A Retrospective Case Series Reporting the Outcomes of Avance Nerve Allografts in the Treatment of Peripheral Nerve Injuries

Background: Acellular nerve allografts are a viable treatment modality for bridging nerve gaps. Several small studies have demonstrated results equal to those of autologous grafts; however, there is information lacking with regard to outcomes for wider indications. The authors evaluated the outcomes of patients treated with a nerve allograft in a variety of clinical situations. Methods: A retrospective chart analysis was completed between April of 2009 and October of 2017. Inclusion criteria were age 18 years or older at the time of surgery and treatment with a nerve allograft. Patients were excluded if they had not been followed up for a minimum of 6 months. The modified Medical Research Council Classification was used to monitor motor and sensory changes in the postoperative period. Results: Two hundred seven nerve allografts were used in 156 patients; of these, 129 patients with 171 nerve allografts fulfilled the inclusion criteria. Seventy-seven percent of patients achieved a sensory outcome score of S3 or above and 36 percent achieved a motor score of M3 or above. All patients with chronic pain had improvement of their symptoms. Graft length and diameter were negatively correlated with reported outcomes. One patient elected to undergo revision surgery, and the original graft was shown histologically to have extensive central necrosis. Anatomically, allografts used for lower limb reconstruction yielded the poorest results. All chronic patients had a significantly lower postoperative requirement for analgesia, and allografts were effective in not only reducing pain but also restoring a functional level of sensation. Conclusions: This study supports the wider application of allografts in managing nerve problems. However, caution must be applied to the use of long grafts with larger diameters.