Facial nerve function after microsurgical removal of the vestibular schwannoma

Technological development in microsurgery during the 20th century has led to a significant decline in mortality and morbidity of the surgical management of vestibular schwannoma. Postoperative facial nerve function belongs among the main criteria of success. Retrospective analysis focused on 90 patients undergoing retrosigmoid - transmeatal surgery of vestibular schwannoma during the period of 2010 – 2012. The aim of the study was to evaluate perioperative factors, associated with postoperative facial nerve function. Facial nerve was discontinuous in nine cases (10 %) that were subsequently reconstructed. Position of the facial nerve to the tumor, morphological changes (e.g. elongation and splaying), cystic component of tumor and extent of tumor growth into the fundus of internal acoustic meatus were among the parameters affecting facial nerve preservation. Definitive excellent to good function (House - Brackmann grade1 to 3) was achieved in 96 % of patients in the group with preserved facial nerve continuity. In the group with facial nerve reconstruction there were 67 % of patients with good definitive postoperative function. Stimulation threshold at the end of the surgery brought no significant information about definitive function of the facial nerve, however it predicted early postoperative outcome. Currently it is possible to preserve the facial nerve continuity in the vast majority of surgically managed vestibular schwannomas cases. It is crucial to define prognostic factors influencing the facial nerve injury, and include them into the decision making protocol. For the same reason it is necessary to define factors, which lead to unfavorable outcomes of the facial nerve function despite its anatomical preservation.