The Treatment Dilemma of Small Acoustic Neuroma and the Role of Hearing Preservation Surgery

The small acoustic neuroma, defined by a dimension of < 10 mm in the CPA and between 1 and 10 mm in the internal auditory canal, may be treated with the following three different strategies: expectant management, microsurgery, and radiosurgery. A wait-and-see strategy often results in a hearing loss, even when growth is absent. Stereotactic radiosurgery carries a very low risk for the seventh nerve and a progressive hearing loss. Surgery has a very low risk for the seventh nerve, allowing hearing preservation in about 50% of selected cases. Our surgical experience in 318 cases, operated on with the hearing preservation technique from 1976 to 2007, shows a progressive improvement of results. From 1976 to 1999, there were 207 cases with 28% preserved; from 2000 to 2001, we had 53 cases with 36% preserved; and from 2002 to 2006, 58 cases had 68% of hearing preserved.

Conclusion: We suggest retrosigmoid surgery with retrolabyrinthic drilling of the meatus in cases of neuroma with normal or slightly impaired hearing function. We use a wait-and-see strategy if the patient has impaired hearing function and the neuroma has a diameter < 15 mm. We use radiosurgery according to the neuroma's diameter, age of the patient, his or her general condition, and the patient's desires.