The pathophysiology of cholesteatoma

Metagenome Analysis of Cholesteatoma-associated Bacteria: A Pilot Study

Introduction

Cholesteatoma usually harbors a poly-microbial infection. As the diversity of bacterial pathogens in the Indian COM is unknown, we set out to identify the bacteria associated with cholesteatoma disease in different patients of North India using targeted metagenomic analysis of the 16 S rRNA gene.

Methods

We recruited 15 patients of cholesteatomatous chronic otitis media (COM), who underwent surgical disease clearance. We divided these patients into four groups based on the four clinic-radiological stages categorized as per the EAONO/JOS joint consensus statement classification. Representative samples were extracted during the surgery and sent for bacterial culture and sensitivity and 16 S rRNA gene metagenomic analysis.

Results

While 12 (80%) of the patients belonged to clinical Stage I/II; one patient had an extracranial complication (stage III) and two patients had an intracranial complication (stage IV). Our detailed bacterial metagenomics analyses showed that while phylum Proteobacteria was most abundant (reads up to ∼ 95%) in specimens from nine patients, phylum Firmicutes was most abundant (up to ∼ 80%) in specimens from four patients. Gamma (γ) Proteobacteria and Epsilon (ε) Proteobacteria were the most abundant class amongst Proteobacteria. Class Tissierellia stood out as the most abundant Firmicutes (40-60%), followed by Clostridia (20%) and Bacilli (10%). There was negligible difference in the bacterial profiles across all four clinical stages.

Conclusion

Cholesteatoma is primarily associated with Proteobacteria and Firmicutes phyla, even in complicated disease. Further studies with a larger sample size are required to validate our findings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04678-9.

Imaging findings in otitis media and resulting secondary lesions in dogs and cats - an image essay

Over the past 2 decades, the increasing availability of computed tomography (CT) and magnetic resonance imaging (MRI) as well as the growing professional expertise have significantly improved the diagnostics of middle and inner ear diseases in dogs and cats. In answering some of the diagnostic questions, CT and MRT demonstrate equivalent performance. For most questions, however, there are differences in the diagnostic performance due to the physical imaging properties of the 2 modalities.CT is more sensitive in demonstrating involvement of the bulla wall and is more effective for detecting abnormal content within the tympanic bulla. In addition, with CT it is often easier to guide tissue samplings. On the other hand, structural changes of the soft tissues of the skull, head, meninges, brain, and nerves are not or only insufficiently detectable on CT images. MRI is clearly superior here. Therefore, MRI is essential for the characterization of materials inside the bulla cavity and for demonstrating the extent of any central spread of otitis media (OM).In this image essay, CT and MRI features of OM and resulting secondary lesions described in the literature are analyzed and summarized. Own image examples are used for illustration. Information on the etiology, pathogenesis, pathomorphology, and clinical signs important for understanding these changes are presented in concise descriptions.

Exploring trends and developments in cholesteatoma research: a bibliometric analysis

PURPOSE

Examination of the scientific literature on cholesteatoma from past to present using bibliometric methods.

METHODS

A total of 2353 articles on cholesteatoma between 1980 and 2023 were obtained from the Web of Science database and statistically analysed using bibliometric techniques.

RESULTS

The journals with the highest number of contributions to the literature were Otology & Neurotology (n = 192), Acta Oto-Laryngologica (156) and Laryngoscope (149). The most impactful journals based on h-index and total citation (TC) counts were Laryngoscope (h:36, TC: 4241), Otology & Neurotology (29, 3141), and American Journal of Otology (26, 2071) respectively. The most prolific author was Kojima H. (n = 49). According to the findings of the Reference Publication Year Spectroscopy (RPYS) analysis, there has been a significant increase in academic interest in Cholesteatoma since its first description in 1959, particularly following the expansion of its definition in 1977. Subsequently, the trend of increased interest has risen rapidly in later years, with notable peaks in research intensity observed in 1989, 2006, and 2011. The highest academic trend occurred in 2006. In recent years, trending topics have included innovative approaches such as diagnostic and imaging methods particularly alongside technological developments, endoscopic surgery, recurrence and complications, prognosis and quality of life, artificial intelligence, and obliteration.

CONCLUSION

In conclusion, the evolution of cholesteatoma and its research priorities reveal temporal shifts and emerging areas of interest over time. Primarily, diagnosis, treatment, and surgical approaches remain central. Additionally, research has expanded to encompass developments in surgical techniques, imaging modalities, cellular biology, pathology, and molecular mechanisms.

Osteopontin-driven partial epithelial-mesenchymal transition governs the development of middle ear cholesteatoma

Cholesteatoma is a common disease of the middle ear. Currently, surgical removal is the only treatment option and patients face a high risk of relapse. The molecular basis of cholesteatoma remains largely unknown. Here, we show that Osteopontin (OPN), a predominantly secreted protein, plays a crucial role in the development of middle ear cholesteatoma. Global transcriptome analysis revealed the loss of epithelial features and an enhanced immune response in human cholesteatoma tissues. Quantitative RT-PCR and immunohistochemical staining of middle ear cholesteatoma validated the reduced expression of epithelial markers, as well as the elevated expression of mesenchymal markers including Vimentin and Fibronectin, but not N-Cadherin, α-smooth muscle actin (α-SMA) or ferroptosis suppressor protein 1 (FSP1), indicating a partial epithelial-mesenchymal transition (EMT) state. Besides, the expression of OPN was significantly elevated in human cholesteatoma tissues. Treatment with OPN promoted cell proliferation, survival and migration and led to a partial EMT in immortalized human keratinocyte cells. Importantly, blockade of OPN signaling could remarkably improve the cholesteatoma-like symptoms in SD rats. Our mechanistic study demonstrated that the AKT-zinc finger E-box binding homeobox 2 (ZEB2) axis mediated the effects of OPN. Overall, these findings suggest that targeting the OPN signaling represents a promising strategy for the treatment of middle ear cholesteatoma.

Balloon dilation of the eustachian tube using endovascular balloon under local anesthesia-a case series and systematic literature review

Objective

To report a novel technique in Balloon Dilation of Eustachian Tube (BDET) using an endovascular balloon (EVB), in a prospective cohort. The results are compared with reported outcomes using standard balloons.

Methods

Demographic information and clinical parameters were collected prospectively fora series of patients with obstructive eustachian tube dysfunction (OETD). Balloon dilation Eustachian tuboplasty was performed under local anesthesia in a tertiary referral center, using the EVB. Systematic literature review was used for comparison, using Medline via "PubMed", "Embase", and "Web of Science".

