Management of nerve gaps: Autografts, allografts, nerve transfers, and end-to-side neurorrhaphy

Abstract

Since its introduction in the late 1870’s, surgical restoration of function following peripheral nerve injury has made significant progress (Naff and Ecklund, 2001). The development of the operating microscope, improved microsurgical techniques, and a greater understanding of the internal topography of perpheral nerves has greatly improved functional outcomes. In addition, advances in basic science and clinical research have furthered our understanding of the pathophysiology of nerve injury, recovery, and repair. There are several factors that influence recovery following a nerve injury: time elapsed, patient age, mechanism, proximity of the lesion to distal targets, and associated soft tissue or vascular injuries (Gilbert, et al., 2006, Hentz and Narakas, 1988, Slutsky, 2006). All these factors must be carefully considered in order to optimize the operative approach used in each unique patient. Prompt repair of nerve injuries leads to improved outcomes by allowing for earlier distal motor end plate and sensory receptor reinnervation. In younger patients, the more robust regenerative capacity typically results in better outcomes compared to the elderly. Mechanism of damage is an important determinant of the longitudinal extent of the injury. More proximal lesions must traverse longer distances to reinnervate the distal target. And finally, concomitant soft tissue or vascular injuries can result in significant distortion and scarring, seriously complicating exploration of the affected area. The ultimate goal of any peripheral nerve reconstruction is the restoration of function as promptly and completely as possible, while minimizing donor site and systemic morbidity. In cases where a tension-free primary end-to-end neurorrhaphy is not possible, several alternatives exist. This review summarizes these options for repair including interpositional nerve grafting, transfers and end-to-side neurorrhaphy (Fig. 1). Open in a separate window Figure 1 Summarizes the various options for nerve repair. Nerve allografts are utilized for large, otherwise irreparable injuries. Nerve transfer use redundant nerve fibers for a proximal nerve injury. The autograft is used to reconstruct a nerve gap. Direct repair is used when there is no intervening nerve gap to create tension. Both end-to-side and nerve conduits are used for noncritical sensory injuries.