Do Filling Defects of the Vestibule Represent a Neuroradiological Marker for Congenital Cytomegalovirus? A Retrospective Case Series.

INTRODUCTION: The aim of this study was to investigate whether radiological marker(s) of the inner ear can be detected in congenital cytomegalovirus (cCMV) patients with severe-profound sensorineural hearing loss. METHODS: A retrospective imaging review of confirmed cCMV paediatric patients that had undergone consecutive cochlear implantation was performed at a tertiary hospital. Available pre- and postoperative imaging was examined, and abnormalities of the labyrinth were catalogued by a consultant neuroradiologist in the study group and control group. RESULTS: Twenty-eight paediatric patients with cCMV having undergone cochlear implantation were identified between the ages of 1-15 years (mean 4.7 years) at the time of implantation. Increased density of the vestibule on computed tomography (CT) or filling defects of the vestibule on magnetic resonance imaging (MRI) were identified in 11 and 4 patients, respectively, of the 24 in the case series. No filling defects were identified in any of the 48 CT and MRI control group. CONCLUSION: This study demonstrates a potential novel radiological finding of the inner ear of patients with cCMV. With more research, greater onus placed on MRI and CT for inner ear assessment may facilitate early detection and treatment for patients at risk of significant hearing loss. Further prospective studies in this area will help to validate radiological markers in order to establish a comprehensive inner ear classification system for neuroradiological features in cCMV.

Mutations and altered expression of SERPINF1 in patients with familial otosclerosis.

Otosclerosis is a relatively common heterogenous condition, characterized by abnormal bone remodelling in the otic capsule leading to fixation of the stapedial footplate and an associated conductive hearing loss. Although familial linkage and candidate gene association studies have been performed in recent years, little progress has been made in identifying disease-causing genes. Here, we used whole-exome sequencing in four families exhibiting dominantly inherited otosclerosis to identify 23 candidate variants (reduced to 9 after segregation analysis) for further investigation in a secondary cohort of 84 familial cases. Multiple mutations were found in the SERPINF1 (Serpin Peptidase Inhibitor, Clade F) gene which encodes PEDF (pigment epithelium-derived factor), a potent inhibitor of angiogenesis and known regulator of bone density. Six rare heterozygous SERPINF1 variants were found in seven patients in our familial otosclerosis cohort; three are missense mutations predicted to be deleterious to protein function. The other three variants are all located in the 5'-untranslated region (UTR) of an alternative spliced transcript SERPINF1-012 RNA-seq analysis demonstrated that this is the major SERPINF1 transcript in human stapes bone. Analysis of stapes from two patients with the 5'-UTR mutations showed that they had reduced expression of SERPINF1-012 All three 5'-UTR mutations are predicted to occur within transcription factor binding sites and reporter gene assays confirmed that they affect gene expression levels. Furthermore, RT-qPCR analysis of stapes bone cDNA showed that SERPINF1-012 expression is reduced in otosclerosis patients with and without SERPINF1 mutations, suggesting that it may be a common pathogenic pathway in the disease.

Evidence of distinct RELN and TGFB1 genetic associations in familial and non-familial otosclerosis in a British population.

Otosclerosis is a common form of hearing loss which typically presents in young adults. The disease has a familial, monogenic form and a non-familial form with a more complex aetiology. A previous genome wide association study identified evidence that variants within RELN are associated with the condition. Other genes in which an association has been reported include BMP2, COL1A1, FGF2, PPP2R5B and TGFB1. However, follow up studies have often failed to replicate initial positive results. The aim of this study was to establish if an association exists between eight single nucleotide polymorphisms (SNPs) in these six previously implicated genes and otosclerosis in a British case-control cohort (n = 748). Evidence of an association between rs1800472 in TGFB1 and otosclerosis was found (p = 0.034), this association was strongest amongst non-familial cases (p = 0.011). No evidence of an association was detected with variants in COL1A1, FGF2, BMP2, and PPP2R5B. No association between variation in RELN and otosclerosis was observed in the whole cohort. However, a significant association (p = 0.0057) was detected between one RELN SNP (rs39399) and otosclerosis in familial patients. Additionally, we identify expression of one RELN transcript in 51 of 81 human stapes tested, clarifying previous conflicting data as to whether RELN is expressed in the affected tissue. Our findings strengthen the association of TGFB1 (rs1800472) with otosclerosis and support a relationship between RELN and familial otosclerosis only, which may explain previous variable replications.

