Experimental Models and Clinical Tools to Assess Nerve Regeneration and Functional Outcomes

Abstract

The success of vascularized composite allotransplantation (VCA) is dependent on adequate peripheral nerve regeneration for optimal outcomes. Because so much of the benefit derived from VCA is derived from peripheral nerve regeneration, systematically monitoring this process clinically is of utmost importance, particularly with regards to determining prognosis. As such, more attention must be placed on developing new strategies to enhance peripheral nerve regeneration and graft innervation. The clinical evaluation of nerve regeneration can be complex due to the multiple problems that nonfunctioning nerves may cause. Indeed, a nonfunctional nerve does not only cause problems from absence of function but may impart unique impairment from pain, sympathetic, and/or sudomotor dysfunction. Therefore, evaluation of nerve regeneration should combine functional testing, patient outcome reported testing, and more objective neurophysiologic and/or imaging-based testing. This chapter provides an overview of the experimental as well as clinical methodologies available for the evaluation of peripheral nerve repair and regeneration with special attention placed on nerve regeneration in the setting of VCA.KeywordsVascularized composite allotransplantation (VCA)NerveAxonDenervationNerve regenerationNerve allotransplantationNerve graftingNerve conduction studyElectromyographyTinel’s signWallerian degeneration