Acquired Stenosis of the External Ear Canal

Acquired stenosis of the external ear canal (ASEEC) is a relatively uncommon condition. Stenosis or narrowing of the external ear canal (EEC) occurs lateral to the tympanic membrane resulting in a skin lined blind canal. Recurrent otorrhea, and conductive hearing loss are typical clinical features. Although ASEEC can be due to different etiologies, a common pathogenesis, namely an inflammatory cascade, has been implicated. Clinical evaluation, audiogram, and Computed tomography (CT scan) form the mainstay of diagnosis. Surgery is the primary modality for treatment. Restenosis is the most common postsurgical complication.

Postinflammatory Medial Meatal Fibrosis: Histopathologic Features and Outcomes of Surgical Management

OBJECTIVES

The aims of our study were to investigate the clinical and audiometric outcome of the surgical treatment of postinflammatory medial meatal fibrosis (PIMMF) and to review the histopathologic changes in the specimens of the fibrotic plug, in order to try to shed light on the pathogenesis of the disease.

MATERIALS AND METHODS

The clinical records and the histopathologic specimens of all patients who underwent tympanomeatoplasty for PIMMF at the ENT Clinic of the University of Erlangen between 2006 and 2020 were evaluated retrospectively.

RESULTS

Thirty-four patients (41 primary surgical procedures) made up our study cohort. Of this, 28 cases were managed by means of meatoplasty and 13 cases with tympanomeatoplasty. The mean preoperative air-bone gap (ABG) was 27.8 dB (10-44 dB). Postoperative ABG was significantly improved compared to preoperative values at both short- and long-term follow-ups (P < .001 for both). No significant difference was noted between short-term and long-term ABG (P = .240). An ABG ≤20 dB was achieved in 65.8% of patients (short term) and 50% (long term). The overall rate of revision surgery for restenosis was 29.3% (12/41). Histopathologic reevaluation of the fibrotic plugs revealed a mosaic of patterns with frequent occurrence of secondary cholesteatoma-like lesions and keloid-like tissue changes. Lichenoid submucosal inflammation and increased ectopic ceruminous gland lobules were seen less frequently.

DISCUSSION

The moderate long-term outcome of surgical management and the identification of histologic changes with therapeutic implications might pave the way for alternative nonsurgical treatment options.

Risk of Acquired Cholesteatoma and External Auditory Canal Stenosis in Traumatic Brain Injury: A Nationwide Population-Based Cohort Study

The aim of study is to investigate the risk of developing acquired cholesteatoma and external auditory canal (EAC) stenosis after traumatic brain injury (TBI) from the Taiwan National Health Insurance Research Database (NHIRD). Each subject was individually traced from their index date to identify those who received a diagnosis of acquired cholesteatoma and EAC stenosis. Cox regression analyses were applied to determine the risk of TBI-related acquired cholesteatoma and EAC stenosis. The follow-up data collected over 10 years were obtained from the TBI and comparison cohorts, of 455,834 and 911,668 patients, respectively. Multivariate analysis demonstrated that TBI significantly increased the risk of cholesteatoma (adjusted hazard ratio (HR), 1.777; 95% confidence interval (CI), 1.494-2.114, p < 0.001) and EAC stenosis (adjusted (HR), 3.549; 95% (CI), 2.713-4.644, p < 0.001). In our subgroup injury analysis, falls had the highest associated risk (4.308 times), followed by traffic injuries (66.73%; 3.718 times that of the control group). Otolaryngologists should not neglect the clinical importance and carefully investigate the possibility of subsequent cholesteatoma and EAC stenosis, which leads to hearing impairment in patients with TBI. Our research also shows the important role in preventing TBI, especially as a result of traffic injuries and falls.

