Outcomes of Drill Canalplasty in Exostoses and Osteoma: Analysis of 256 Cases and Literature Review

Objective: 1) To describe the surgical technique of drill canaplasty for exostosis and osteoma and to evaluate our results. 2) To propose a new grading system for external auditory canal stenosis (EACS). 3) To review the recent literature. Study Design: A retrospective review. Setting: Quarternary referral center for Otology & Skull Base surgery. Subjects and Methods: Two hundred seventeen patients (256 ears) with exostosis or osteoma were included in the study. Surgical and audiological parameters were evaluated. Results: Mean age was 51.5 (+/- 13.41) years. One hundred sixty nine cases were men and 48 women. Two hundred forty three (95%) cases were exostosis and 13 (5%) were osteomas. According to the proposed grading system, 81% ears had severe or complete stenosis. Seventy eight (30.5%) ears had a concurrent diagnosis of otosclerosis. Retroauricular approach was used in 245 (95.7%). Intraoperative complications included tympanic membrane (TM) perforation seen in four (2%) and mastoid cell exposure in two (1%). Postoperative stenosis/prolonged healing was seen in 11 (4%) patients and required revision in seven cases. Audiologic analysis available for 153 ears-showed the mean change in air-bone gaps (ABG) of 2.18 dB, pure tone averages (PTA) bone conduction (BC) (0.5-4 kHz) of 0.3 dB. Mean healing rate was available for 246 (96.1%) patients and was found to be 6.35 (4-16) weeks. Conclusions: A systematically performed drill canalplasty via retroauricular approach, as described in this article, yields excellent postoperative outcomes as seen in our series. Notably, one-third of exostoses patients in this series, also suffered from otosclerosis. The proposed grading system for EACS enables the surgeon to objectively stage the disease.