Surgical Technique

The general surgical technique for atresiaplasty has been described elsewhere.3'10 A few selected highlights are discussed below.

Facial nerve monitoring is used for every case. We always use the anterior approach—the most direct approach to the epi-tympanum and ossicular mass. Before drilling the external auditory canal, we explore the posterior bony wall of the temporomandibular joint to guide the proper angle of drilling, to locate the anterior extent of drilling, and to ensure that the facial nerve does not exit the temporal bone through the joint. Drilling is started at the cribriform area. The mastoid tegmen/middle fossa plate is identified and followed medially. We recommend a cylinder with a diameter of 12 mm for size. Care is taken to open as few mastoid air cells posteriorly as pos sible. The facial nerve can take an aberrant course and be encountered posteriorly or inferiorly while drilling. Preopera-tive planning and identification of the entire course of the facial nerve on the HRCT will eliminate any surprises. If the facial nerve is too far anterior in the tympanic segment/second genu (i.e., coursing over the footplate), the patient may not be a candidate for atresia surgery. We do not recommend facial nerve rerouting in these cases.

The epitympanum is next opened and the malleus/incus complex is identified. At this point, drill trauma to the ossicular mass must be minimized or a high tone sensorineural deficit may result (approx. 5% incidence4). The laser has been very useful in freeing the ossicles from bony adhesions and ligamentous attachments in the middle ear space. The ossicular chain must be mobile; we prefer to graft over the malleus/incus complex whenever possible, rather than remove it and place an ossicular replacement prosthesis. Freeing the ossicular mass from all attachments, as well as drilling bone away from the mass, is crucial in preventing refixation.

The reconstructive technique of Jahrsdoerfer has withstood the test of time.1,20 A 0.009-inch split-thickness skin graft is harvested from the hypogastrium and is prepared by cutting 4 to 5 triangles in one edge. The tips of the triangles are marked for placement medially on the temporalis fascia. The fascia is cut to a 20 X 15-mm oval, and small tabs are cut anteriorly and superiorly for placement under the protympanic periosteum to prevent lateralization. The fascia is lain over the ossicular mass, and the bony canal is completely lined by the skin graft with the triangles and marks placed over the fascia. The entire bony canal must be covered with skin. A thin disk of Gelfilm is used to hold the skin and fascia in place and to create an anterior tympanomeatal angle. The canal is lined with two small strips of Silastic sheeting and packed with a Cor-tisporin-soaked Ambrus wick.

The meatoplasty is made 10 mm in diameter by removing cartilage, and the skin graft is brought through and sutured to the native skin. Interrupted tacking sutures of 5-0 Ticron are used at the four quadrants, followed by a running suture of 60 fast absorbing gut placed between the Ticrons. A second Ambrus wick is used to secure the meatus. Improvements in tympanoplasty grafting, the addition of the laser to minimize drill trauma and ossicular manipulation, and facial nerve monitoring have significantly improved surgical results over the last 10 years.

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