Results

Eight OETD candidates (12 ears) were enrolled; 5 males and 3 females. Average age was 48 (range -23 to 63) years. The most common presenting symptom was aural fullness (9/12), followed by ear pressure (7/12), hearing loss (5/12) and tinnitus (4/12). Otoscopically, tympanic membrane retraction was evident in 10/12 ears, the majority of which was class II-Sade classification. Pre-operative tympanogram was type B and C in 7 and 5 ears, respectively. All BDETs were performed without complications. Post-operative tympanometry was A in 8/12 ears. Post-operatively, Eustachian Tube Dysfunction Questionnaire-7 results reduced to within normal limits (average score ≤3) in 11/12 ears (p = 0.0014). The systematic literature review included 6 papers (193 patients, 262 ETs) with comparable results, most also with little adverse effects.

Conclusion

BDET using an EVB is a safe and effective option for OETD. It is well tolerated under local anesthesia in properly selected individuals. The reduced procedural cost may be an important factor in certain healthcare jurisdictions.

Cholesteatoma Severely Impacts the Integrity and Bone Material Quality of the Incus

Cholesteatoma can lead to progressive destruction of the auditory ossicles along with conductive hearing loss but precise data on the microstructural, cellular, and compositional aspects of affected ossicles are not available. Here, we obtained incus specimens from patients who had cholesteatoma with conductive hearing loss. Incudes were evaluated by micro-computed tomography, histomorphometry on undecalcified sections, quantitative backscattered electron imaging, and nanoindentation. Results were compared with two control groups taken from patients with chronic otitis media as well as from skeletally intact donors at autopsy. The porosity of incus specimens was higher in cholesteatoma than in chronic otitis media, along with a higher osteoclast surface per bone surface. Histomorphometric assessment revealed higher osteoid levels and osteocyte numbers in cholesteatoma incudes. Incudes affected by cholesteatoma also showed lower matrix mineralization compared with specimens from healthy controls and chronic otitis media. Furthermore, the modulus-to-hardness ratio was higher in cholesteatoma specimens compared with controls. Taken together, we demonstrated increased porosity along with increased osteoclast indices, impaired matrix mineralization, and altered biomechanical properties as distinct features of the incus in cholesteatoma. Based on our findings, a possible impact of impaired bone quality on conductive hearing loss should be further explored.

Comparative Analysis of the Hearing Effects of Partial Ossicular Replacement Prosthesis Versus Conchal Cartilage in Canal Wall Down Mastoidectomy with Type II Tympanoplasty: A Retrospective Case Review Study

OBJECTIVES

To investigate the effects of titanium partial ossicular replacement prosthesis (PORP) and conchal cartilage for ossiculoplasty on hearing results in single-stage canal wall down (CWD) mastoidectomy surgery with type II tympanoplasty in patients with cholesteatoma.

METHODS

The patients were performed surgeries for the first time by a senior otosurgeon from 2009 to 2022 and were performed CWD mastoidectomy with type II tympanoplasty in one stage were enrolled. Patients who could not be followed up were excluded. Titanium PORP or conchal cartilage was used for ossiculoplasty. When the stapes head was intact, a cartilage 1.2-1.5 mm thick was attached directly to the stapes; when the head of the stapes was eroded, a 1 mm high PORP and cartilage of .2-.5 mm thick were placed on the stapes simultaneously.

RESULTS

148 patients were included in the study in total. The titanium PORP and conchal cartilage groups showed no statistically significant differences at 500, 1000, 2000, and 4000 Hz considering the number of decibels of closure of the air-bone gap (ABG) (P > .05) and pure-tone average ABG (PTA-ABG) (P > .05). Meanwhile, the closure of PTA-ABG between the 2 groups showed no statistically significant differences in the overall distribution (P > .05).

CONCLUSIONS

For patients with cholesteatoma and mobile stapes who underwent CWD mastoidectomy with type II tympanoplasty in one stage, either PORP or conchal cartilage is a satisfactory material for ossiculoplasty.

Micro RNAs and Circular RNAs in Different Forms of Otitis Media

The aim of this comprehensive review was to present the current knowledge on the role of microRNAs (miRNAs) in acute, recurrent, and chronic forms of otitis media. Special attention was focused on cholesteatoma of the middle ear. MicroRNAs modulate gene expression, which, in turn, influences the development and likelihood of the recurrence of acute and aggressive chronic middle ear inflammatory processes. Moreover, this study discusses the modulating role of a specific subgroup of noncoding RNA, circular RNA (circRNA). Recognizing the precise potential pathways and the mechanisms of their function may contribute to a better understanding of the molecular bases of middle ear diseases and identifying novel methods for treating this demanding pathology. Articles published between 2009 and 2022 were used in this analysis. In this review, we provide a complete overview of the latest progress in identifying the role and mechanisms of particular miRNAs and circRNAs in acute, recurrent and chronic forms of otitis media.

Whole exome sequencing study identifies candidate loss of function variants and locus heterogeneity in familial cholesteatoma

Cholesteatoma is a rare progressive disease of the middle ear. Most cases are sporadic, but some patients report a positive family history. Identifying functionally important gene variants associated with this disease has the potential to uncover the molecular basis of cholesteatoma pathology with implications for disease prevention, surveillance, or management. We performed an observational WES study of 21 individuals treated for cholesteatoma who were recruited from ten multiply affected families. These family studies were complemented with gene-level mutational burden analysis. We also applied functional enrichment analyses to identify shared properties and pathways for candidate genes and their products. Filtered data collected from pairs and trios of participants within the ten families revealed 398 rare, loss of function (LOF) variants co-segregating with cholesteatoma in 389 genes. We identified six genes DENND2C, DNAH7, NBEAL1, NEB, PRRC2C, and SHC2, for which we found LOF variants in two or more families. The parallel gene-level analysis of mutation burden identified a significant mutation burden for the genes in the DNAH gene family, which encode products involved in ciliary structure. Functional enrichment analyses identified common pathways for the candidate genes which included GTPase regulator activity, calcium ion binding, and degradation of the extracellular matrix. The number of candidate genes identified and the locus heterogeneity that we describe within and between multiply affected families suggest that the genetic architecture for familial cholesteatoma is complex.

Changes in Coagulation Study and Risk of Developing Cholesteatoma: Is There a Link?

BACKGROUND AND OBJECTIVES

The etiopathogenesis of acquired pediatric cholesteatoma has not yet been fully clarified. Recent studies and modern technologies have led researchers to look for explanations at a molecular level. This study aims to understand if the origins of cholesteatoma could be related to dysfunctions in coagulation factors, thereby emphasizing its role in angiogenesis. Subjects and.

METHODS

This was a retrospective case-control study carried out at a tertiary hospital center between January 2010 and December 2020. The study included 92 children. The variables of the summary coagulation study (partial thromboplastin time, prothrombin time, and international normalized ratio) were compared among children with and without development of chronic otitis media with cholesteatoma.

RESULTS

The cases and controls were comparable in terms of age, type, and number of times that ventilation tubes were placed. Partial thromboplastin times tended to be higher in children who developed cholesteatoma, with a statistically significant difference between the two groups in terms of normal and abnormal partial thromboplastin times (p=0.029).

