[Nerve regeneration through a venous graft in the rat. Preliminary results]

An experimental study of nerve regeneration in rats was realized after sectioning 8 mm of the sciatic nerve and interpositioning a vein-graft to replace the portion of nerve which has been removed. The vein-graft was taken at the neck level, far away from the point of suture between vein and nerve, a procedure which seems to prevent the problems of scabbing. A histological and electrophysiological analysis was carried out on 16 grafts, over periods ranging from 4 weeks to 4 months. The nerve and venous dissections were realized under a stereoscopic microscope. A certain degree of amyotrophy appeared in the external-posterior region of the thigh, directly related to the muscular dissection and the partial paralysis caused by the section of the common peroneal nerve. The electrophysiological recordings in vivo provide proof of nerve regeneration but reveal the absence of any correlation between the time of recovery and the time of induction. Examination under the light microscope confirms the regeneration of the nerve inside of the vein-graft, with an augmentation of myelin sheaths, which increase with time both in number and in thickness. The vein-wall acts as a guide but the passage of a few nervous filaments outside of the graft itself is observed. Examination under the electron microscope furnishes important information on myelin sheaths. The results are of excellent quality, but to better appreciate and evaluate them, we envisage a further study, this time to be carried out on another animal species.