Transplantation of autologous oral mucosal epithelial cell sheets inhibits the development of acquired external auditory canal atresia in a rabbit model

Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, hearing loss and chronic otorrhea. Although the disease can be treated surgically, the recurrence rate is high. This study explored whether autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. We succeeded in generating a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Endoscopic and histological findings in this model indicated that atresia developed over a 4-week period and was not inhibited by the placement of polyglycolic acid sheets immediately after skin dissection. By contrast, transplantation of autologous oral mucosal epithelial cell sheets, which had been fabricated by culture on temperature-responsive inserts without a feeder layer, prevented the development of atresia during the 4-week period after skin dissection. Transplantation of autologous epithelial cell sheets after surgical treatment of acquired external auditory canal atresia could be a promising new method to reduce the risk of disease recurrence. STATEMENT OF SIGNIFICANCE: Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, which leads to hearing loss and chronic otorrhea. Although surgical treatments are available, the recurrence rate is high. In this study, we successfully generated a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Furthermore, we utilized this new animal model to investigate whether the transplantation of autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. Our results raise the possibility that the transplantation of autologous epithelial cell sheets after surgical treatment of ear canal atresia could be a promising new method to reduce the risk of disease recurrence.

Hearing Results of Surgery for Acquired Atresia of the External Auditory Canal

OBJECTIVE

To evaluate short- and long-term hearing results of surgery for acquired atresia of the external auditory canal (EAC) in a large patient cohort and to define preoperative audiometric conditions useful for patient counseling.

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic tertiary referral center.

PATIENTS

Seventy-eight ears from 72 patients with postinflammatory acquired atresia of the EAC who underwent canal- and meatoplasty were included. Patients with involvement of the ossicular chain, (syndromic) external ear malformations, or congenital aural atresia were excluded.

INTERVENTION

Canal- and meatoplasty.

MAIN OUTCOME MEASURES

Mean pure-tone averages of thresholds at 0.5, 1, 2, and 3 kHz (PTA0.5,1,2,3) for air conduction (AC), bone conduction, and air-bone gap (ABG) were calculated preoperatively and at short-term (≤0.55 yr) and long-term follow-up (>0.55 yr). Additionally, the numbers of ears with a closed ABG ≤10 dB and ≤20 dB, and with Social hearing (defined as: AC PTA0.5,1,2,3 ≤35 dB) were assessed.

RESULTS

At short-term follow-up AC PTA0.5,1,2,3 improved by 18 dB. Social hearing was obtained in 81% of the ears. Postoperatively, 35% of the ears had a closed ABG ≤10 dB, 83% was closed ≤20 dB. During follow-up, significant deterioration of 5 to 7 dB occurred for AC thresholds at 0.25, 0.5, and 1 kHz.

CONCLUSIONS

Surgery for acquired atresia of the EAC is often beneficial. This study suggests overall advantageous surgery when the preoperative indication criteria ABG PTA0.5,1,2,3 >20 dB and AC PTA0.5,1,2,3 >35 dB are applied.

Advancing Cholesteatoma Secondary to Acquired Atresia of the External Auditory Canal: Clinical Perspectives

Acquired atresia of External Auditory Canal (EAC) is seldom encountered in routine otolaryngology practice. Apart from resulting in moderate-to-severe conductive hearing impairment, it is a potentially dreaded condition which might lead to canal cholesteatoma. Suspected to develop as a consequence of a pre-existing chronic otitis externa/media, the EAC atresia leads to proximal (medial) accumulation of desquamated epithelium and denatured keratin (the canal cholesteatoma) that further leads to aggravation of the chronic otitis, thereby initiating a vicious cycle. The canal cholesteatoma might progress unhindered into the middle ear and mastoid cavity, with its characteristic bone-eroding property, producing complications. A high index of clinical suspicion along with proper imaging are therefore essential to apprehend the disease progression in a patient presenting with an apparently innocuous EAC stenosis/atresia. In this report, we illustrate the clinical details of a young girl with unilateral acquired EAC atresia where canal cholesteatoma had turned extensive, invaded the middle ear cleft, and produced a post-aural fistula, thereby establishing one of the extreme outcomes of chronic otitis.