CONCLUSIONS

The results of this case control study indicate that slight extension of partial thromboplastin times in the coagulation study may not meet the criteria for diagnosis of certain hematological pathologies or clinical significance, but at a molecular level may already have implications for activation of angiogenesis and other growth factors involved in the onset, growth, and expansion of acquired pediatric cholesteatoma.

The Relationship between the M1/M2 Macrophage Polarization and the Degree of Ossicular Erosion in Human Acquired Cholesteatoma: An Immunohistochemical Study

The differential involvement of the macrophage activation phenotypes (M1 vs. M2) has been linked to disease severity in various chronic inflammatory disorders. Pharmacologic manipulation of the M1/M2 macrophage polarization has shown therapeutic potential. Cholesteatoma is a destructive chronic middle ear disease with potentially life-threatening complications. The distribution of macrophage polarization phenotypes in middle ear cholesteatoma has not been described. In the present study, human cholesteatoma specimens acquired during tympanomastoidectomy were retrospectively retrieved and immunohistochemically characterized using a combination of antibodies labeling M1 macrophages (CD80), M2 macrophages (CD163), and total macrophages (CD68). The correlations between the immunohistochemical findings and clinical presentation were assessed. The findings revealed that cholesteatomas with more extensive ossicular erosion demonstrated a significantly higher number of M1 (CD80+) cells and a higher M1/M2 ratio than less invasive cholesteatomas (Wilcoxon test, p < 0.05). The extent of ossicular erosion correlated significantly with the M1/M2 ratio (Spearman correlation coefficient ρ = 0.4, p < 0.05). Thus, the degree of ossicular erosion in human acquired cholesteatoma appears to be related to the M1/M2 macrophage polarization. The investigation of macrophage polarization and functions in various clinical presentations of middle ear cholesteatoma is of great interest since it may contribute to the development of pharmaceutical treatment approaches.

Ears with Cholesteatoma: Outcomes of Canal Wall Up and Down Tympano-Mastoidectomies—A Comparative Prospective Study

This prospective study has been carried out to observe the outcomes of canal wall up (CWU) and canal wall down (CWD) Tympano-mastoidectomies in ears with cholesteatoma. Outcomes of the procedures have been done in terms of recurrence of cholesteatoma, complications, graft uptake rates and post-operative hearing gain. This study was carried out in the Department of Otorhinolaryngology of a reputed tertiary teaching hospital of North India from January 2016 to June 2020, with a mean follow-up of 32 months. The study included 100 patients of otitis media with cholesteatoma. In Canal Wall Up Tympano-mastoidectomy (CWUT) group, the number of males and females were 22 each. On the other hand, 36 males and 20 females underwent Canal Wall Down Tympano-mastoidectomy (CWDT). Each surgery was done as a single-staged and at the end of the surgical procedure angled oto-endoscopes were used for ensuring complete removal of the disease. Though there is no statistically significant difference in recurrence of cholesteatoma and complications rate in CWU and CWD Tympano-mastoidectomy techniques, but CWUT is superior to CWDT in terms of better graft uptake (p = 0.0156), and better average audiological gain (8.56 ± 0.93 dB) with p value = 0.0315. A diligent post-operative follow-up is must for assessing the outcomes of different types of mastoidectomies. This study shows no statistical difference in the disease recurrence and complication rates between Canal Wall Up and Down Tympano-mastoidectomies, though the anatomical changes and creation of the mastoid cavity in canal wall down procedure may affect the graft uptake and post-operative hearing gain. Use of Oto-endoscopes in cholesteatoma surgery helps in improving the outcomes of both techniques and thus recommended if the facility for the same is available.

Downregulation of Calreticulin and Annexin A2 Expression in Acquired Middle Ear Cholesteatoma by 2-DE Analysis

BACKGROUND

Many factors are thought to be associated with the development of cholesteatoma, while the mechanisms of its formation remain unclear. This study aimed to identify the potential mechanisms of the proliferation and growth of cholesteatoma by analysis of the differential expressions of proteins in cholesteatoma and retroauricular skin tissue collected from the same patients.

METHODS

The present study is a retrospective study performed in an academic medical center. Comparative proteomics analyses using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), in addition to immunohistochemical analysis, were conducted to identify differentially-expressed proteins in cholesteatoma tissue as compared with retroauricular skin tissue. Western blotting was also employed to verify the expression patterns of the specific proteins identified by 2-DE and to measure the changes in potential modulators related to cholesteatoma proliferation and growth.

RESULTS

Calreticulin (CRT) and annexin A2 (AnxA2) were identified as being differentially-expressed in cholesteatoma by 2-DE and LC-MS/MS, the results of which were in agreement with the results of immunohistochemical analysis and western blotting. Downregulation of CRT and AnxA2 were observed in cholesteatoma.

CONCLUSION

Our data suggests that CRT and AnxA2 downregulation are seen in cholesteatoma compared to retroauricular skin. We speculate that the reduced expression of CRT and the persistent inflammatory response play important roles in the epithelial proliferation of cholesteatoma.

Immunohistochemical localization of d ‐ β ‐aspartic acid in congenital and acquired middle ear cholesteatoma

Objective/Hypothesis

Middle ear cholesteatoma is characterized by abnormal growth of the keratinizing squamous epithelium of the temporal bone. d‐β‐aspartic acid is the major isomer of d‐aspartic acid found in elderly tissue. We assessed the immunoreactivity to k‐β‐aspartic acid of congenital and acquired middle ear cholesteatomas.

Study Design

Case–control studies.

Material and Methods

Tissue samples were collected from 21 patients comprising 21 ears with congenital middle ear cholesteatoma and 26 patients comprising 29 ears with acquired type. Their clinical and histopathological features were investigated. We divided the middle ear cholesteatoma samples into three layers: the perimatrix, matrix, and cystic contents. The patterns of immunoreactivity to d‐β‐aspartic acid expression were then assessed immunohistochemically.

Results

Two patterns of immunoreactivity to d‐β‐aspartic acid were detected in middle ear cholesteatoma: infiltrative and diffuse. In congenital middle ear cholesteatoma, d‐β‐aspartic acid expression was observed throughout all the layers (perimatrix, matrix, and cystic contents), and immunoreactivity to d‐β‐aspartic acid was dramatically strong in all layers. The expression levels of d‐β‐aspartic acid to the cystic content and perimatrix were significantly higher in congenital middle ear cholesteatoma than in the acquired type.

Conclusions

This study showed the expression levels of d‐β‐aspartic acid in middle ear cholesteatoma to differ significantly between congenital and acquired middle ear cholesteatoma. Our results indicate that overexpression of d‐β‐aspartic acid is likely to be involved in the pathogenesis of cholesteatoma, and we speculate that d‐β‐aspartic acid could be a novel biomarker for, and a therapeutic target in, congenital and acquired middle ear cholesteatoma.

