Neurosurgery 1992-98 July 1992, Volume 31, Number 1 73 Facial Nerve Repair by Interposition Nerve Graft: Results in 22 Patients Clinical Study AUTHOR(S): Stephanian, Erick, M.D.; Sekhar, Laligam N., M.D., F.A.C.S.; Janecka, Ivo P., M.D., F.A.C.S.; Hirsch, Barry, M.D. Departments of Neurosurgery (ES, LNS) and Otolaryngology-Head and Neck Surgery (IPJ, BH), University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania Neurosurgery 31; 73-77, 1992 ABSTRACT: RESECTION OF TUMORS of the posterior cranial base may incorporate a segment of the facial nerve because of tumor infiltration, or may result in unplanned nerve injury. Immediate repair of the facial nerve by resuture or with an autogenous nerve graft is highly desirable to ensure optimal recovery of facial function. Twenty-four patients who underwent extensive surgery of the posterior skull base and facial nerve reconstruction were studied. Of these, 12 patients had preoperative facial weakness and 3 had facial palsy. All patients underwent graft reconstruction from the subarachnoid or labyrinthine portion of the facial nerve to the fallopian or extracranial segment. The greater auricular nerve was used as a graft in 14 patients, and the sural nerve in 10. Two patients died of their disease soon after surgery, and, therefore, were excluded from our follow-up. In the remaining 22 patients, the median follow-up time was 20 months. As evaluated by the House-Brackmann grading system, 45% (10/22) of the surviving patients achieved a good recovery of facial function, 36% (8/22) attained a fair recovery, and 18% (4/22) had minimal or no recovery. There was no statistical correlation between the length of the graft used and the degree or timing of clinical recovery. The surgical result obtained in all patients with complete preoperative facial palsy and in one patient with dense facial paresis was poor. KEY WORDS: Facial nerve; Nerve repair; Skull base tumor During surgery of the posterior cranial base, excision and grafting of a segment of the facial nerve may be indicated under the following conditions: 1) when the facial nerve is incorporated in the three-dimensional radical resection of extensive malignant tumors of the temporal bone; 2) when the nerve is found intraoperatively to be invaded by or firmly attached to locally infiltrative malignant or benign tumors; and 3) when there is iatrogenic injury to a segment of the 7th nerve during the surgical manipulation. Loss of facial expression can have devastating consequences for the patient; therefore, the therapeutic approach to these aggressive tumors of the skull base should include the reconstruction of the facial nerve. Immediate repair of the discontinuity in the facial nerve is important to allow for optimal as well as timely recovery of facial function. The objectives of surgical repair of the facial nerve include reestablishment of facial symmetry and elements of facial expression, while preventing uncontrolled movements. If there is a wide gap to be bridged, and the proximal and distal stumps of the facial nerve are viable, autogenous nerve grafting provides the best results (5) . Although multiple factors may contribute to the survival and success of these grafts (4,8,10,12,13) , several factors are of paramount importance: the use of atraumatic microsurgical technique in the handling of neural tissues, the avoidance of tension at the anastomotic sites, and the provision of adequate vascularity to the nerve graft by means of reconstruction of the cranial base with vascularized tissue. The present report focuses on the surgical technique used, and the evaluation of results in 22 patients in whom the facial nerve was grafted after extensive skull base surgery. An overview of different surgical techniques used in facial reanimation is also presented, and the issue of a uniform grading system of recovery is discussed. PATIENTS AND MATERIALS During a 4-year period, 24 patients (14 males and 10 females) underwent reconstruction of the facial nerve with a graft during operations for cranial base lesions. These operations were performed by a neurosurgeon (LNS) and an otolaryngologist (IPJ or BH). The mean age of patients was 46 years (range, 19 months to 67 years). As seen in Table 1, 9 patients had normal preoperative facial function, 12 had mild to moderate facial paresis, and 3 had complete preoperative facial palsy. The duration of preoperative facial paresis in the 12 patients with this level of function was less than 1 year in 6 patients, 1 to 2 years in 4 patients, and more than 2 years in 2 patients. The duration of complete preoperative facial paralysis was 6 months in 2 patients and 2 months in another. Our patients harbored a variety of tumors (Table 2); most commonly, a segment of the facial nerve was incorporated within the en bloc resection of the temporal bone for malignant squamous cell carcinoma. Many patients, however, had histologically benign but biologically aggressive tumors that had recurred despite multiple previous attempts at excision. Patients were selected for surgery if clinical and imaging studies (computed tomography and/or magnetic resonance imaging) disclosed extensive tumor in the middle and posterior fossa or neoplastic invasion of the temporal bone. In five cases, a lengthy segment of the facial nerve was grafted after resection of the temporal bone for invasive malignant squamous cell carcinoma. In 18 patients, a graft was performed after tumor removal including excision of a tumor-infiltrated segment of the nerve. One additional patient had the facial nerve grafted after inadvertent injury to the nerve during tumor removal. The greater auricular nerve was used as an interposition graft in 14 patients and the sural nerve was used in 10. Athough grafts of varying lengths Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.