Cochlear implant outcomes in patients with Meniere's disease: a large case series.

OBJECTIVE: To perform a matched cohort study to assess whether patients with Meniere's Disease (MD) require more intensive auditory rehabilitation following cochlear implantation (CI) and identify factors that may affect outcomes in patients with MD. METHODS: A retrospective case review was performed. MD and control patients were matched for age, biological sex, implant manufacturer and electrode design. Outcomes measured were speech scores, number of visits to audiology department following switch-on, and post-operative active MD. RESULTS: Forty consecutive implanted MD patients were identified between May 1993 and May 2019. Patients with active MD following CI required significantly more visits to the audiology department compared to controls (P < 0.01) and patients who had inactive MD post-operatively (P < 0.01). However, in MD patients, active MD was less likely following CI (P = 0.03). In patients who continued to experience active MD post-operatively, further medical and surgical ablative intervention was required to control ongoing Meniere's attacks. CONCLUSION: We present the largest case series of performance outcomes in CI patients with MD. Although speech outcomes in MD patients are comparable to controls, patients with active MD pre-operatively are more likely to experience variation in CI performance requiring a prolonged period of auditory rehabilitation compared to inactive preoperative MD.

Does bilateral otosclerosis make pre-operative bone conduction more inaccurate?

OBJECTIVES: To assess whether bilateral otosclerosis renders pre-operative bone conduction more inaccurate by increasing the Carhart effect. METHODS: Retrospective review of a database of pre and post-operative audiograms of 745 ears with otosclerosis treated with stapedectomy from 2013 to 2020 in a tertiary centre. MAIN OUTCOME MEASURES: Change in bone conduction after stapedectomy for otosclerosis in: unilateral otosclerosis (U1); bilateral otosclerosis undergoing first side surgery (B1); bilateral otosclerosis undergoing second side surgery (B2). The magnitude of change in bone conduction post-operatively within and between each group. RESULTS: The average difference in pre and post-operative bone conduction was significant within in all groups (T-stat > 2 and P-value <0.05) with the greatest change observed in the U1 group. Analysis of average change in bone conduction between groups did not reach statistical significance (P-value = 0.37). Analysis of change per frequency demonstrated the greatest change in bone conduction post-operatively at 2000 Hz in all groups. The magnitude of change at 2000 Hz was the greatest in the bilateral groups; however, it did not reach statistical significance when compared to the unilateral group (P-value = 0.36). CONCLUSIONS: This is the first study in the literature to assess the accuracy of pre-operative bone conduction in bilateral versus unilateral otosclerosis. There is no evidence that pre-operative bone conduction in bilateral otosclerosis is more inaccurate than in unilateral disease. In order to assess accuracy of pre-operative bone conduction in otosclerosis a reliable method of assessing post-operative bone conduction is required, without assumption of its equivalence to cochlear reserve.

Stapes Surgery for 121 Patients With Mixed Hearing Loss.

This study aims to determine the benefit of stapes surgery for otosclerosis in 121 patients with a mixed hearing loss and a preoperative bone conduction (BC) threshold >30 dB. Average postoperative air conduction (AC) improved from 61.5 dB to 34.3 dB. Average air-bone gap closed from 27.1 dB to 6.1 dB. Bone conduction improved from 34.3 dB to 28.2 dB, with 38% of patients achieving a postoperative AC of <30 dB. Glasgow Benefit Inventory scores showed significantly increased quality of life postoperatively in the 88 patients who responded to follow-up, with an average score of 56. There was a mean reduction in daily hearing aid use postsurgery of 5.48 hours, with 56% of patients who responded to follow-up questionnaire no longer needing to use one. When assessing suitability for stapes surgery, surgeons should consider that preoperative BC thresholds may be a poor indicator of the true cochlear reserve and therefore the potential for improvement in AC thresholds and quality of life.

Hearing Preservation Outcomes With Standard Length Electrodes in Adult Cochlear Implantation and the Uptake of Electroacoustic Stimulation.