[Acquired atresia and stenosis of the external acoustic meatus]

Acquired atresia of the external acoustic meatus is a rare pathological condition characterized by obliteration of the medial part of the external acoustic canal by a soft fibrous plug. The present article presents an overview of a series of cases of acquired atresia and stenosis of the external acoustic meatus with the description of etiology, pathogenesis, and methods for the treatment of this condition. In the majority of the cases, atresia develops at the final stage of granulation external otitis with or without an accompanying dermatological pathology. Another common cause of the acquired atresia of the external acoustic meatus is the fracture of the temporal bone as well as extensive ear surgery, radiation therapy and a neoplasm in the auditory passage. The surgical strategy for the management of the acquired atresia and stenosis of the external acoustic meatus consists, besides the excision of the fibrous plug, of the application of the cutaneous flaps and/or transplants to cover the bare parts of the bone portion of the affected external canal. In spite of such treatment, the state of the external acoustic canal remains unstable, and a relapse of its atresia and stenosis can not be wholly excluded.

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.

[Surgical treatment results of acquired external auditory canal atresia]

Acquired post inflammatory external auditory canal atresia is a rear complication of external ear disease. It is presented as a connective tissue scar in bony part of external auditory canal. The aim of this study is clinical and epidemiological analysis and presentation of diagnostics and treatment results of patients with atresia treated in the Otolaryngology Department of Medical University of Gdansk.

MATERIAL AND METHODS

In the period of 3 years (2008-11) 10 patients (8 women and 2 men) aged 30 to 70-years-old (medium 53 years) were treated for acquired atresia. All of these patients had medial closure of EAC with thick connective tissue scar and tympanic membrane involvement. Intrameatal access was performed in 5 patients, intraural access in 3 patients and retroaurical access in 2 patients. In all cases canaloplasty with meato-tympanic angle enlargement was performed, skin defect was replaced with free epidermal flap, silicon foil with fibrinous sponge was used for coverage.

RESULTS

In all of our patients external auditory canal widening and hearing improvement was achieved. Due to increasing EAC narrowing four patients underwent second surgery with another free epidermal flap grafting.

CONCLUSION

The selection of surgical access in patients with acquired atresia should comply with the etiology of the disease and the shape of EAC. During surgery we aim at maximal broadening of the bony part of EAC. The success of the treatment depends on meato-tympanic angle enlargement and free epidermal flap grafting.

NON-INVASIVE TECHNIQUE FOR IN VIVO HUMAN EAR CANAL VOLUME MEASUREMENT

This prospective study is to develop a new non-invasive in vivo technique for the measurement of the human external auditory canal (EAC) volume using high resolution computed tomography (HRCT). Eighteen ears of nine male volunteers, with an age range of 20–30, were measured. The EAC volume was measured using three different methods: tympanometry, water injection, and HRCT. Two dimensional image slices of the EAC, in vivo, were obtained from the raw HRCT data. Each 2D CT image slice was composed of 512 × 512 pixels, with a 0.5 mm slice thickness, and a 0.175 × 0.175 × 0.5 mm3 voxel size. HRCT images were processed with Amira® software (Visage Imaging, Inc., San Diego, USA). Three-dimensional images of the EAC were reconstructed using an unconstrained smoothing mode. The resulting volume of the 3D model of the EAC was calculated using a voxel gate stacked tool. Using tympanometry, the mean measured EAC volume, averaged over all ears, was 766.66 mm3 (Standard Deviation, SD = 194.03 mm3). Using water injection, the mean measured EAC volume was 1102.77mm3 (SD = 121.60 mm3). Using HRCT, the mean measured EAC volume was 1082.22 mm3 (SD = 119.63 mm3). As evident from the SD values, variability was greater in the tympanometry group than in the water injection and HRCT groups. This study successfully developed a new technique to measure the EAC volume using HRCT imaging. This non-invasive technique for in vivo EAC volume measurement was less variable than tympanometry, and avoided the intrusive aspect of measurement by water injection. The technique allows effective, non-invasive assessment of the EAC volume pre-canalplasty, providing a predictor of EAC volume post-canalplasty.