Which End is Up? Terminology for Terminolateral (End-to-Side) Nerve Repair: A Review

By convention, we "come from" and "go to." A flap has a donor site and goes to a recipient site. A transplant comes from a donor and goes to a recipient. Neural regeneration proceeds from proximal to distal. It seems most appropriate then for a nerve repair description to follow this logical order. Therefore an "end-to-side" repair would mean that the donor nerve, the nerve that is providing the axons with which to neurotize the recipient nerve, should be the nerve named first. An end-to-side repair would therefore require that the nerve whose end is sutured into the side of the recipient nerve be the nerve that is bringing the proximal axons to regenerate distally, for whatever that purpose may be, sensory or motor. A side-to-end repair would therefore require that the nerve whose side is sutured to the end of the recipient nerve be the nerve that is bringing the proximal axons to regenerate distally, for whatever that purpose may be, sensory or motor. The full descriptive phrase must include whether the intent is to reinnervate a skin target and is, therefore, a sensory repair, or to reinnervate a motor target. The names of both the donor and the recipient nerves must be specified. Illustrations of these logical possibilities are shown in this review of the modern history of "end-to-side" or "side-to-end" nerve coaptations.