Level of Evidence

4

Congenital cholesteatoma: Clinical features and surgical outcomes

OBJECTIVES

A typical presentation of congenital cholesteatoma (CC) is asymmetric conductive hearing loss (CHL). As CHL is usually associated with middle ear effusion, diagnosis of CC is frequently delayed. This study aimed to describe the clinical characteristics, treatment and outcomes of children with CC.

METHODS

The medical files of children diagnosed with CC at a large tertiary pediatric medical center during 2000-2019 were reviewed. The primary outcome measures were: presenting symptoms, surgical findings, stage of disease, recurrence rate and hearing outcome. Imaging findings and the size of mastoid air cells were assessed in CT scans.

RESULTS

Thirty-nine children were diagnosed with CC. The presenting symptom was unilateral CHL in 85%, with an average speech reception threshold of 41.5 ± 13.7 dB in the affected ear. The mean time from first symptoms to diagnosis was 1.3 years. The surgical approach was exploratory tympanotomy in 25% and canal wall up mastoidectomy in 69%. Seventy percent of the children presented with Potsic stage III-IV. The mean postoperative speech reception threshold was 26.4 ± 12.2 dB (P = 0.002). Recurrence of cholesteatoma occurred in 38% of the patients, mostly in stage III-IV. Mastoid air cell size was significantly smaller on the affected than the unaffected side.

CONCLUSIONS

In children with persistent unilateral or asymmetric conductive hearing loss, CC should be suspected. Late diagnosis of CC is associated with a high recurrence rate. This highlights the need to promote awareness to the disease among primary physicians in the community health care system.

Temporomandibular joint (TMJ) disorders as first clinical manifestations in external auditory canal cholesteatoma. A case report

Introduction and importance

Cholesteatoma is a common occurrence in the middle ear, whereas cholesteatoma of the external auditory canal (EAC) is a rare condition. We report an unusual presentation of the cholesteatoma in the EAC.

Case presentation

We report a case of a 67-year-old male presented to the ENT casualty with a longstanding history of left sided squeaky type sound, aggravated whenever he talks or eats. He subsequently had a Computed Tomography (CT) scan of the left petrous bone which identified a left-sided EAC cholesteatoma. Clinical symptoms of EAC cholesteatoma are non-specific, and hence we recommend considering cholesteatoma when patients present with abnormal EAC symptoms and intact tympanic membrane.

Clinical discussion

His cranial nerves examination was normal, and the tympanic membrane was intact. His blood count and infective marker were normal. The CT scan of the brain showed a lesion in the left external auditory canal close to the tympanic membrane. The lesion was in contact with the anterior inferior canal wall which had features suggesting bony erosion. Gas bubble seen in the posterior part of the TMJ was in relation to bony erosion of the EAC.

Conclusion

The cholesteatoma of the EAC is very rare. CT scan can provide detailed information about the extent of external ear canal cholesteatoma, which can be used to identify complications of the disease, in addition to differentiating the external ear canal from the middle ear cholesteatoma. Early recognition of cholesteatoma and prompt treatment is essential to prevent catastrophic complications.

•

A cholesteatoma originating in the external auditory canal is a rare finding.

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Cholesteatoma can present with atypic symptoms such as temporomandibular joint disorders.

Notch Signaling in Acquired Middle Ear Cholesteatoma

HYPOTHESIS

We hypothesized that an anomalous change of Notch signaling might be involved in the pathophysiology of cholesteatoma.

BACKGROUND

The Notch signaling pathway regulates integrated growth and differentiation control of keratinocytes. Its involvement in cholesteatoma proliferation has not been elucidated.

METHODS

We obtained cholesteatoma and external auditory canal (EAC) skin samples from patients with middle ear cholesteatoma who underwent tympanomastoid surgery. We performed polymerase chain reaction using the RT2 Profiler™ PCR Array Human Notch Signaling Pathway (Qiagen) in the cholesteatoma and EAC skin samples (n = 6 each). This was followed by immunohistochemical staining of Notch1, enhancer of split-1 (HES1), and p53 in 41 and 8 cholesteatoma and EAC skin samples, respectively.

RESULTS

The fold change of Notch1 gene expression was lowest in cholesteatoma, with a statistically significant difference (p = 0.0424). Moreover, the fold change of HES1 expression decreased (p = 0.272). The positive rates of Notch1 and HES1 protein expressions in the cholesteatoma (48.5 ± 32.4% and 44.9 ± 17.8%, respectively) were significantly lower than in the EAC skin (83.4 ± 17.5% and 55.7 ± 7.1%, respectively) (p < 0.001 and p < 0.01). In contrast, the positive rate of p53 expression in the cholesteatoma (8.5 ± 11.4%) was significantly higher than in the EAC skin (0.5 ± 0.7%) (p < 0.001).

CONCLUSION

The decreases in Notch1 and HES1 protein expression might play an important role in the hyperproliferative character of the keratinizing squamous epithelium in cholesteatoma. An increase in p53 might reflect the reaction to cellular hyperproliferation.

The outcomes of endoscopic approach for attic cholesteatoma: underwater continuous drilling versus traditional intermittent drilling

OBJECTIVE

This study aimed to analyse the differences between underwater continuous drilling and traditional intermittent drilling for attic cholesteatoma.

METHODS

The clinical data of 61 patients with attic cholesteatoma who underwent an endoscopic approach procedure were analysed. Forty patients underwent underwater continuous drilling (group A), and 21 patients underwent traditional intermittent drilling (group B).

RESULTS

The operation time was 64.61 ± 12.90 minutes in group A and 79.60 ± 16.81 minutes in group B (p < 0.05). The anaesthesia time was 102.69 ± 17.93 minutes in group A and 119.82 ± 19.28 minutes in group B (p < 0.05). The dry ear time, the hearing improvement rate and the post-operative complications were no different in the two groups.

CONCLUSION

Group A and group B had no differences in surgical outcome or hearing recovery. However, treatment in the former group resulted in a significantly shortened operation and anaesthesia time.

Radiomics of high-resolution computed tomography for the differentiation between cholesteatoma and middle ear inflammation: effects of post-reconstruction methods in a dual-center study

Objectives

To evaluate the performance of radiomic features extracted from high-resolution computed tomography (HRCT) for the differentiation between cholesteatoma and middle ear inflammation (MEI), and to investigate the impact of post-reconstruction harmonization and data resampling.

Methods

One hundred patients were included in this retrospective dual-center study: 48 with histology-proven cholesteatoma (center A: 23; center B: 25) and 52 with MEI (A: 27; B: 25). Radiomic features (co-occurrence and run-length matrix, absolute gradient, autoregressive model, Haar wavelet transform) were extracted from manually defined 2D-ROIs. The ten best features for lesion differentiation were selected using probability of error and average correlation coefficients. A multi-layer perceptron feed-forward artificial neural network (MLP-ANN) was used for radiomics-based classification, with histopathology serving as the reference standard (70% of cases for training, 30% for validation). The analysis was performed five times each on (a) unmodified data and on data that were (b) resampled to the same matrix size, and (c) corrected for acquisition protocol differences using ComBat harmonization.

