Clinical outcome following nerve allograft transplantation

The clinical outcome of seven patients who underwent reconstruction of long upper- and lower-extremity peripheral nerve gaps with interposition peripheral nerve allografts is reported. Patients were selected for transplantation when the nerve gaps exceeded the length that could be reconstructed with available autograft tissue. Before transplantation, cadaveric allografts were harvested and preserved for 7 days in University of Wisconsin Cold Storage Solution at 5 degreesC. In the interim, patients were started on an immunosuppressive regimen consisting of either cyclosporin A or tacrolimus (FK506), azathioprine, and prednisone. Immunosuppression was discontinued 6 months after regeneration across the allograft(s) was evident. Six patients demonstrated return of motor function and sensation in the affected limb, and one patient experienced rejection of the allograft secondary to subtherapeutic immunosuppression. In addition to providing the ability to restore nerve continuity in severe extremity injuries, successful nerve allografting protocols have direct applicability to composite tissue transplantation.