A Preliminary Assessment of the Utility of Large-Caliber Processed Nerve Allografts for the Repair of Upper Extremity Nerve Injuries

Background: Cabled sensory nerve autografts are the historical gold standard for overcoming gaps in larger diameter nerves as repair utilizing large-diameter autograft risks central graft necrosis. Commercially available processed nerve allograft (PNA) is available in diameters up to 5 mm but represents an acellular 3-dimensional matrix as opposed to viable tissue. The purpose of this study is to specifically evaluate whether similar concerns regarding the use of large-caliber PNA are warranted. Methods: The RANGER Registry is an active database designed to collect injury, repair, safety, and outcomes data for PNAs (Avance® Nerve Graft; AxoGen, Inc, Alachua, Florida) according to an institutional review board–approved protocol. The database was queried for patients presenting with large-caliber nerve allograft repairs in the upper extremity. Identified patients reporting quantitative outcomes with a minimum of 9-month follow-up were included in the data set. Results: The large-caliber PNA subgroup included 13 patients with 15 injuries. The mean ± SD age was 36 ± 22 years. Large-caliber single-stranded repairs included twelve 4- to 5-mm-diameter grafts. Large-caliber cabled repairs included the combined use of 3- to 4-mm and 4- to 5-mm-diameter nerve allografts in 3 repairs. The mean nerve gap was 33 ± 10 mm with a mean follow-up time of 13 months. Available quantitative data reported meaningful recovery of sensory and motor function in 67% and 85% of the repairs, respectively. Conclusion: Although based on a small subset of patients, PNAs of up to 5 mm in diameter appear capable of supporting successful nerve regeneration.