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

ORL ◽  
2021 ◽  
pp. 1-8
Author(s):  
Youzhou Xie ◽  
Keguang Chen ◽  
Dongming Yin ◽  
Tianyu Zhang ◽  
Peidong Dai
Keyword(s):  
External Auditory Canal ◽  
Lateral Surface ◽  
Bone Conduction ◽  
Morphological Characteristics ◽  
Control Group ◽  
Aural Atresia ◽  
Congenital Aural Atresia ◽  
Superior Margin ◽  
Air Cells ◽  
Mastoid Air Cells

<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 P<sub>20</sub>A, P<sub>30</sub>A, P<sub>40</sub>A, P<sub>20</sub>B, 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 P<sub>20</sub>A/CA, P<sub>20</sub>A/CB, P<sub>20</sub>A/MM, P<sub>30</sub>A/CA, etc. <b><i>Results and Conclusions:</i></b> In all groups, the length of P<sub>20</sub>D/CA was the shortest compared to P<sub>30</sub>D/CA and P<sub>40</sub>D/CA (<i>p</i> &#x3c; 0.05). The P<sub>20</sub>A/CB and P<sub>20</sub>A/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, P<sub>20</sub>D, P<sub>30</sub>D and P<sub>40</sub>D 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.

High-resolution computed tomography evaluation of congenital aural atresia – how useful is this?

2020 ◽  
Vol 134 (7) ◽  
pp. 610-622
Author(s):  
R Gautam ◽  
J Kumar ◽  
G S Pradhan ◽  
J C Passey ◽  
R Meher ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Facial Nerve ◽  
External Auditory Canal ◽  
Test Results ◽  
High Resolution Computed Tomography ◽  
Aural Atresia ◽  
Ear Malformations ◽  
Congenital Aural Atresia ◽  
Bone Abnormalities

AbstractObjectiveTo depict various temporal bone abnormalities on high-resolution computed tomography in congenital aural atresia patients, and correlate these findings with auditory function test results and microtia subgroup.MethodsForty patients (56 ears) with congenital malformation of the auricle and/or external auditory canal were evaluated. Auricles were graded according to Marx's classification, divided into subgroups of minor (grades I and II) and major (III and IV) microtia. Other associated anomalies of the external auditory canal, tympanic cavity, ossicular status, oval and round windows, facial nerve, and inner ear were evaluated.ResultsMinor and major microtia were observed in 53.6 and 46.4 per cent of ears respectively. Mean hearing levels were 62.47 and 62.37 dB respectively (p = 0.98). The malleus was the most commonly dysplastic ossicle (73.3 vs 80.8 per cent of ears respectively, p = 0.53). Facial nerve (mastoid segment) abnormalities were associated (p = 0.04) with microtia subgroup (80 vs 100 per cent in minor vs major subgroups).ConclusionMicrotia grade was not significantly associated with mean hearing levels or other ear malformations, except for external auditory canal and facial nerve (mastoid segment) anomalies. High-resolution computed tomography is essential in congenital aural atresia, before management strategy is decided.

Long-term Outcomes of Clip Coupler Implantation in Patients with Unilateral Congenital Aural Atresia

2020 ◽  
Vol 129 (12) ◽  
pp. 1221-1228
Author(s):  
Chunli Zhao ◽  
Jinsong Yang ◽  
Yujie Liu ◽  
Mengdie Gao ◽  
Peiwei Chen ◽  
...  
Keyword(s):  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Bone Conduction ◽  
Free Field ◽  
Short Term ◽  
Aural Atresia ◽  
Long Term Follow Up ◽  
Congenital Aural Atresia

Objective: To evaluate the long-term safety and efficacy of the Clip coupler attached to the stapes head in patients with unilateral congenital aural atresia (CAA). Methods: This single-center retrospective study included 16 Mandarin-speaking patients who had unilateral microtia accompanied by CAA. All patients were divided into two groups: the short-term follow-up group (n = 9) and the long-term follow-up group (n = 7). The floating mass transducer of the Vibrant Soundbridge (VSB) was positioned in the stapes head by the Clip coupler. The safety of the VSB was investigated by comparing preoperative and postoperative bone-conduction (BC) thresholds as well as by complications. The effectiveness was evaluated by functional gain (FG), word recognition score (WRS), speech reception threshold (SRT) and signal-to-noise ratio (SNR). Results: Pre- and post-operative BC thresholds were no different in all patients. And no complications developed. VSB-aided thresholds in the free-field had improved significantly in both short- and long-term follow-up groups. The improvements of WRS were observed in two groups. The monosyllabic VSB-aided WRS in the long-term follow-up group was significantly higher than that in the short-term follow-up group. When speech was from the impaired ear and noise presented to the side of normal ear (SVSBNCL), lower SNRs were found in two groups after VSB implantation. However, there was no statistical difference in aided SNR between the two groups at SVSBNCL status. Conclusions: Our results show that the FMT connected to the stapes head is a secure and useful device for patients with unilateral CHL/MHL, not only in terms of improved hearing thresholds, but also improved speech intelligibility in quiet and noisy environments.

External auditory canal duplication anomalies associated with congenital aural atresia

2003 ◽  
Vol 117 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Nikolas H. Blevins ◽  
Seema V. Byahatti ◽  
Collin S. Karmody
Keyword(s):  
Broad Spectrum ◽  
External Auditory Canal ◽  
The Other ◽  
Treacher Collins Syndrome ◽  
External Ear ◽  
Full Spectrum ◽  
Aural Atresia ◽  
Branchial Cleft Anomalies ◽  
Branchial Cleft ◽  
Congenital Aural Atresia

Maldevelopment of the first branchial cleft can produce a broad spectrum of anomalies in its derivative structure, the external auditory canal (EAC). Failure of the cleft to develop normally can result in either the absence of a normally patent EAC (atresia, or stenosis) or a duplication anomaly (cyst, sinus, or fistula). Despite their common origins, the coexistence of these anatomical abnormalities is quite unusual. We present four patients with both aural atresia and duplication anomalies of the EAC. Three patients had non-syndromic unilateral aural atresia and presented with periauricular lesions originating from the first branchial cleft. The other patient had a variant of Treacher Collins syndrome and presented with draining infra-auricular fistulae.The classification and management of first branchial cleft anomalies is reviewed in light of these cases. An understanding of the embryogenesis of the external ear is necessary to successfully recognize and treat this spectrum of deformities. A classification system is presented that encompasses the full spectrum of first cleft anomalies.

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