Abstract
We thank Dr Hetzler for his comments. We agree that techniques to minimize drilling volume should be employed to reduce the risk of high-frequency hearing loss. At our institution, diamond burrs are used for this procedure. High-frequency hearing loss at 4 kHz in our series was an infrequent (<5%) complication, and there were no ears with more than a 30-dB worsening at this frequency, with no new cases of tinnitus. We feel that the other aspects of our technique, including the postauricular approach to achieve the proper operative trajectory, identification of the temporomandibular joint anteriorly, preservation of the external auditory canal skin, and avoidance of the ossicular chain, are equally paramount in avoiding complications. These points are especially important when operating on near-totally or totally occluded canals, as is the case in almost all of the ears operated at our institution.
The improvement in air-bone gap from preoperative to postoperative was from 7.9 dB to 3.6 dB, and this was statistically significant. This excluded the patients who underwent simultaneous stapedotomy. The mean time to postoperative audiometry was 5.4 months, but some patients were tested when the ear canal was still undergoing final healing. It is possible that this caused a slight residual air-bone gap. In addition, as discussed in the paper, there is a published association between exostoses and otosclerosis,1 and it is possible that there were some patients who had persistent air-bone gaps due to otosclerosis.
Packing of the external auditory canal is performed with pieces of pressed gelatin sponge soaked in antibiotic drops. The senior author allows patients to swim or surf at one week with a silicone earplug, and has had no untoward events as a result of this.
Correction of exostosis remains a challenging procedure, but we feel that complications may be minimized with the proper surgical approach and attention to meticulous surgical technique.