The tumor size limitation in hearing conservation approaches is based upon the observation that useful hearing is almost never preserved following removal of tumors which exceed 2 cm in diameter. This rule need not be adhered to rigidly. It is reasonable to attempt hearing conservation in tumors with even relatively large CPA components when the hearing is particularly good and the IAC is minimally involved. While the probability of success in such cases is very limited, the well informed patient might accept the somewhat higher morbidity of a RS craniotomy in hopes of the remote possibility of maintaining some hearing. The importance of the patient's participation in the treatment planning cannot be over-emphasized.
Intracanalicular tumors deserve special consideration.
In tumors with non-serviceable hearing, the TL approach is selected. Either the RS or MF may be utilized during a hearing conservation attempt to an intracanalicular tumor. Location of the tumor is critical in determining the route employed in approaching intracanalicular tumors with useful hearing. Thus, the MF approach is the only hearing conservation option for these lesions. In tumors which are confined to the medial two thirds of the canal, the RS approach is selected.