Wednesday, October 29, 2003 - 8:20 AM

An Evaluation of a Collagen-Based Nerual Conduit Xenograft

Anureet K. Bajaj, MD, David Creamer, BA, Allen Gabriel, MD, and Subhas Gupta, MD, PhD.

Introduction: The standard approach to primary nerve repair has been an end-to-end suture technique. Larger nerve gaps, neuromas, and delayed injury presentations may require nerve grafting techniques, including nerve conduits to perform a tension-free repair. A nerve conduit provides the framework for the regenerating axons, and, ideally, would dissolve with a minimum of scar tissue rendering a second operation unnecessary. Recent work has shown the efficacy of polyglycolic acid nerve conduits for nerve repairs with gaps of 4 cm or less in digital nerves. Other autogenous or alloplastic materials have been evaluated as conduits and have demonstrated inconsistent and sometimes unacceptable results. A biologic conduit consisting of bovine-derived collagen in an acellular matrix has been developed and evaluated in a simian model showing efficacy equal to that of direct suture repair. However, its use in humans has not been well described. The purpose of this study is to show the efficacy of the collagen xenograft nerve guide in humans for the repair of traumatic nerve injuries of the upper extremity. Materials and Methods: Since January 2002, we have exclusively used the collagen xenograft nerve guide to repair traumatic upper extremity nerve gaps from 1 to 3 cm at our institution. These patients are being evaluated for sensory and motor recovery using two-point discrimination, Semmes-Weinstein monofilament testing, and EMG/NCS analysis at 3-, 6-, and 12-month intervals. Also, they were assessed for complications including bleeding, infection, painful scar, extrusion, delayed wound healing, allergic reaction, hypersensitivity, and evidence of nerve compression. Results: Eighteen nerves (twelve patients), with nerve diameters ranging from 2.0-7.0 mm, were repaired using the collagen xenograft nerve guide. The mean nerve gap was 2.54 cm (SD 0.36mm). No extrusions, allergic reactions, or other conduit-related complications were reported. Electrical and sensory testing data demonstrating rates of re-growth will be presented. Conclusion: The collagen xenograft nerve guide is a viable alternative to nerve grafting for nerve repairs with nerve gaps from 1 to 3 cm.