Structure features of the temporal bone in patients with acquired post-inflammatory atresia of the external auditory canal

Objective: Comparative analysis of the structure of the external auditory canal (EAC) according to computed tomography (CT) scans of the temporal bones in patients with acquired post-inflammatory atresia of the EAC and patients with safe chronic suppurative otitis media (SCSOM) without atresia. Patients and methods: 42 patients (43 ears) with acquired post-inflammatory atresia of the EAC and 11 patients (22 ears) with bilateral SCSOM without acquired atresia were included in the study. Based on the original axial СT images and multi-planar reformation images were measured: thickness of the anterior wall in bony part of EAC; anterior tympanomeatal angle and the distance from the lateral process of the malleus to the anterior wall of an EAC; lumen of the EAC in front of the tympanic sulcus. Results: The lumen of the bone part of the EAC in patients with acquired post-inflammatory atresia is 17,0% less than in patients with SCSOM without atresia; patients with acquired post-inflammatory atresia have a more acute anterior tympanomeatal angle (33° versus 68°) than patients with SCSOM without atresia. The thickness of the anterior wall of the EAC in the bone part in patients with acquired post-inflammatory atresia of the EAC does not statistically differ from the analogous parameter in patients with SCSOM without atresia. Conclusion: The revealed results indirectly indicate the presence of certain features of the structure of the external ear in patients with acquired post-inflammatory atresia of the EAC such as narrower anterior tympanomeatal angle and lumen of the bone part. These features of the EAC structure may contribute to the more likely development of post-inflammatory atresia development.

Surgical Treatment of Acquired Atresia of the External Auditory Ear Canal

Introduction Acquired atresia of the external auditory canal is characterized by the formation of fibrous tissue in the medial part. The causes include chronic otitis externa, perforated chronic otitis media, postoperative or idiopathic healing problems. Acquired atresia presents with hearing loss and can be associated with otorrhea. Objective We analyzed the results of surgery after six months and two years by checking (1) pre- and postoperative hearing thresholds; (2) presence of otorrhea; and (3) whether a dry and patent ear canal is achieved. Methods We conducted this retrospective study at a tertiary referral center. In total, 27 ears underwent treatment with resection of the fibrotic plug followed by transplantation of a split-thickness skin graft covering the bare bone and tympanic membrane. When necessary, we combined this with a myringoplasty and a (meato-) canalplasty. Results Otorrhea was present in 59.3% of the patients initially and in 14.8% at six months and 11% at two years postoperative. A dry and patent ear canal was obtained in 55.6% after six months and in 89% of the patients after two years (n = 27). The pure tone average before surgery was 39.1 dBHL (SD = 20 dBHL), at six months 31.4 dBHL (SD = 16.4 dBHL), and at 24 months postop 30.9 dBHL (SD = 17.1 dBHL). We observed a statistically significant improvement of hearing in 63% of the patients at six months (p = 0.005) and in 65% after two years (p = 0.022). Conclusions Treatment of acquired atresia remains a challenge. Using the appropriate surgical technique, including skin-grafting and regular postoperative check-up, rendered excellent results regarding otorrhea and a moderate improvement of hearing was achieved in 65% of the patients after two years.