External auditory canal cholesteatoma and keratosis obturans: the role of imaging in preventing facial nerve injury

External Ear Disease: Keratinaceous Lesions of the External Auditory Canal

Keratosis obturans (KO) and external auditory canal cholesteatoma (EACC) are two distinct keratinaceous lesions of the external ear. This article reviews the signs, symptoms, pathophysiology, workup, and treatment of each. Patients with either pathology can often be managed in the clinic with debridement; however, EACC is more likely to involve osteonecrosis and require more extensive operative management if disease is not confined to the canal on account of the bony erosion characteristic of cholesteatoma. If required for extensive disease, surgical approaches to both pathologies are similar.

Taste Alteration in External Auditory Canal Cholesteatoma: Indicator of Impending N VII Affection

INTRODUCTION

External auditory canal cholesteatoma (EACC) is a rare disease, with an estimated incidence of approximately 1:1,000 adult and 1.6:1,000 pediatric otologic patients. Systematic studies of chronic ear disease and taste alteration prior to surgery are rare; in fact, there are no such studies for EACCs. Therefore, we describe chorda tympani nerve (CTN) dysfunction and the related clinical consequences in EACC patients.

METHODS/STUDY DESIGN

Between 1992 and 2021, we retrospectively analyzed the symptoms, signs, and radiological and intraoperative descriptions of CTN involvement in 73 patients. Liquid taste tests and, since 2009, Taste StripsTM as well as an olfactory screening test (Smell DiskettesTM) have been performed for all symptomatic patients and, when feasible, all other EACC patients.

LEVEL OF EVIDENCE: 4

RESULTS

Ten of 73 patients complained subjectively of dysfunction, and 8 showed abnormal taste test results. Four patients complained of olfactory dysfunction (3 cases with pathological taste tests). Gustatory dysfunction was most frequent in radiogenic EACC cases (n = 4), followed by postoperative EACC (n = 3). Two postoperative patients were asymptomatic despite abnormal test results. Rarely, patients with idiopathic (n = 2) and posttraumatic (n = 1) EACC showed acute taste dysfunction that was confirmed in each with abnormal test results.

DISCUSSION/CONCLUSION

CTN dysfunction often developed asymptomatically in chronic ears, except for idiopathic and posttraumatic EACCs under previous healthy middle ear conditions. Taste disturbance is not a cardinal symptom of EACC, but objective testing suggests that up to one out of 10 EACC patients with advanced disease may experience regional gustatory dysfunction prior to surgery. Especially in context of a new and acute presentation, regional taste dysfunction may alert the clinician of potential progressive EACC invasion and danger to the facial nerve.

A Novel Topical Treatment for Keratosis Obturans

OBJECTIVE

To present and evaluate the treatment of keratosis obturans (KO) using miconazole/triamcinolone 0.1% crème gauzes.

STUDY DESIGN

A retrospective clinical capsule report.

PATIENTS

Twelve patients diagnosed with KO between January 2000 and July 2020 visiting our tertiary hospital setting, were retrospectively reviewed.

INTERVENTIONS

Either miconazole/triamcinolone 0.1% crème gauzes or periodic microscopic removal of the keratin plug.

MAIN OUTCOME MEASURES

No evidence of disease during microscopic inspection of the ear canal.

RESULTS

Successful treatment with miconazole/triamcinolone 0.1% gauzes was seen in 4/7 patients (57%) and successful treatment of periodic cleaning of the ear canal was seen in 1/5 patients (20%).

CONCLUSIONS

Topical treatment of KO with miconazole/triamcinolone 0.1% crème gauzes in the ear canal could be considered as a treatment option for patients diagnosed with KO.

External Auditory Canal Stenosis After Traumatic Auricular Amputation

BACKGROUND

The auricles are easily injured or amputated in case of head trauma. Inadequate treatment of the external auditory canal (EAC) after auricular injury is often seen and can lead to significant complications of the EAC.

CASE REPORT

The authors report 4 cases of auricular injury or amputations. In all patients inadequate first treatment led to stenosis of the EAC. Three patients required recanalization of the EAC because of hearing loss and the risk of further complications.

CONCLUSION

Treatment of auricular injury should consist of (pre-emptive) packing of the EAC with antibiotic gauzes followed by thorough examination of the EAC to prevent canal stenosis and subsequent complications.

Clinical Characteristics of Keratosis Obturans and External Auditory Canal Cholesteatoma

Objective

Keratosis obturans (KO) and external auditory canal cholesteatoma (EACC) have been considered separate entities. While the disorders are distinct, they share many overlapping characteristics, making a correct diagnosis difficult. In the present study, we compared their clinical characteristics and radiological features to clarify the diagnostic criteria.

