The Split Hypoglossal Nerve and Cross-Face Nerve Graft for Dual Innervation of the Functional Muscle Transfer in Facial Reanimation

Facial paralysis is a disabling deformity. The affected individual is seriously affected both esthetically and functionally. Free functional muscle transfer is currently the corner stone in the management of long-standing facial nerve paralysis. Several nerve options are available to supply the free muscle transfer. These nerves can be used alone or in combination. The aim of this work is to study the possibility and results of dually innervating the free functioning muscle transfer. The dual innervation is done using the split hypoglossal nerve and cross-face nerve graft (CFNG) both sutured in an end-to-end manner to the nerve to gracilis. Twenty-nine patients with unilateral long-standing facial nerve paralysis (more than 1 y) were treated using free gracilis muscle transfer dually supplied by the split hypoglossal nerve and CFNG, both sutured in an end-to-end manner. The gained excursion after the free gracilis transfer was 9 to 29 mm (mean: 17.24 mm). A statistically significant increase (P-value=0.0001) in the distance from where the midline crosses the lower vermilion border to commissure occurred from preoperative (mean: 16.55 mm) to postoperative setting (mean: 33.79 mm). Spontaneity was achieved in 26 patients (89.6%). In conclusion, dual innervation of the free muscle transfer using both the split hypoglossal nerve and CFNG (both sutured in an end-to-end manner to the nerve to gracilis) is a good possible option to treat long-standing cases of facial nerve paralysis. It yields adequate muscle excursion with acceptable spontaneity.