Determining the maximal length of a vein conduit used as an interposition graft for nerve regeneration

Although autogenous veins have been used as nerve conduits (AVNCs) both experimentally and clinically for short nerve gaps up to 3 cm, investigators have not as yet determined the maximal effective length for functional nerve regeneration. In addition, the role of the distal nerve stump on subsequent nerve growth remains unclear. A rabbit peroneal nerve AVNC model was used to study axonal regeneration through nerve gaps of 1 to 6 cm. After allowing ample time for nerve regeneration, clinical, electrophysiologic, and neurohistologic studies were performed to evaluate nerve growth and functional muscle reinnervation. Comparisons were made with 6-cm conventional nerve grafts. Excellent growth and function were found with AVNCs up to 3 cm in length, with increasing incapacity for regeneration at lengths greater than 3 cm. The distal nerve stump is believed to play a vital role in nerve regrowth.