The effect of omental wrapping on nerve graft regeneration.

We have performed 1 cm long nerve grafts in the sciatic nerves of 60 Wistar rats. In 30 cases (n = 30) the grafts were wrapped in omentum. We have studied the nerve regeneration accomplished after 30 and 90 postoperative days from the histological and neurophysiological points of views. Survival of the omentum has been excellent. The histological assessment showed a higher blood vessel population as well as a higher count of axons in the cases where the nerve graft was wrapped in omentum. Areas with neural fibrosis, which are a sign of poor vascularisation, were smaller in the cases with omentum. The amplitude of the contraction in the gastrocnemius muscle was higher in the cases where omentum was used. The endothelial cells of the omentum synthesis fibroblast growth factors (acid and basic) which, due to their angiogenic and neuronotrophic properties, may be the cause of the beneficial effects of omentum on peripheral nerve regeneration.