BACKGROUND: Cochlear implantation with preservation of residual low-frequency hearing enables patients to utilize acoustic and electrical stimulation. It is widely accepted that preservation of residual low-frequency hearing is beneficial in both background noise and for music appreciation. The extent to which patients may benefit is not fully understood, but the importance of these concepts is reflected in electrode design developments and also refinement of surgical technique. Greater understanding is needed around factors that may affect hearing preservation. This study reports experience in adults using standard length cochlear implant arrays. OBJECTIVE: The study reviews hearing preservation outcomes using the HEARRING GROUP method for factors such as gender, electrode type, insertion depth, laterality, preoperative hearing level, and time between surgery and audiogram. Furthermore, the study reviews rates of electroacoustic stimulation use in those with postoperative functional residual low-frequency hearing. METHODOLOGY: Retrospective case series. INCLUSION CRITERIA: preoperative ≤ 85 dB HL at 250 Hz and aged ≥ 18 years. The hearing preservation percentages were calculated using the HEARRING group formula S=[1 - ((PTApost - PTApre)/(PTAmax - PTApre))*100]%. Preservation of > 75% was considered complete, 25 to 75% partial, and 1 to 25% minimal. Standardized operative technique with facial recess approach, posterior tympanotomy, and minimally traumatic round window insertion was performed for each implant. RESULTS: Fifty-three implantations in 52 patients met the inclusion criteria. The mean age at implantation was 55.5 years. The average time since the last audiogram was 10 months. The mean average total pre and postoperative pure-tone averages were 92.4 dB, 99.2 dB, respectively, using minimum reporting standards for adult cochlear Implant (CI). Thirty percent demonstrated complete hearing preservation, 35.8% partial hearing preservation, and 20.8% minimal hearing preservation. Overall, mean hearing preservation was 52.9%. Sex, age at implantation, insertion depth, lateral versus perimodiolar electrode, and preoperative hearing level did not statistically significantly affect rates of hearing preservation in our study. There was a statistically significant deterioration in hearing preservation outcomes difference at 3 months compared with 12 months postoperatively. Only two patients within our study out of 17 with functional postoperative hearing went on to use electroacoustic stimulation. CONCLUSION: Hearing preservation varies between patients and postoperative outcomes are difficult to predict. This study adds to existing literature in terms of likelihood of hearing preservation following cochlear implantation. In turn, this improves our ability to counsel patients as to the chances of preserving residual low-frequency hearing postoperatively and their ability to use electroacoustic stimulation.

Revision Stapes Surgery: A Novel Technique of Overcoming Erosion of the Long Process of Incus Using Hydroxylapatite Cement and Shape Memory Piston.

BACKGROUND: Stapes surgery is performed to treat hearing loss in patients with otosclerosis. Erosion of the long process of incus can occur postoperatively and requires demanding revision surgery to further improve the hearing. The authors describe a novel method of performing revision stapes surgery where there is erosion of the long process of incus. METHODS: A retrospective case series analysis of a database of revision stapes operations performed by one surgeon between July 2013 and December 2017 at a tertiary center was carried out. 26 cases were identified where there was significant erosion of long process of incus. The ossicular chain in these cases was reconstructed using a novel technique of using cement to fix the piston prosthesis to the incus remnant. The full technique is described herein. The pre- and postoperative audiometric data were analyzed. RESULTS: Mean preoperative air bone gap (ABG) was 29.3 dB and mean postoperative ABG was 9.9 dB. Of the 22 patients with recorded postoperative masked bone conduction thresholds, 16 had ABG closure to < 10 dB (72.7%). CONCLUSION: We have shown highly favorable outcomes using this novel technique in addressing erosion of the long process of incus in revision cases for patients with otosclerosis.

Use of MRI to determine cochlear duct length in patients undergoing cochlear implantation.

OBJECTIVES: It is recognised that CT can be used to determine the cochlear duct length (CDL) when selecting an electrode for cochlear implantation. It is the practice of our institution to routinely use MRI as the sole modality of pre-operative imaging in the assessment of children referred for consideration of cochlear implantation. We therefore wanted to determine whether MRI could be reliably used to determine cochlear duct length. METHODS: An analysis of 40 ears that had undergone MRI and CT of the temporal bones was undertaken. The diameter of the basal turn was independently measured for each ear using the two modalities, and CDL was then calculated. RESULTS: The mean error of measurement was 0.26 mm (range 0-0.8 mm), leading to a difference in calculated CDL of 0.96 mm (range 0-2.92 mm). CDL did not predict full insertion of 28 mm cochlear implant electrodes in 30 ears. CONCLUSIONS: MRI can be used to reliably determine cochlear duct length.

Recurrent cochlear implant associated seroma: A series of five patients.