Results

Using unmodified data, the MLP-ANN classification yielded an overall median area under the receiver operating characteristic curve (AUC) of 0.78 (0.72–0.84). Using original data from center A and resampled data from center B, an overall median AUC of 0.88 (0.82–0.99) was yielded, while using ComBat harmonized data, an overall median AUC of 0.89 (0.79–0.92) was revealed.

Conclusion

Radiomic features extracted from HRCT differentiate between cholesteatoma and MEI. When using multi-centric data obtained with differences in CT acquisition parameters, data resampling and ComBat post-reconstruction harmonization clearly improve radiomics-based lesion classification.

Key Points

• Unenhanced high-resolution CT coupled with radiomics analysis may be useful for the differentiation between cholesteatoma and middle ear inflammation.

• Pooling of data extracted from inhomogeneous CT datasets does not appear meaningful without further post-processing.

• When using multi-centric CT data obtained with differences in acquisition parameters, post-reconstruction harmonization and data resampling clearly improve radiomics-based soft-tissue differentiation.

Endoscopic Management of Primary Acquired Cholesteatoma

Endoscopic ear surgery is increasingly accepted as a primary modality for cholesteatoma surgery. A major advantage is the enhanced visualization of the middle ear in traditionally poorly accessible locations by the microscope. We discuss novel techniques for selective mastoid obliteration when a canal wall down mastoidectomy is necessary. Postoperatively, indications for non-echo planar diffusion-weighted imaging MRI versus second-look surgery are discussed. Finally, outcome data for endoscopic versus microscopic ear surgery are reviewed, which show equivalent outcomes regarding residual and recurrent disease, similar rates of complications, decreased pain, and shorter healing time.

Relationship between clinicopathological characteristics and CYLD expression in patients with cholesteatoma

Middle ear cholesteatoma is a destructive disease in which inflammation plays an important role in development and progression, and there are currently no biomarkers predicting prognosis or recurrence. Cylindromatosis (CYLD), a tumor suppressor deubiquitinase, serves as a negative regulator of inflammation expressed in tissues including the middle ear. To determine the clinical significance of CYLD in acquired cholesteatoma, we evaluated CYLD expression in acquired cholesteatoma tissue by immunostaining and analyzed its correlation with clinicopathological characteristics. Our immunohistochemical analysis revealed that CYLD expression levels were varied in the tissues of acquired cholesteatoma patients. The relative expression levels of CYLD in cholesteatoma exhibited a significant correlation with the grade of otorrhea (R = 0.532, p = 0.039). Moreover, the period of epithelialization was also significantly associated with the relative expression levels of CYLD (R = 0.720, p = 0.002). In addition, CYLD expression tended to be lower in the group with recurrence. These results suggest that low CYLD expression correlates with postoperative recovery of acquired cholesteatoma, while potentially affecting the induction of recurrence. This is the first report showing that low CYLD expression correlates with accelerated disease recovery, and suggests a new aspect of CYLD as a prognostic predictor of acquired cholesteatoma.

Surgical Guidance for Removal of Cholesteatoma Using a Multispectral 3D-Endoscope

We develop a stereo-multispectral endoscopic prototype in which a filter-wheel is used for surgical guidance to remove cholesteatoma tissue in the middle ear. Cholesteatoma is a destructive proliferating tissue. The only treatment for this disease is surgery. Removal is a very demanding task, even for experienced surgeons. It is very difficult to distinguish between bone and cholesteatoma. In addition, it can even reoccur if not all tissue particles of the cholesteatoma are removed, which leads to undesirable follow-up operations. Therefore, we propose an image-based method that combines multispectral tissue classification and 3D reconstruction to identify all parts of the removed tissue and determine their metric dimensions intraoperatively. The designed multispectral filter-wheel 3D-endoscope prototype can switch between narrow-band spectral and broad-band white illumination, which is technically evaluated in terms of optical system properties. Further, it is tested and evaluated on three patients. The wavelengths 400 nm and 420 nm are identified as most suitable for the differentiation task. The stereoscopic image acquisition allows accurate 3D surface reconstruction of the enhanced image information. The first results are promising, as the cholesteatoma can be easily highlighted, correctly identified, and visualized as a true-to-scale 3D model showing the patient-specific anatomy.

The Medially-Invasive Cholesteatoma: An Aggressive Subtype of a Common Pathology

OBJECTIVE

Describe the outcomes of treatment for patients with cholesteatomas that are medially invasive to the otic capsule, petrous apex, and/or skull base.

STUDY DESIGN

Retrospective case series.

SETTING

Two tertiary care academic centers.

PATIENTS

Patients surgically managed for medially-invasive cholesteatoma at two tertiary care institutions from 2001 to 2017.

INTERVENTIONS

Surgical management of medially-invasive cholesteatomas.

MAIN OUTCOME MEASURES

The presenting symptoms, imaging, pre- and post-operative clinical course, and complications were reviewed.

RESULTS

Seven patients were identified. All patients had pre-operative radiographic evidence of invasive cholesteatoma with erosion into the otic capsule beyond just a lateral semicircular canal fistula. Five patients had a complex otologic history with multiple surgeries for recurrent cholesteatoma including three with prior canal wall down mastoidectomy surgeries. Average age at the time of surgery was 41.3 years (range 20-83). Two patients underwent a hearing preservation approach to the skull base while all others underwent a surgical approach based on the extent of the lesion. Facial nerve function was maintained at the pre-operative level in all but one patient. No patient developed cholesteatoma recurrence.

CONCLUSIONS

The medially-invasive cholesteatoma demonstrates an aggressive, endophytic growth pattern, invading into the otic capsule or through the perilabyrinthine air cells to the petrous apex. Surgical resection remains the best treatment option for medially-invasive cholesteatoma. When CSF leak is a concern, a subtotal petrosectomy with closure of the ear is often necessary.

Cholesteatoma Versus Granulations: Changing Incidence Trends and Association with Age and Complications

Purpose

CSOM is a common disease in lower socio-economic set-ups. Its incidence has decreased over time due to improved hygiene status increased use of antibiotics. It can be associated with cholesteatoma or granulation tissue as far as unsafe ears are considered. Cholesteatoma is defined as a well demarcated noncancerous cystic lesion derived from an abnormal growth of keratinising squamous epithelium in the temporal bone, commonly characterised as skin in the wrong place. Granulations are defined as the inflammatory response of middle ear mucosa to toxic insults. Overtime the incidence of granulations has increased. This study aims to observe the incidence trends of cholesteatoma in comparison to granulation tissue as intraoperative finding in CSOM patients and the association of these two with the age of the patient and associated complications if present.

Materials and Methods

All the patients admitted to E.N.T ward of M.D.M. Hospital, Jodhpur, Rajasthan, India undergoing mastoid exploration surgery between the time period of 1 year from September 2017 to August 2018 were observed and their clinical findings along with patients data including age and sex were recorded and studied in regard with incidence of cholesteatoma, granulation tissue or both simultaneously along with associated complications.

