Nerve regeneration through a combined autologous conduit (vein plus acellular muscle grafts)

The authors describe nerve regeneration obtained by using a combined autologous conduit, consisting of a vein plus acellular muscle grafts. The right sciatic nerve of seven Sprague Dawley rats was transected for a length of 2 cm and the gap was filled with 2 cm long femoral vein conduit in which two autologous acellular muscle grafts had been previously inserted. Clinical and electrophysiologic tests were carried out twelve weeks after the surgical procedure. The nerve was then removed and a morphological study, including histologic examination, immunohistochemistry and quantitative analysis, was performed. The left sciatic nerve was also removed and used as a control. Regeneration was observed in the middle and distal parts of the conduit in 5 rats. Nerve conduction velocity ranged between 0 and 14.9 ms(-1). In the distal part the nerves were enclosed by a perineurium thicker than their normal counterpart and in which groups of small axons were surrounded by thin myelin sheaths. Quantitative analysis showed that the operated nerve presented a wide variation of the area of the fascicle and the density of the fibres per area, while the diameter of the axons and myelinated fibres showed only small variation, independent of the size of the fascicle. In conclusion, by using this technique, the authors succeeded in obtaining regeneration of a well formed nerve fascicle.