Chapter 7: Extended Facial Recess Approach

The Extended Facial Recess Approach (EFRA) is a surgical technique designed to provide enhanced access to the hypotympanum and protympanum. This approach requires modification of the traditional facial recess procedure by extending it to the level of the tympanic annulus, often necessitating the sacrifice of the chorda tympani nerve. Such an extension allows better visualization of critical structures within the middle ear, including the hypotympanic cells and the promontory.

Key Landmarks

To perform this approach effectively, the following anatomical landmarks must be identified and preserved, except where removal is necessary:

• Facial nerve
• Chorda tympani nerve
• Annulus (tympanic ring)
• Tympanic membrane
• Digastric ridge

Surgical Steps

1. Chorda Tympani Transection:
   The chorda tympani nerve is transected at its origin from the facial nerve. This step allows further dissection along the vertical segment of the facial nerve within the fallopian canal.
2. Bone Removal:
   • Using a diamond burr, the bone between the posterior external auditory canal (bony annulus) and the fallopian canal is carefully removed.
   • The thinning of this area, referred to as the facial ridge, exposes the sinus tympani, improving surgical access.
3. Visualization:
   Through the extended recess, key structures such as the hypotympanic cells and promontory become visible. Additional landmarks, including the lenticular process of the incus (Li) and the posterior canal wall (PCW), must be noted for orientation.
4. Inferior Extension:
   • The inferior opening of the recess is expanded by sculpting the external auditory canal (EAC) cortex lateral to the chorda tympani until the tympanic annulus is visible.
   • The annulus is followed posterior-inferiorly, and all bone between the annulus and the vertical segment of the facial nerve is removed.
5. Anterior Extension:
   • If the inferior cortex of the EAC is adequately thinned, the recess can be further expanded anteriorly.
   • This step facilitates visualization of the Eustachian tube opening, enhancing access to the protympanum.

Clinical Significance

The Extended Facial Recess Approach is particularly useful in cases requiring detailed visualization and access to deep middle ear structures, such as in chronic otitis media or cholesteatoma surgery. By carefully removing bone and extending the facial recess, surgeons can access areas previously obscured while maintaining the safety of critical neurovascular structures.

Caution

Despite its benefits, the EFRA involves potential risks, particularly the permanent loss of chorda tympani function, which may result in altered taste sensation. Additionally, meticulous attention is required to avoid injury to the facial nerve.