gms | German Medical Science

Objectives/Interrogation: Reported factors historically known to influence outcomes after the repair of peripheral nerve injuries include age of the patient, mechanism of injury, nerve injured, gap length, smoking status, and repair time. Processed nerve allografts (PNA) have been shown to be a safe and effective option to repair nerve gap injuries in a growing number of clinical studies. We sought to evaluate how these factors influenced recovery outcomes of injuries reconstructed with PNA. Here we report from an ongoing international nerve registry on PNA for upper extremity injuries spanning up to 70 mm.

Methods: The database was queried for nerve repairs in the upper extremity using PNA (Avance® Nerve Graft, AxoGen) with sufficient follow-up. An evaluation of outcomes by age, mechanism of injury (MOI), gap length, smoking status, and repair time was conducted. Outcome data were incorporated into the MRC scale for sensory and motor function. Meaningful recovery was defined as S3/M3 or greater on the MRC scale. Further covariate analysis was performed to further characterize the sub-groups. Chi-square analysis and Fisher's exact test were performed with significant difference set at p> 0.05.

Results and Conclusions: The current registry has sufficient quantitative outcomes data on 413 repairs. The mean age was 42 ± 17 (18 - 81) years with mean repair time of 102± 384 (0, 4451) days. The mean gap was 22 ± 13 (3 - 70) mm with an average follow up time of 13 months. Meaningful recovery was observed in 85% of all repairs. No significant differences were found by age, repair time, gap, or MOI overall. Differences were noted when evaluating these factors by nerve type. Significant differences were found by MOI between lacerations and complex injuries in the hand. Non-smokers performed significantly better than smokers in mixed and motor repairs. No related adverse events were reported.

This registry is currently the largest multi-center study on PNA. Analysis of 413 nerve injuries demonstrates meaningful recovery in 85% of repairs. Study wide outcomes are consistent across covariates. Subgroup analysis indicates certain factors such as mechanism of injury and smoking may influence recovery outcomes, but these outcomes are still within expected ranges for nerve autograft and exceeded synthetic conduit historical data. The registry will continue to collect prospective data to help further define the role of PNA in peripheral nerve injuries.