Introduction: We have observed a small number of patients with cochlear implants who have a tendency to develop recurrent seromas overlying the implant package. Methods: Five patients with a current or previous history of recurrent seromas presenting for review over a three-month period were identified. A retrospective review of their case notes was undertaken. Results: All patients identified were children, with a mean age at first seroma of 5.0 years (range 1.9-10.4 years). The mean interval between implantation and first episode of seroma was 3.1 years (range 0.9-6.4 years). With the exception of imaging showing a fluid-density collection, investigations were generally unremarkable. Fluid aspirated from one patient was cultured and no organisms were grown. Antibiotics, most commonly amoxicillin / clavulanic acid, were commonly but not universally prescribed. Conclusions: Recurrent cochlear implant associated seroma appears to be an idiopathic process. Investigations are generally unhelpful, and whilst it is probably prudent to treat with antibiotics during an initial presentation, once a pattern of recurrent seroma is established, patients can be treated conservatively.

Stapes Surgery for Profound Hearing Loss Secondary to Otosclerosis.

The objective of this study is to evaluate stapes surgery in patients with otosclerosis and "profound" hearing loss. This means they meet hearing threshold criteria for cochlear implantation (CI). We performed a retrospective study and patient questionnaire. The results from 33 patients (35 ears) were recorded (mean age: 63.6, range: 40-85). The primary outcome measure was hearing thresholds recorded before and after surgery at 0.5, 1, 2, 3, and 4 kHz. Hearing thresholds at 2 and 4 kHz were also analyzed. Glasgow Benefit Inventory (GBI) was used in 21 patients to assess life quality changes. Hearing thresholds improved in 80% of ears (mean improvement, 26.3 dB), were unchanged in 11.4%, and worsened in 8.6%. Mean GBI score was +20.7. Hearing aid use decreased in 23.8% and ceased in 28.6%. One patient subsequently underwent CI. For patients with profound otosclerosis, stapes surgery provides a quantitative improvement in hearing thresholds and improvement in quality of life, with reduced reliance on hearing aids. This avoids CI, auditory rehabilitation, and a change in quality and tonality of sound.

The Epidemiology of Otosclerosis in a British Cohort.

OBJECTIVE: To analyse the epidemiology of otosclerosis in a British cohort collected between 2011 and 2017. DESIGN: Retrospective cohort study. SETTING: Five UK ENT Departments. PATIENTS: Patients with surgically confirmed otosclerosis. MAIN OUTCOME MEASURES: Questionnaire data documented family history of otosclerosis, age of onset, medical history, and information on associated risk factors for 657 patients. Pre and post-surgical pure-tone audiometry was collected for 154 of these patients. RESULTS: The age of onset, incidence of bilateral disease, tinnitus and vertigo, a higher prevalence of women (65%) than men (35%) are similar to those reported previously for otosclerosis cohorts. No association with measles infection was detected. Patients with a family history (40%) have an earlier age of onset and a higher incidence of bilateral disease and vertigo than non-familial subjects. Pedigree analysis is consistent with an autosomal dominant inheritance with reduced penetrance being apparent in 44/91 pedigrees studied. Women who associate their hearing loss with pregnancy have an earlier age of onset than those that do not (p = 6 × 10). CONCLUSIONS: This study confirms that otosclerosis is an early adult onset disease that is more prevalent in women than men with a large minority of patients having a family history of otosclerosis. We report new evidence to support a relationship between pregnancy and otosclerosis progression in a proportion of women. In addition, this is the first study to identify differences in severity between familial and non-familial cases of otosclerosis, highlighting the possibility that more than one etiology may be involved.

Stapes surgery in patients with a small air-bone gap.

The objective of this study was to determine hearing outcomes in patients undergoing stapes surgery with a preoperative air-bone gap (ABG) <21.25 dB. Patients with a unilateral or bilateral preoperative ABG <21.25 dB undergoing primary stapes surgery were identified from a database of all stapes surgeries performed in a tertiary center over 15 years. A total of 254 ears met the inclusion criteria. The primary outcome measure was the degree of closure of the preoperative ABG. A secondary outcome measure was improvement in bone-conduction thresholds at 4 kHz. All patients underwent stapes surgery under local anesthesia. Ossicular reconstruction was achieved using a SMart 360 nitinol fluoroplastic piston (Gyrus ACMI, Inc.; Southborough, Mass.), and complete posterior crurotomy was performed with a KTP laser. Hearing was assessed with clinical voice testing immediately postoperatively and with pure-tone audiometry at 6 weeks postoperatively. A total of 248 ears (97.6%) demonstrated ABG closure to <10 dB. Bone-conduction thresholds showed an increase in 114 (44.9%), no change 74 (29.1%), and a decrease in 66 (26.0%). There is a slight increase in the risk of stapes mobilization in ears with a small ABG when compared to those with larger ABGs; however, this can be overcome by using a laser-assisted technique in combination with good surgical experience. The benefit in terms of hearing aid avoidance and the restoration of symmetrical hearing is both achievable and significant for the patient.