Study Design

Retrospective case series.

Setting

Academic medical center.

Subjects and Methods

The clinical data of 23 cases of EACC and KO were retrospectively reviewed. The following clinical characteristics were compared between the 2 groups: sex, age, onset of symptoms, follow-up period, audiometric results, and imaging findings on temporal bone computed tomography including bilaterality, location, and the presence of extension to adjacent tissue.

Results

The mean age of the EACC group was significantly older than that of the KO group. All of the cases of EACC occurred unilaterally, and bilateral occurrences of KO were observed in 4 of 9 cases. All of the lesions in the KO group were circumferential, and no lesion in the EACC group invaded the superior canal wall. No significant differences in symptoms, such as acute otalgia, otorrhea, and hearing loss, were noted between the 2 groups. The incidence of conductive hearing impairment more than 10 dB was higher in the KO group than in the EACC group.

Conclusion

Thus, KO and EACC are 2 distinct disease entities that share common features in clinical characteristics except for predominant age and bilaterality. Conservative treatment with meticulous cleaning of the lesion was successful in most cases with a long-term follow-up.

Using coronary computerized tomographic images to predict the bulging second genu of the facial nerve in mastoidectomy

The aim of the present study is to determine whether coronary CT images of the temporal bone are useful to predict a bulging second genu of the facial nerve (SGFN) in mastoidectomy by measuring and comparing the heights of the SGFN above the prominence of the lateral semicircular canal (PLSC) in medial-to-lateral dimension on coronary CT images and in mastoidectomy. The relationship between the SGFN and the PLSC in medial-to-lateral dimension, which may have big variability, can be evaluated on the coronary CT images of the temporal bone. The heights of the SGFN above the PLSC in medial-to-lateral dimension were measured on coronary CT images and in mastoidectomy in 184 patients. If the SGFN is above the PLSC in medial-to-lateral dimension, we called the SGFN a bulging SGFN. The data measured on CT images and in surgery were described in histograms and compared. The sensitivity and the specificity in the diagnosis of a bulging SGFN on CT images were calculated by comparison with surgical measurement. Cohen's kappa coefficient was calculated. The heights of the SGFN above the PLSC measured in medial-to-lateral dimension varied from -2.9 to 2.9 mm on coronary CT images and varied from -3.0 to 3.0 mm in surgery. The data measured in surgery showed that the SGFN was above the PLSC in medial-to-lateral dimension in 27.7% (51/184) patients, at least 1 mm above the PLSC in 15.8% (29/184) patients and at least 2 mm above the PLSC in 6.0% (13/184) patients. The sensitivity and the specificity for CT diagnosis of a bulging SGFN were 100% (51/51) and 91.0% (121/133), respectively. Bulging SGFN can be predicted by measuring the height of the SGFN above the PLSC on coronary CT images of the temporal bone.

Tympanomastoidectomy for cholesteatoma among Nigerians

The incidence of cholesteatoma among Nigerians is not well documented, as is the outcome of surgical treatment. A descriptive analysis of prospectively collected data of cases of cholesteatoma managed with tympanomastoidectomy at National Hospital Abuja between September 2005 and April 2012 is presented. Cases were analyzed for age, sex, type of cholesteatoma, intra-operative findings, and post-operative outcome after 6 months of follow up. A total of 28 ears from 25 cases of cholesteatoma had tympanomastoidectomy. Age range was 6-73 years (mean = 34.4, SD = 18.67). There were 13 females and 12 males. Primary acquired cholesteatoma was seen in 18 cases (20 ears), secondary acquired in 5 cases (six ears), and external auditory canal cholesteatoma was seen in 2 cases (two ears). The sites involved in middle ear cholesteatoma was attic, sinus and mesotympanum pars tensa (16/26), attic, sinus, antrum and mastoid cavity (5/26), attic, sinus, mesotympanum and mastoid antrum (4/26), and attic only (3/26).21/25 of cases (24 ears) managed had single stage intact canal wall (ICW) tympanomastoidectomy, while 4/25 (4 ears) had two-stage surgery with canal wall down tympanomastoidectomy in two of these, and revision surgery done within 12 months of first surgeries. 2/25 cases (in the two stage revision group) had postoperative persistent mastoid cutaneous fistula and were treated with post-auricular advancement flap. The commonest cholesteatoma type seen at National Hospital Abuja, Nigeria was primary acquired type, and involved the attic, sinus and mesotympanum pars tensa mainly, and most can be managed by single stage tympanomastoidectomy.