Results

Majority of the patients who required mastoid exploration surgery had the presence of granulation tissue as intraoperative finding (55.07%). The incidence of cholesteatoma and both cholesteatoma and granulations together was (21.73%) and (23.18%) respectively. Complication percentage was highest with that of cholesteatoma patients (44.45%). Most of the patients presented in the 3rd-4th decade of their lives (63.77%) and the incidence was low amongst the children (30.43%) and the elderly (5.8%). The complication rate was higher in children (55.56%).

Conclusion

Granulation tissue showed an increased incidence trend as compared with cholesteatoma; although complication rate was higher in the latter. Incidence as a function of age was maximum in the middle ages but the complication rate was more amongst the children.

Association of CARD8 Activating Polymorphism With Bone Erosion in Cholesteatoma Patients

OBJECTIVES

We compared the incidence of polymorphisms activating the NLRP3 inflammasome between controls and patients with cholesteatoma and its potential association with bone erosion in patients with cholesteatoma.

METHODS

This is a case-control study assessing the mutation rates in genes of interest in patients with and without cholesteatoma. A total of 133 saliva samples from control (n = 65) and cholesteatoma (n = 68) patients were collected for DNA extraction. Caspase recruitment domain family member 8 (CARD8) (AA: homozygous wild type, AT: heterozygous, TT: homozygous mutant polymorphism) and NLRP3 (CC: homozygous wild type, CA: heterozygous, AA: homozygous mutant) polymorphisms were analyzed with TaqMan single-nucleotide polymorphism (SNP) quantitative polymerase chain reaction (ThermoFisher Scientific, Waltham, MA). Mutation status was correlated with a novel bone erosion scoring model developed as a part of this study. Summary statistics, including frequencies (%) and median (Q1, Q3) were used to describe the sample.

RESULTS

The presence of CARD8 and NLRP3 homozygous wild-type polymorphisms were generally similar for the control and cholesteatoma patient groups. CARD8 homozygous TT polymorphisms were an exception, occurring more frequently in patients who developed a cholesteatoma compared to the control group (29% vs. 10%, P = .009). Those patients with CARD8 homozygous TT polymorphism had higher median scores of bone erosion as compared to subjects with nonhomozygous mutant genotypes (median [interquartile range]: 4.0 [3.0, 5.5] vs. 2.5 [1.0, 3.5], P = .0142).

CONCLUSION

Cholesteatoma patients have a significant, twofold higher incidence of CARD8 homozygous TT polymorphism. Furthermore, cholesteatoma patients with this homozygous polymorphism had greater bone erosion rates than controls. These findings suggest that genetic mutations may increase host susceptibility to cholesteatomas. Specifically, the CARD8 TT polymorphism may influence the severity of cholesteatoma-induced bone erosion.

LEVEL OF EVIDENCE

3B.

A Comparative Study of Type-I Underlay Tympanoplasty with Temporalis Fascia Graft Alone and with Conchal Cartilage

Tympanoplasty which is the repair of the tympanic membrane using temporalis fascia, has been done worldwide and has stood the test of time. However in cases of reperforation or large/subtotal perforations, we are often left in need of some sturdy material for grafting. To compare the graft uptake and hearing improvement in patients undergoing type I tympanoplasty using temporalis fascia alone and temporalis fascia along with conchal cartilage. The current research is a prospective study of 60 patients with chronic suppurative otitis media (Tubo tympanic type), undergoing type I tympanoplasty, using temporalis fascia alone and temporalis fascia along with conchal cartilage. The graft uptake and hearing improvement was much better using temporalis fascia along with conchal cartilage graft as compared to cartilage alone. The use of temporalis fascia along with conchal cartilage graft is beneficial for patients with chronic suppurative otitis media (tubotympanic type) undergoing type I tympanoplasty than using temporalis fascia alone.

Cost-comparison analysis of diffusion weighted magnetic resonance imaging (DWMRI) versus second look surgery for the detection of residual and recurrent cholesteatoma

Background

Cholesteatoma is a destructive, erosive growth of keratinizing squamous epithelium in the middle ear cleft. Following treatment with a canal wall-up (CWU) tympanomastoidectomy, surveillance of residual and recurrent disease has traditionally been achieved through a second look tympanotomy following the initial procedure. Historically, MRI sequences have been inadequate at differentiating between granulation tissue, inflammation, and cholesteatoma. Recent literature has shown diffusion-weighted magnetic resonance imaging (DWMRI) to be a viable alternative to second look surgery for the detection of residual or recurrent disease. The goal of the present study was to perform a cost analysis of DWIMRI versus second look surgery in the detection of residual or recurrent cholesteatoma following combined approach tympanomastoidectomy.

Methods

A probabilistic decision tree model was generated from a literature review to compare traditional second look surgery with DWMRI. Cost inputs were obtained from the Ontario Case Costing Initiative, the Ontario Health Insurance Plan (OHIP) schedule of benefits. Costs were reported in Canadian dollars and a payer perspective was adopted. A probabilistic sensitivity analysis was performed.

Results

According to the probabilistic sensitivity analysis, mean cost difference of traditional second look tympanotomy versus echo planar imaging (EPI) DWMRI was $180.27CAD, 95%CI [$177.32, $188,32] in favour of second-look tympanotomy. However, mean cost difference of traditional second look tympanotomy versus non-EPI DWMRI was $390.66CAD, 95%CI [$381.52, $399.80] in favour of non-EPI DWMRI.

Conclusions

Diffusion-weighted MRI, specifically non-EPI sequences, are a viable cost-saving alternative to second-look tympanotomy in the setting of detecting residual or recurrent cholesteatoma.

Canal wall down versus canal wall up surgeries in the treatment of middle ear cholesteatoma

Background/aim

To compare outcomes of canal wall up (CWU) and canal wall down (CWD) techniques in the treatment of middle ear cholesteatoma.

Materials and methods

Medical records of 76 patients who had a primary surgery due to middle ear cholesteatoma between July 2015 and November 2017 were reviewed retrospectively. Hearing thresholds, speech discrimination scores (SDS), recurrences, and revision surgeries of CWU and CWD surgeries were compared.

Results

Of 76 cholesteatoma cases, 40 (52.6%) had a CWU and 36 (47.4%) had a CWD operation. Postoperatively, the mean air conduction thresholds were significantly better in CWU compared to CWD surgeries (P = 0.016). The presence of the stapes and the type of reconstruction material used did not have a significant effect on auditory success rates (P = 0.342 and P = 0.905, respectively). Auditory success was affected by the status of the middle ear mucosa as well. The recurrence and revision rates did not differ between the surgical techniques (P > 0.05).

Conclusion

Status of the middle ear mucosa and external auditory canal are important factors affecting the outcomes in cholesteatoma. Instead of a CWD surgery, a CWU surgery seems applicable in cases of cholesteatoma when the bone in the external auditory canal is not eroded by the disease.