Changes to Hearing Levels Over the First Year After Stapes Surgery: An Analysis of 139 Patients.

BACKGROUND: Stapes surgery is performed for hearing restoration in patients with otosclerosis. Results from stapes surgery are good, although a small proportion will have a persistent conductive hearing loss and will consider revision surgery. The timing of such surgery depends on expected changes to hearing thresholds during the postoperative period. METHODS: We performed a retrospective case series analysis of a database of outcomes from stapes surgery performed between July 26, 2013 and March 11, 2016 at one center. Hearing outcomes over the year subsequent to surgery were recorded. RESULTS: There was a significant improvement in hearing outcomes between the postoperative visit at 6 weeks (mean air-bone gap 6.0 dB) and the hearing outcome at 6 months (mean air-bone gap 3.3 dB) (p < 0.01). This improvement was maintained at 12 months (mean air-bone gap 3.1 dB), although there were individual patients whose hearing outcome improved or deteriorated during this period. Improvements in air conduction thresholds mirrored improvements in air-bone gap measurements. CONCLUSION: Patients with an initial suboptimal or poor result after stapes surgery may observed improvement in their hearing thresholds in the year after surgery. These patients may have large preoperative air-bone gaps, and have a trend to have obliterated footplates. Revision surgery should not be considered until at least 6 months after primary surgery.

Evaluating inter-aural hearing preservation in bilateral paediatric cochlear implantation.

OBJECTIVE: To examine inter-aural hearing preservation results in children undergoing simultaneous bilateral cochlear implantation (CI). METHODS: Retrospective case review in tertiary referral centre. All children undergoing simultaneous bilateral CI between January 2013 and June 2014 (18 months). Patients eligible for inclusion in the study had pre-operative hearing thresholds of <90 dB at 250 Hz and ≥100 dB at 500 Hz. Patients with anatomical cochlear anomalies or missing data were excluded. Seven patients were included, 1 male, 6 female, mean age of 12 years 11 months at the time of surgery. All patients had simultaneous bilateral cochlear implant surgery, using the same implant and technique. All patients had pre- and post-operative unaided pure tone audiometry. Inter-aural hearing preservation results were compared in each patient. RESULTS: The achieved hearing preservation for 14 ears was complete in 5, partial in 7, and minimal in 2. Measurable hearing preservation was achieved in 86% overall. Inter-aural analysis revealed that only 2 (subjects 1 and 4) of the 7 patients had preservation results within the same preservation group (complete/partial/minimal). The mean inter-aural preservation difference was 30.7% with a range from 12.4% to 65.2%. CONCLUSIONS: Several factors and techniques have already been identified in the wider literature to explain differences in hearing preservation results in CI. However, despite controlling for known factors, we demonstrate variable inter-aural results. This suggests that there may be more factors beyond the surgeon's control influencing our ability to provide consistent results.

Hearing Preservation With Standard Length Electrodes in Pediatric Cochlear Implantation.

