Morphometric study of the cervical course of the hypoglossal nerve and its application to hypoglossal facial anastomosis.

The hypoglossal nerve is used classically in salvage of facial paralyses in the absence of spontaneous recovery. A variety of ways of transferring and suturing the hypoglossal nerve to the distal segment of the facial nerve have been reported. In order to determine which mode of reconstruction is the best for neurotisation of the facial nerve, the caliber of the hypoglossal nerve was studied in ten subjects at the level of proximal and distal parts of the trunk and the cervical loop. The fascicular surface area of the cervical branch is inadequate for use. The distal extremity of the hypoglossal nerve has an ideal caliber to be sutured to the facial nerve trunk and the proximal part is large enough to allow partial harvesting of the hypoglossal nerve for neurotisation of the facial nerve.