Side-to-end hypoglossal-facial anastomosis via transposition of the intratemporal facial nerve.

The technique of facial nerve repair with side-to-end hypoglossal-facial anastomosis is presented and evaluated in five patients who were operated on for facial nerve paralysis after acoustic schwannoma surgery, or had cranial base trauma. The end-to-end hypoglossal-facial anastomosis is accompanied by hemilingual paralysis, with difficulty in swallowing, chewing and speaking. In this new technique, the facial nerve is mobilised in the temporal bone, transected at the second genu and transposed to the hypoglossal nerve where a tensionless side-to-end anastomosis is performed. The hypoglossal nerve is transected in oblique fashion to about one third of its circumference. We were able to achieve a tensionless anastomosis in all patients. The idea is to bring about re-innervation of the previously denervated tissue via a collateral sprouting of axons of the donor nerve through the site of coaptation without sacrificing the innervation of the donor nerve's original targets. With side-to-end hypoglossal-facial anastomosis, two patients attained a House- Brackmann grade of III (one of them with independent movement of eyelids and mouth); one achieved grade IV, another grade V and grade VI. No patient had hemilingual atrophy nor any problems associated with swallowing or chewing.