Translabyrinthine Approach:
The translabyrinthine approach may be preferred by the surgical team when the patient has no useful hearing, or when an attempt to preserve hearing would be impractical. The incision for this approach is located behind the ear. It involves removing the mastoid bone and some bone in the inner ear, allowing excellent exposure of the internal auditory canal and tumor site. This approach facilitates the identification of the facial nerve in the temporal bone prior to any removal of the tumor. The surgeon, therefore, has the advantage of knowing the location of the facial nerve prior to tumor dissection and removal.
Retrosigmoid/Sub-occipital Approach:
This approach creates an opening in the cranium behind the mastoid part of the ear. The surgeon observes the tumor from its posterior surface, thereby seeing the tumor in relation to the brainstem. When removing large tumors through this approach, the facial nerve can be exposed by early opening of the internal auditory canal. Small tumors can be removed with hope of preserving hearing in some patients through this approach.
Middle Fossa Approach:
This approach is utilized primarily for the purpose of preservation of hearing. A small window of bone is removed above the ear canal to allow exposure of the tumor from the upper surface of the internal auditory canal beyond the inner ear.
The surgeon and the patient should thoroughly discuss the reasons for a selected approach. Each of the surgical approaches has advantages and disadvantages, and excellent results have been achieved using any of the above approaches.
The above is from the ANA website. I'm also enclosing information from another site.
Translabyrinthine
Translabyrinthine is an approach through the mastoid and semicircular canals to the internal auditory canal. The advantages include the following. Few muscles are attached to the mastoid so that there is little muscle pain after surgery. There is an excellent view of the tumor in the internal canal. The surgical approach can be performed relatively quickly. There is little need for brain retraction. Disadvantages include the following. The exposure is relatively small. Removal of large tumors may take longer. Hearing preservation is difficult. Balance preservation is impossible.
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Middle fossa
Middle fossa is an approach above the ear. The advantages include the following. There is an excellent view of the tumor in the internal canal. The chance of preserving hearing and possibly balance function in patients with tumors confined to the internal canal is as good as with any other approach. Disadvantages include the following. The temporalis muscle covering the bone flap is thin. Any irregularity in the bone flap may be felt as an annoying irregularity. The facial nerve often lies between the surgeon and the tumor. In these cases, the nerve must be retracted to remove the tumor. This puts the patient at greater risk of incurring a temporary facial muscle paresis after surgery. Removal of tumors extending beyond the internal canal is difficult because of limited exposure of the cerebellopontine angle.
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Suboccipital
Suboccipital is an approach behind the mastoid. The advantages include the following. There is a large exposure of the cerebellopontine angle, an advantage for removing large tumors compressing the brainstem and cerebellum. The rate of hearing preservation for all sizes of tumor in our series is better than with any other approach. The rate of hearing preservation for tumors confined to the internal canal ranges from 65 to 85% (comparable to the best results reported for middle fossa surgery); tumors extending out of the canal but without brainstem compression from 25 to 45%; and tumors compressing the brainstem about 15% (largest tumor with hearing preservation is 3.5 cm). Proponents of translabyrinthine surgery state that facial nerve preservation is better with that approach; however, in our series facial nerve preservation is as good as with the translabyrinthine approach. We have been able to preserve the facial nerve in all patients with tumors less than 3 cm, and in 90% of patients with tumors 3 cm and larger.
Disadvantages include the following. The cervical muscles must be separated from the subocciput to gain exposure. Muscle pain following surgery is common. One estimate is that 50% of patients will be experiencing headaches at six months after surgery, 25% at one year, and 10 to 15% at two years. Patients with muscle tension headaches prior to surgery are more likely to have headaches after surgery.
Is it possible the doctor mean tRetrosigmoid/Sub-occipital Approach?
Hope this helps
Raydean