The diagnostic accuracy of 1.5 T versus 3 T non-echo-planar diffusion-weighted imaging in the detection of residual or recurrent cholesteatoma in the middle ear and mastoid

PURPOSE AND BACKGROUND

This study retrospectively compares diagnostic performance of 1.5 T versus 3 T non-echo planar diffusion weighted imaging with or without additional T1 and T2 sequences in the detection of residual and/or recurrent cholesteatoma.

METHODS

Patients with clinically suspected recurrent cholesteatoma or postoperative routine survey MR who subsequently underwent surgical procedure were retrospectively included (135 patients, 164 operated ears) from a large database. Patients underwent 1.5 T (128 ears) or 3 T MRI (36 ears), with non-echo planar DWI, T1 and T2 acquisitions. Two radiologists independently reassessed the images. Definitive surgical diagnosis was used as gold standard. Sensitivity, specificity and diagnostic odds ratio were evaluated.

RESULTS

According to surgical diagnosis a cholesteatoma was present in 124 of 164 ears, corresponding with a prevalence of 75%. Sensitivity and specificity were lower for 3 T compared to 1.5 T, irrespective of whether additional T1 and T2-weighted sequences were used or not. Diagnostic odds ratios were higher for 1.5 T (34 and 12 for reader 1 and 2, respectively) compared to 3 T (3 and 4 for reader 1 and 2, respectively). Adding T1 and T2 sequences lowers sensitivity but increases specificity.

CONCLUSION

Non-epi DWI for the detection of residual/recurrent cholesteatoma is preferably performed on 1.5 T scanners over 3 T. The use of additional sequences regarding detection of cholesteatoma is debatable as it lowers sensitivity but increases specificity. However, these sequences may also be of use in diagnosing complications and planning surgical procedures in some hospitals.

Outcomes Following Modified Tympanomastoidectomy With Soft-wall Reconstruction

OBJECTIVE

To report outcomes following modified tympanomastoidectomy with soft-wall reconstruction (MTMSWR).

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary referral center.

PATIENTS

Forty-seven patients (48 ears) with aggressive cholesteatoma undergoing MTMSWR.

INTERVENTIONS

Canal wall down (CWD) tympanomastoidectomy with temporalis fascia reconstruction of the posterior external auditory canal (EAC).

MAIN OUTCOME MEASURES

Cholesteatoma recidivism; hearing outcomes; degree of soft-wall retraction; time to epithelialization; otorrhea.

RESULTS

All ears had some form of ossicular compromise. There were 41 ears with completed surveillance of which 39% demonstrated recidivism for cholesteatoma. Of these, 68.8% had a small cholesteatoma foci averaging 3.7 mm. Air pure-tone average remained stable or improved for 60.0% and declined ≤ 20 dB for 85.7%. Excluding ears unable to undergo ossicular chain reconstruction, final air-bone gap was ≤ 30 dB for 66.7%. Retraction of the reconstructed wall was absent-to-mild in 34.7% and moderate-to-full in 52.1%. Thirteen percent had soft-wall breakdown. Average time to full epithelialization of the wall was 58.5 days.

CONCLUSIONS

MTMSWR is an option for restoring the posterior EAC wall following CWD surgery. Recidivism is comparable to canal wall up surgery, and hearing outcomes are generally better than CWD. Other advantages include rapid epithelialization, low rates of otorrhea, and restoration of a self-cleaning EAC regardless of retraction into the mastoid cavity.

[Is routine histopathologic examination of middle ear cholesteatoma necessary?]

BACKGROUND

In the course of restoration of the middle ear, routine histological examinations are initiated in many cases, although a middle ear cholesteatoma can be clinically diagnosed in a normal case.

AIM OF THE STUDY

To determine the correlation between the surgeons' diagnosis and that of the pathologist and comparison with literature data. To check the rate of unexpected diagnoses. Analysis of the costs and survey of German ENT clinics with regard to handling of the histological examination in suspected cholesteatoma.

MATERIALS AND METHODS

Retrospective evaluation of cholesteatoma cases of the ENT Department of the University Medical Center of Mainz from 2010-2015. Germany-wide postal survey of ENT clinics.

RESULTS

In all, 449 operations for the rehabilitation of a middle ear cholesteatoma, of which there were 312 (69.5%) first diagnoses and 137 (30.5%) recurrences. A histological examination was conducted in 78.6%. For first diagnoses, the sensitivity of the clinical assessment was 97.9%, specificity 10%, positive predictive value 96.3%, and negative predictive value 16.7%. Recurrences showed values of 100%, 40%, 97.1% and 100%. Unexpected malignant findings did not occur. This routine histological examination was performed by 58.6% of German ENT hospitals. A total of 80% of those questioned this to be useful. A histological examination cost an average of 14.06 €.

CONCLUSION

Intraoperatively, there is a high degree of accuracy in diagnosing cholesteatoma. The cost factor of the histological examination is low and should not be the basis for the decision. The ear microscopy and the experience of the ear surgeon should be decisive for the decision for histological examination.

Bilateral tympanokeratomas (cholesteatomas) with bilateral otitis media, unilateral otitis interna and acoustic neuritis in a dog

Background

An aural cholesteatoma, more appropriately named tympanokeratoma, is an epidermoid cyst of the middle ear described in several species, including dogs, humans and Mongolian gerbils. The cyst lining consists of stratified, keratinizing squamous epithelium with central accumulation of a keratin debris. This case report describes vestibular ganglioneuritis and perineuritis in a dog with chronic otitis, bilateral tympanokeratomas and presumed extension of otic infection to the central nervous system.

Case presentation

An 11-year-old intact male Dalmatian dog with chronic bilateral otitis externa and sudden development of symptoms of vestibular disease was examined. Due to the dog’s old age the owner opted for euthanasia without any further examination or treatment and the dog was submitted for necropsy. Transection of the ears revealed grey soft material in the external ear canals and pearly white, dry material consistent with keratin in the tympanic bullae bilaterally. The brain and meninges were grossly unremarkable. Microscopical findings included bilateral otitis externa and media, unilateral otitis interna, ganglioneuritis and perineuritis of the spiral ganglion of the vestibulocochlear nerve and multifocal to coalescing, purulent meningitis. A keratinizing squamous epithelial layer continuous with the external acoustic meatus lined the middle ear compartments, consistent with bilateral tympanokeratomas. Focal bony erosion of the petrous portion of the temporal bone and squamous epithelium and Gram-positive bacterial cocci were evident in the left cochlea. The findings suggest that meningitis developed secondary to erosion of the temporal bone and ganglioneuritis and/or perineuritis of the vestibulocochlear nerve.

Conclusions

Middle ear tympanokeratoma is an important and potentially life-threatening otic condition in the dog. Once a tympanokeratoma has developed expansion of the cyst can lead to erosion of bone and extension of otic infection to the inner ear, vestibulocochlear ganglion and nerve potentially leading to bacterial infection of the central nervous system.

