The reasons for end-to-side coaptation: how does lateral axon sprouting work?

Abstract

Nerve fibers are attracted by sutureless end-to-side nerve coaptation into the recipient nerve. Opening a window in the epineurium enhances axon attraction and myelination. The authors analyze the features of nerve repair by end-to-side coaptation. They highlight the known mechanisms of axon sprouting and different hypotheses of start up signals (presence or absence of an epineurial window, role of Schwann cells, signaling from the distal trunk). The clinical literature is also presented and differences between experimental and clinical applications are pointed out. The authors propose their point of view and perspectives deriving from recent experimental and clinical experiences.

Keywords

• peripheral nerve repair; nerve coaptation; end-to-side nerve repair; side-to-side nerve repair; epineurial window; Schwann cells; nerve regeneration; nerve babysitter procedures; nerve transfer; nerve graft; glues in nerve repair