Nerve repair by means of vein filled with muscle grafts. II. Morphologicalanalysis of regeneration

The morphological features of regeneration in long-distance (3 cm) muscle-v ein-combined grafts were experimentally investigated in the rat sciatic ner ve by means of light and electron microscopy. In the early phases of regene ration (14 days after surgery), many regenerating nerve fibers were detecte d along the muscle-vein-combined graft. Six months after surgery, quantitat ive morphometrical analysis of myelinated nerve fibers showed that both the total number and density of myelinated nerve fibers were significantly gre ater in regenerated nerves than in control nerves. The contrary appeared tr ue for the mean fiber size, with fiber size significantly smaller in regene rated nerves. Ultrastructural observations allowed the description of some peculiar aspects of the relationship between muscle fibers, nerve fibers, a nd Schwann cells in both early and late phases of regeneration. (C) 2000 Wi ley-Liss, Inc.