Facial nerve function after surgery for removal of acoustic neuroma by the extended middle cranial fossa approach.

Abstract

Postoperative facial nerve function was evaluated in 98 patients operated on by the middle cranial fossa approach or the extended middle cranial fossa approach from June 1976 to April 1985. In this series, the smaller the tumor size at the time of the initial surgery, the better the postoperative facial nerve function was. The facial nerve was preserved in 83.4% of the 79 patients who were subjected only to the initial surgery. However, total removal of the tumor along with facial nerve preservation was achieved only in 70.8%. Anatomical preservation of the facial nerve was possible in 78% of 87 patients. The postoperative functional results among patients in whom facial nerves were anatomically preserved were satisfactory (facial expression score of 75% or higher, i.e., 30 points or more out of a possible 40 points) in 70-80% of the patients with small size or intracanalicular tumors, but, in less than 50% of the patients with tumors of medium size or larger. There is a need to obtain higher rates of functional preservation as well as higher rates of satisfactory functional results. At the present stage, we must strive to achieve earlier diagnosis so that surgery can be performed while the tumor is still medium-sized or small.