One-stage removal of residual intracanalicular acoustic neuroma and hemihypoglossal-intratemporal facial nerve anastomosis: Technical note

OBJECTIVE AND IMPORTANCE: Incomplete removal of residual intracanalicular tumor and injury to the facial nerve are the main problems associated with surgery of large acoustic neuromas via the retromastoid suboccipital approach. In patients with residual or recurrent intracanalicular neuromas, the translabyrinthine approach is the preferred surgical route, allowing complete tumor removal; it may eventually also be used for exposure of the intratemporal portion of the facial nerve for a hemihypoglossal-facial nerve anastomosis when a postoperative facial palsy exists This one-stage procedure has not been described previously. CLINICAL PRESENTATION: Three patients with postoperative facial palsy and residual intracanalicular tumor after surgical removal of a large acoustic neuroma via the retromastoid suboccipital approach underwent reoperation via the translabyrinthine approach and one-stage removal of the residual tumor and hemihypoglossal-facial nerve anastomosis. All three patients had a complete facial palsy of House-Brackmann Grade VI and a residual tumor of 8 to 12 mm. TECHNIQUE: A classic translabyrinthine approach was used to open the internal auditory canal and remove the residual intracanalicular tumor. The facial nerve was exposed in its mastoid and tympanic parts, mobilized, and transected; then, the long nerve stump was transposed into the neck and used for an end-to-side anastomosis into the hypoglossal nerve. The operation resulted in variable improvement of the facial muscle function up to Grade III (one patient) and Grade IV (two patients). CONCLUSION: Reoperation via the translabyrinthine approach is indicated for removal of residual intracanalicular acoustic neuroma and realization of a hypoglossal-facial nerve anastomosis in a single procedure. It is suggested that this type of anastomosis may also be used during the initial operation for acoustic neuroma removal when the facial nerve is inadvertently sectioned.