OBJECTIVE: Preserving low frequencies following cochlear implantation improves outcomes and allows patients to use a combination of electrical and acoustic stimulation. This importance has been reflected in advances in electrode design and refined surgical techniques. Full insertion of standard length electrodes may be advantageous over shortened electrodes because more electrodes can be activated over time if low frequency hearing loss progresses. Surgeons must counsel patients over this choice but data is lacking regarding the degree and likelihood of hearing preservation achievable with standard length electrodes in children. We report our experience using standard length cochlear implant arrays for hearing preservation in children. METHODS: Retrospective case series. INCLUSION CRITERIA: preoperative hearing ≤85 dB HL at 250 Hz and aged ≤18 years. Hearing preservation percentages are calculated using the HEARRING group formula. (Equation is included in full-text article.)Preservation of > 75% was considered complete, 25 to 75% partial, and 1 to 25% minimal. Patients were implanted with either MED-EL FLEX28 or Cochlear Nucleus CI522. Standardized operative technique with facial recess approach, posterior tympanotomy and minimally traumatic round window insertion. RESULTS: Fifty-two implantations in 27 pediatric patients met inclusion criteria. Mean age at implantation: 9.8 years. Average latest audiogram: 8 months. Mean total pre- and postoperative pure-tone averages were 82.8 and 92.6 dB. Seventeen (33%) ears demonstrated complete hearing preservation, 22 (42%) ears partial hearing preservation, 7 (13%) minimal hearing preservation, and 6 (12%) exhibited no acoustic hearing postoperatively. Mean hearing preservation was 55.5%. CONCLUSION: Hearing preservation is achievable to varying degrees in pediatric cochlear implantation using standard length electrodes though it is difficult to predict preoperatively which children may benefit. This study is among the largest additions to the knowledge base for this patient group.

Taste change following cochlear implantation.

Taste change is a well documented but under emphasised complication of middle ear surgery and is usually related to damage to the chorda tympani nerve (CTN). However, the taste outcomes following cochlear implantation have not been previously recorded. One hundred and forty one patients who had received cochlear implants between January 1997 and April 2006 were questioned using a postal survey regarding changes in the sense of taste following cochlear implantation. Sixty seven per cent of questionnaires were returned. Forty three patients (45%) experienced changes in taste following their surgery. Eighteen patients (19%) said that their symptoms had not resolved by the end of the follow up period (mean 51 months). CTN division produced taste change in 86%. Fifty per cent of patients who had CTN preservation developed taste change, presumably related to occult trauma to the nerve. The difference in the number of patients describing taste change in the two groups was statistically significant (p < 0.05). Resolution of symptoms took a mean of 20 weeks. For those patients in whom taste change was noted, resolution of symptoms was more likely if the CTN was divided rather than preserved although the difference was not statistically significant (p < 0.5). This may reflect neuronal injury during surgery which then fails to heal normally. These results are comparable to taste outcomes in patients undertaking middle ear surgery for non-inflammatory disease such as stapedectomy. The symptoms can be extremely troublesome and may not resolve with time. Careful consideration of the CTN intra-operatively is recommended and in the event of injury, the taste outcome may be better if the nerve is divided rather than left in situ but damaged. These findings have significant implications for patients as bilateral implantation becomes more commonplace.

How I do it/short communication: the middle temporal artery flap for coverage of an exposed cochlear implant cable in the mastoid cavity.

A patient who had previously undergone a modified radical mastoidectomy subsequently underwent cochlear implantation with good results. At surgery the mastoid cavity was partially obliterated to provide soft tissue cover for the implant cables. Following local infection the cable became exposed and we used a middle temporal artery local flap to provide cover for the cable. The anatomy of the flap and methods used are described here. The patient continues to have good hearing from the implant with a good coverage over the cable.

Use and abuse of cotton buds.

Ear injuries caused by cotton buds are commonly seen in ear, nose and throat (ENT) practice. We asked 1000 patients attending an ENT referral clinic whether they used cotton buds to clean the ear canal. Of the 325 who responded, 171 said they did. The frequency of use was no higher in those with ear complaints than in those with nose and other complaints. 15-20% of respondents disagreed with the statements that cotton buds can cause infections, wax impaction or perforations. On the evidence of this survey, manufacturers' warnings need to be fortified.

Heterotopic ossification in chronic fibrosing otitis externa.

Acquired external auditory canal atresia is a rare complication of chronic inflammatory otitis, and is generally fibrous or soft tissue in nature. Here, we present the first reported case of heterotopic ossification within chronic fibrosing otitis externa in a 25-year-old male patient with a childhood history of granular myringitis and failed tympanoplasty. A calcified mass was demonstrated adjacent to the tympanic membrane on CT imaging, and surgical exploration revealed a cohesive bar of bone traversing the medial external auditory canal. Drill canaloplasty and split-thickness skin graft coverage of the lateral tympanic membrane resulted in an improvement in the pure tone average from 79 to 55 dB. As the treatment for chronic fibrosing otitis externa involves the surgical widening of the external auditory canal, we alert surgeons to the possibility of cohesive bone formation as a potential cause of navigational confusion and inadvertent over- or under-drilling of the canal stenosis.