gms | German Medical Science

Objective: Treatment of small intrameatal acoustic neurinomas still is controversial. Hearing and facial nerve preservation by microsurgical tumor resection or the concept of stereotactic radiation therapy or the concept of ”wait and scan” are still under discussion. Also the risk of acute or continous hearing loss should be considered individually.

Method: We had resected 40 intrameatal acoustic neurinomas by a subocipital approach under neuromonitoring in a consecutive group of more than 160 acoustic neurinoma patients. All patients were examined before and after the surgical resection by an otolaryngologist. Hearing function was determined according to the classification of the American Academy of Otolaryngology. Facial nerve function at the preoperative and postoperative site was determined by the classification of House/Brackmann.

Results: 33 from the 40 patients with intrameatal acoustic neurinomas demonstrated functional hearing at the preoperative site (25 x grade A, 8 x grade B). After the tumor resection hearing preservation could be reached in 25 of these patients (15 x grade A; 10 x grade B) which resulted in a rate of hearing preservation of 76%. 39 patients demonstrated full facial nerve function at the preoperative site. Only one patient had a reduced facial nerve function grade III. Facial nerve function at the direct postoperative site was seen 36 x grade I, 1 x grade II, 2 x grade III and 1 x grade IV. Facial nerve function recovered over time demonstrating 38 x grade I, 1 x grade II and 1 x III 6 months after the surgical resection which resulted in total preservation of facial nerve function of 100%.

Conclusions: Intrameatal acoustic neurinomas could be resected under neuromonitoring by a suboccipital approach with a very high rate of facial nerve and hearing function, thus, preservative tumor resection should be considered seriously especially by the risk of tumor related hearing loss.