Exostoses of the external auditory canal.

The otoscopic view is that of a left ear with a single large globular sessile exostosis that almost completely obstructs the ear canal. The surgical approach is similar to that for canal skin tympanoplasty. The patient is placed under a local or general anesthetic, and the surgeon works through a speculum. An incision is made in the normal portion of the ear canal. The canal skin and periosteum are elevated from the bone of the exostosis until there is no space for the instruments to move medially. The bone is then removed with a small drill or curette until enough space is again made to elevate more skin toward the annulus. This procedure is repeated by alternately removing bone and elevating skin and periosteum until the entire exostosis has been removed and the ear canal has a normal contour.

Care must be taken not to damage the canal skin with the drill or curette. The skin is left attached by a pedicle on its medial side. At the end of the procedure, the canal skin is placed over the newly contoured external auditory canal. The ear canal is filled with Gelfoam, which has been soaked in an antibiotic aqueous steroid suspension, to hold the pedicle skin flap against the bone. During bone removal, care should be taken to avoid exposing a large area of the glenoid fossa. The use of a postauricular incision for the treatment of exostoses offers no advantage. In fact, it can give the surgeon a false sense of security.