The blood supply of the hypoglossal nerve and its relevance to carotid endarterectomy

Since the hypoglossal nerve is liable to injury during carotid endarterecto my and similar procedures, its blood supply was examined in microinjection studies of human cadavers. The nerve is supplied by arteries that arise fro m the ascending pharyngeal artery as it exits from the hypoglossal canal, t he occipital artery as the nerve passes under its branch to the sternomasto id muscle, direct branches from the external carotid artery, and branches f rom the ascending pharyngeal artery just near the bifurcation of the common carotid artery. Within and close to the tongue, the nerve is supplied by b ranches from the lingual artery. Damage to the vessels supplying the nerve may account for some cases of hypoglossal palsy after carotid endarterectom y. Possible mechanisms are ischaemia, thermal or electrical injury from dia thermy current conducted to the nerve, or intraneural haematoma from ruptur ing one or more of these fine vessels. (C) 1999 The international Society f or Cardiovascular Surgery. Published by Elsevier Science Ltd. All rights re served.