Surgical Considerations

As it is not the purpose of this chapter to present a technical manual of aural atresia surgery, the extensive details of the surgical procedure are not discussed in this chapter. However, an alternative approach to the anterior atresiaplasty that is now com monly advocated is presented. As described by several surgeons,3-5 the anterior approach involves skeletonizing the posterior temporomandibular joint in order to define the anterior extent of the future canal. Drilling superiorly and following the tegmen medially allows the surgeon to expose the ossicular mass directly and minimize the risk to the facial nerve that will run deep to the ossicles. Initiating the dissection anteriorly and superiorly allows the surgeon to begin creation of the new ear canal (directly) lateral to the middle ear cleft without necessarily creating a large mastoid bowl while still allowing purposeful identification of the facial nerve (as required in all otologic procedures). Alternatively, the repair of an aural atresia can be performed in a more posteriorly based approach. In the severely atretic ear with a thick bony plate; for example, the only identifiable landmarks available to the surgeon may be the middle fossa dura and the sinodural angle. In these cases, identifying these landmarks may allow the surgeon to determine the level of the lateral semicircular canal and subsequently the position of the fallopian canal. Once these landmarks have been identified, completion of the atresia repair can be performed on the basis of the anatomic limitations of the given ear. Again, careful preoperative evaluation of the highresolution computed tomography (HRCT) can provide the surgeon with invaluable anatomic information that can be translated directly to reduced surgical risk to the facial nerve. The routine use of the facial nerve monitor supplements the surgeon's knowledge of temporal bone anatomy, the information provided by the preoperative HRCT, and provides another asset in making unilateral aural atresia repair safer for the patient. We stress the routine use of facial nerve monitoring in all otologic cases, as familiarity with the monitoring devices and experience in interpretation of monitor data is essential to obtaining the maximum information from these tools. The remainder of the surgical technique (ossicular mobilization, tympanic membrane construction, and skin grafting) have been well described elsewhere.3'4

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