Fig. 13.1 Temporal bone resection for malignancy encompasses three related procedures of progressively increasing depth: sleeve resection of the external auditory canal (solid line), lateral temporal bone resection (dotted line), and total temporal bone resection (dashed line). The illustration depicts these procedures in the coronal view. Most of these resections are performed for squamous cell carcinoma arising from the external auditory canal. It is generally acknowledged that sleeve resection is an insufficient therapy for malignant disease. In the lateral temporal bone resection, the ear canal is removed en bloc with the tympanic membrane and lateral ossicles. A parotidectomy and/or neck dissection often supplements the temporal bone specimen. In total temporal bone resection, creation of an en bloc specimen is difficult and probably unnecessary. It requires an extensive dissection of the intrapetrous carotid artery, a measure usually of little benefit in deeply invasive squamous cell carcinoma. Most contemporary otologists perform the so-called total temporal bone resection by first carrying out a lateral temporal bone resection and then removing the medial petrous bone piecemeal with a drill. This procedure is indicated for deep extension which penetrates beyond the medial wall of the middle ear and/or mastoid.

Fig. 13.2 Axial view of the three types of temporal bone resection for malignancy: sleeve resection of the external auditory canal (solid line), lateral temporal bone resection (dotted line), total temporal bone resection (dashed line).

Fig. 13.3 At the beginning of the temporal bone resection for ear canal malignancy, the ear canal is transected and the meatus sutured closed. The lateral margin is sent for frozen section. Note that the technique employed is different from that used during skull base surgery (see 12.5 Ear Canal Closure). Simply sewing the tragal skin to the conchal margin permits resection of the skin of the entire ear canal. To break the spring of the conchal cartilage, it is crosshatched with a scalpel.

Fig. 13.4 After transection of the cartilaginous canal just medial to the meatus, a ring of skin and cartilage is harvested from the specimen side and sent for frozen section analysis. If tumor is seen in the specimen (uncommon), then further resection of the meatus and pinna is performed as necessary. To discourage spillage of tumor cells, the meatus is sewn shut. An intact canal wall mastoidectomy is then performed with opening of the facial recess (for technique, see 7.5 Facial Recess Approach). FR, facial recess.

Fig. 13.5 Working via the facial recess, the incudostapedial joint is severed sharply. A disposable myringotomy knife is a convenient tool for accomplishing this maneuver.

Fig. 13.6 The bone bridge separating the epitympanum from the facial recess is then drilled away and the incus is removed. The tensor tympani muscle also needs to be transected (not shown here).

Fig. 13.7 The descending portion of the fallopian canal is then skeletonized, leaving a thin bony covering. Identification of the position of the facial nerve is important for the next step during which the facial recess opening is then extended inferiorly into the hypotympanum.