Congenital aural atresia surgery: anterior mastoid and transmastoid approaches

Background Aural atresia (CAA) is a congenital abnormality with hypoplasia or aplasia of the external auditory canal. Surgical procedures of CAA is not only difficult but has still not been embraced by surgeons. Many surgeons are doubtful to perform a repair due to poor hearing results and the risk of new canal stenosis. This article describes the writers’ expertise with surgical management of aural atresia. A retrospective study of 16 cases of CAA was undertaken in the Hearing and Speech Institute between 2015 and 2018. The study consisted of 16 patients, 8 patients for each group, 10 males and 6 females between 4 and 18 years of age with a median age of 6 years. Ten patients had bilateral atresia, and 6 had unilateral atresia. Postoperatively, patients were tested for hearing recovery and follow-up lasting up to 2 years to record any complications. Purpose of the study was to compare hearing effects and risks of anterior and transmastoid approaches to external and middle ear restoration in patients with CAA. Results All patients were satisfied with the surgery by improving the hearing up to 35 dB or less after 12 months. Four patients (25%) developed soft tissue meatal stenosis, with 2 patients in each group. There were no cases of bony canal stenosis. TM perforation was seen in two patients (12.51%), one patient in each group. Lateralization of the graft was seen in one patient in the transmastoid group, and no ossicular chain refixation. Five cases had postoperative otorrhea, one in the anterior mastoid group and four in the transmastoid group. There were no other complications. Conclusions Although the findings of the hearing are close. The previous approach, due to fewer postoperative complications, is now our favorite technique. Proper alignment and soft-tissue strategies are keys to the effective correction of the congenitally atretic ear canal.

Anatomic Measurements of Distances from Lateral Surface of Cranium to Cochlea in Congenital Aural Atresia and Stenosis Patients

<b><i>Introduction:</i></b> Studies have shown that higher response levels can be obtained when the bone conduction stimulation position is closer to the cochlea. However, the morphological characteristics of round window niche and posterior tympanum in congenital aural atresia (CAA) and stenosis (CAS) patients were different from the normal. These affected the position of the cochlea at the cranial base. It was still unknown whether the distances from the cranium of CAA and CAS patients to the cochlea were the same as those of normal patients or not. <b><i>Objective:</i></b> To measure distances from various points on the lateral surface of the cranium to the cochlea and the cranium thickness on these points among a CAA group, CAS group and normal control group, which may provide valuable information for the better position of bone conduction stimulation. <b><i>Methods:</i></b> CT images of CAA, CAS patients and these patients’ healthy sides were analyzed. Firstly, the Frankfurt horizontal plane (Pfrkt) was established. Secondly, a model of part of the cranium was three-dimensionally reconstructed. Then, the Pfrkt plane was rotated down 20, 30 and 40° according to the superior margin of the external auditory canal. At every angle, points 25, 30, 35 and 40 mm away from the superior margin of the external auditory canal were marked out on the surface of the model and recorded as P₂₀A, P₃₀A, P₄₀A, P₂₀B, etc. The spatial distances between the cranium and ipsilateral cochlea were defined as lengths of points on the surface of the model to the cochlea apex (CA), cochlear base (CB) and modiolus midpoint (MM), respectively, recorded as P₂₀A/CA, P₂₀A/CB, P₂₀A/MM, P₃₀A/CA, etc. <b><i>Results and Conclusions:</i></b> In all groups, the length of P₂₀D/CA was the shortest compared to P₃₀D/CA and P₄₀D/CA (<i>p</i> &#x3c; 0.05). The P₂₀A/CB and P₂₀A/MM were also the shortest (<i>p</i> &#x3c; 0.05). When the Pfrkt plane was rotated down 30 and 40°, the results were the same as at 20° (<i>p</i> &#x3c; 0.05). However, P₂₀D, P₃₀D and P₄₀D were almost on the mastoid air cells. We suggest that the bone conduction stimulation position is placed closer to the ear, while avoiding the mastoid air cells in the CAA and CAS patients.

Audiological results and subjective benefit of an active transcutaneous bone-conduction device in patients with congenital aural atresia

Purpose To review functional and subjective benefit after implantation of an active transcutaneous bone conduction device (BCD) in patients with congenital microtia with atresia or stenosis of the external auditory canal. Methods Retrospective chart analysis and questionnaire on the subjective impression of hearing ( Speech, Spatial and Qualities of Hearing Scale (SSQ-B) of patients treated between 2012 and 2015. ResultsResults 18 patients (24 ears) with conductive or mixed hearing loss in unilateral (n = 10) or bilateral (n = 8) atresia were implanted with a BCD. No major complications occurred after implantation. Preoperative unaided air conduction pure tone average at 0.5, 1, 2 and 4 kHz (PTA 4 ) was 69.2 ± 11.7 dB, while postoperative aided PTA 4 was 33.4 ± 6.3 dB, resulting in a mean functional hearing gain of 35.9 +/- 15.6 dB. Preoperatively, the mean monosyllabic word recognition score was 22.9 % ± 22.3 %, which increased to 87.1 % +/- 15.1 % in the aided condition. The Oldenburger Sentence Test at S0N0 revealed a decrease in signal-to-noise-ratio from − 0.58 ± 4.40 dB in the unaided to − 5.67 ± 3.21 dB in the postoperative aided condition for all patients investigated. 15 of 18 patients had a subjective benefit showing a positive SSQ-B score (mean 1.7). Conclusion The implantation of an active bone conduction device brings along subjective and functional benefit for patients with conductive or combined hearing loss.

Surgical corridors for congenital aural atresia with otogenic cerebellar abscess and lateral sinus thrombosis

The following is a case report of an adolescent with mental retardation who had congenital aural atresia with contralateral congenital facial palsy. She developed multiple intracranial complications (cerebellar abscess and lateral sinus thrombosis) due to cholesteatoma. We managed her in a multidisciplinary approach. This report discusses case management, emphasising the meticulous intraoperative steps taken in identifying the landmarks and precautions adopted to avoid postoperative facial palsy and other complications.