Peripheral Nerve Surgery : AlloGrafts and Conduits ( Alternatives to Autografts ? ) in Peripheral Nerve Regeneration

This article provides a review of some recently published studies, which share the search for a valid alternative option to the use of autologous nerve grafts in peripheral nerve repair. Five are experimental animal studies and the last reports on a clinical experience in humans. The first two papers studied the effectiveness of allografts compared with the classic use of autografts in animals transiently treated with FK 506 (Tacrolimus), an immunosuppressant with neuroregenerative and neuroprotective effects. The following three papers studied artificial conduits filled with cells. In the first of these papers, a nerve conduit of trimethylenecarbonate-co-epsilon-caprolactone was filled with autologous Schwann cells. In the second paper, the authors used artificial conduits filled with bone marrow stromal cells-derived Schwann cells. In the third paper, the artificial conduits were filled with blood-derived CD133+ cells. The last paper is a retrospective analysis of surgical outcomes in 5 patients with brachial plexus birth injury treated with an artificial conduit made of a biological material, a collagen matrix tube (Neurogen). At the end of this review, the role of autologous nerve autografts as the gold standard for peripheral nerve repair still remains. Allografts must resolve definitively the problem of rejection and immunosuppressant therapy. Conduits made of no biological materials filled with the cells cited in the reviewed papers are not competitive with nerve autografts and even with allografts. Collagen matrix conduits in humans seem competitive with nerve autografts for short nerve gaps (less than 2 cm).