Peripheral nerve allograft: how innovation has changed surgical practice

Abstract

The landscape of available technology and surgical technique has changed over the last several decades, thus leading to changes in the peripheral nerve repair surgical algorithm. Neurorrhaphy is a common procedure; however, it is well recognized that nerve repair should be performed tensionless, thus preventing the ability to perform direct repair with a nerve gap. Historically, nerve gaps were repaired with autograft. However, autograft surgery has been associated with complications such as numbness and chronic pain, which left surgeons searching for alternatives. Nerve allografts were first utilized in the 1800s but failed due to the immune response. In the modern era, they were again utilized in the 1980s, but did not gain popularity because of the need for the use of immunosuppressants. It was evident through the 1990s that continued innovation in peripheral nerve repair was needed, as studies showed that only approximately 50% of patients with nerve gap repair achieved good or excellent outcomes. In the 2000s, the advent of an engineered nerve allograft (Avance® Nerve Graft) changed the landscape of peripheral nerve repair. Early clinical evaluation of Avance showed that adequate sensation was able to be achieved in nerve gaps up to 30 mm, providing an alternative to autografts. As engineered nerve allograft use became more conventional, studies showed 87.3% meaningful recovery in nerve gaps up to 50 mm. Furthermore, recent studies have shown that gaps between 50-70 mm have shown 69% meaningful recovery. While technology and surgical technique continue to improve, these results are promising for large nerve gap repair.