Managing the nerve gap: New tools in the peripheral nerve repair toolbox

Abstract

End-to-end repair of a peripheral nerve transection injury remains the gold standard. Delayed repair, nerve debridement and early functional mobilisation may all increase repair site tension, which impedes axon regeneration and must be avoided. Prompt diagnosis, referral to a specialist and exploration can minimise the nerve retraction, debridement and gap size, and societal benefit will be achieved through adopting a standardised approach to management. However, early exploration may provide challenges in defining the extent of the injury zone and therefore the adequacy of nerve debridement. Repair site tension can be reduced with 'sutureless' nerve approximation in a conduit, interposition of autologous graft or with interposed processed nerve allograft. Sutures can be avoided through interposition de-tensioning grafts and use of tissue glues. However, a large gap in a conduit will not support robust regeneration and grafts have two neurorrhaphy sites for axons to negotiate. Autologous graft has a donor site morbidity that may be unacceptable. An algorithm for peripheral nerve reconstruction should include the use of conduits and allograft as de-tensioning devices, avoiding the morbidity associated with autologous nerve grafting.