of the graft.