8 Transcortical Exposure of the Epitympanum
Definition
The transcortical, full exposure of the epitympanum, generally carried out after a cortical mastoidectomy. Alternatively, it may be called epitympanotomy.
Indications
The main indication is in the surgery for chronic otitis media with cholesteatoma.
Anatomical Orientation

Surgical Steps
The cortical mastoidectomy and posterior tympanotomy have been completed. The temporal bone is ready for epitympanotomy. In chronic otitis media surgery, an epitympanotomy or epitympanectomy is carried out with or without a posterior tympanotomy, depending on the needs of the case.
DR: Digastric ridge
EAC: External auditory canal
MCF: Middle cranial fossa (dural plate)
SS: Sigmoid sinus (dural plate)

The zygomatic root is identified and using a medium-sized cutting burr, the bone in this area is removed. Care should be taken not to damage the dura of the middle cranial fossa superiorly and the superior wall of the external auditory canal inferiorly.
II: 3–4mm cutting burr
MIL: Zygomatic root
ZR: Zygomatic root

Following extirpation of the lateral bone at the zygomatic root, the exposure is widened. The medial bone, which is close to the incus and malleus, is left untouched until the final stage of the procedure.

Definitions and Tips
- Epitympanum (attic): Definition: The superior part of the tympanic cavity. Tips: The epitympanum comprises the area medial to the pars flaccida and scutum, and includes the head of malleus, the body of incus, and the surrounding structures. It is divided into two parts by the cog—the anterior epitympanum (supratubal recess) and the posterior epitympanum.