Electronic supplementary material

The online version of this article (10.1186/s13028-018-0386-4) contains supplementary material, which is available to authorized users.

Shewanella algae in a chronic suppurative otitis media patient with cholesteatoma

We present Shewanella algea infection in a chronic suppurative otitis media (CSOM) patient with cholesteatoma in terms of clinical course and treatment. This is the first time S. algea is found as solely pathogen in a CSOM patient without history of contact with seawater in Turkey. The patient admitted to the hospital several times with complaints of otorrhoea, was diagnosed as otitis media and treated. He was hospitalized to the otorhinolaryngology department for further evaluation of recurrent infections. The patient was diagnosed as cholesteatoma according to computed tomography scan findings and was operated for cholesteatoma. As a result of surgical and medical treatment he was discharged with full recovery. Physicians must be aware of rarely seen pathogens and their unexpected ways of transmission and underlying causes such as cholesteatoma when treating patients for CSOM.

Piezosurgery-, neuroendoscopy-, and neuronavigation-assisted intracranial approach for removal of a recurrent petrous apex cholesteatoma: technical note

Current approaches for resection of petrous bone cholesteatomas (PBCs), such as canal wall up (closed) and canal wall down (open) mastoidectomies, in the pediatric population present recurrence rates ranging between 17% and 70% with a high rate of postoperative complications involving hearing loss and facial nerve weakness. This technical note illustrates an alternative intracranial approach that was used in combination with the techniques of piezoelectric surgery, neuroendoscopy, and neuronavigation for safe and effective removal in a difficult pediatric case of recurrent PBC. The third recurrence of a PBC in a 14-year-old girl was diagnosed by CT and MRI. A retrosigmoid approach gave access to the petrous apex, allowing for the safe and complete removal of the lesion and decompression of the facial nerve and internal carotid artery. The intraoperative implementation of piezoelectric surgery, neuronavigation, neuroendoscopy, and neuromonitoring ensured better intraoperative visualization, safer bone removal, and preservation of nerve function, facilitating a macroscopically total resection of the pathology without additional neurological damage of the adjacent tissues. Cholesteatoma extension could be clearly verified by intraoperative neuronavigation. Neuroendoscopy and piezoelectric surgery provided good support in the safe bone removal in close vicinity to neurovascular structures and in full vision inside the cholesteatoma cavity beyond the line of sight of the microscope. Hearing and facial nerve function could be preserved. The presented intracranial retrosigmoid approach combined with multiple intraoperative assisting techniques proved to be effective for the safe and complete removal of recurrent PBC, providing excellent intraoperative visualization and the possibility of preserving cranial nerve function.

Accuracy of turbo spin-echo diffusion-weighted imaging signal intensity measurements for the diagnosis of cholesteatoma

PURPOSE

We aimed to evaluate the diagnostic accuracy of turbo spin-echo diffusion-weighted imaging (TSE-DWI) at 3 T, for cholesteatoma (CS) diagnosis, using qualitative and quantitative methods with numerical assessment of signal intensity (SI), signal intensity ratios (SIR), and apparent diffusion coefficient (ADC) values.

METHODS

In this retrospective study, two blinded observers independently evaluated the preoperative TSE-DWI images of 57 patients who were imaged with a presumed diagnosis of CS. Qualitative assessment with respect to the SI of the adjacent cortex and quantitative measurements of SI, SIR, and ADC values were performed.

RESULTS

Surgery with histopathologic examination revealed 30 CS patients and 27 patients with non-cholesteatoma (NCS) lesions including chronic inflammation and cholesterol granuloma. On TSE-DWI, 96.7% of the CS lesions and none of the NCS lesions appeared hyperintense compared with the cortex. The mean SI and SIR indices of the CS group were significantly higher and the mean ADC values significantly lower compared with those of the NCS group (P < 0.001). Using specific cutoff values for SI (92.5) and SIR (0.9), CS could be diagnosed with 100% sensitivity and specificity. The use of quantitative imaging further increased the sensitivity of the TSE-DWI technique.

CONCLUSION

The quantitative indices of SI, SIR, and ADC of TSE-DWI appear to be highly accurate parameters that can be used to confirm the diagnosis of CS.

Are human ATP-binding cassette transporter C11 and earwax associated with the incidence of cholesteatoma?

Cholesteatoma is an ear disease based on a locally destructive noncancerous conglomerate of epidermis and keratin debris. Abnormal growth of stratified keratinized squamous epithelium in the temporal bone causes destruction of the outer and middle ear, potentially leading to hearing impairment, facial palsy, vertigo, lateral sinus thrombosis, and intracranial complications. Although cholesteatoma is effectively treated by surgical resection (mastoidectomy), the lack of effective and nonsurgical therapies potentially results in fatal consequences, establishing the need for a comprehensive investigation of cholesteatoma pathogenesis. Although its etiology is still being debated, interestingly, we found that the trend associated with the 538G allele frequency of the adenosine triphosphate-binding cassette transporter C11 (ABCC11) gene, the determinant of wet-type earwax, and ethnic groups was similar to that between the incidence of cholesteatoma and ethnic groups (countries). The incidences of cholesteatoma in Europe (Denmark, Finland, and Scotland) are higher than in East Asia (Japan), and the frequencies of the ABCC11 538G allele in African, American, and European (Finland and Scotland) populations are higher than those in East Asian populations (Japan). Additionally, a single-nucleotide polymorphism in the ABCC11 gene (rs17822931, 538G > A; Gly180Arg) is closely related to earwax morphotypes. While earwax is often beneficial to ear health, it is sometimes harmful in cases where it causes hearing impairment. Based on independent findings of associations between ABCC11 and the physiological environment of the auditory canal, we hypothesize a possible link between ABCC11, earwax, and the incidence of cholesteatoma.

Comparison of changes in mitochondrial bioenergetics between keratinocytes in human external auditory canal skin and cholesteatomas from normoxia to hypoxia

Cholesteatoma has attracted many studies seeking to uncover its nature and the pathogenesis of related diseases. However, no researchers have explored the mitochondrial bioenergetics of cholesteatoma. The aim of this study was to investigate the energy demand and differential mitochondrial respiration profiles between keratinocytes in external auditory canal (EAC) skin and cholesteatoma samples cultured in normoxic (20% O₂) and hypoxic (5% O₂) conditions. Enhanced cellular proliferation of both types of keratinocytes was found in hypoxia compared to normoxia. In 20% O₂ conditions, cholesteatoma keratinocytes exhibited less mitochondrial mass, lower ATP levels, and significantly lower basal oxygen consumption rate (OCR) and reserve capacity compared to normal skin keratinocytes. In contrast, in hypoxic conditions, cholesteatoma keratinocytes showed markedly higher levels in maximal OCR and reserve capacity, as well as lower proton leak OCRs, compared to normal skin keratinocytes. Hypoxia induced the reverse mitochondrial bioenergy profile from that in normoxia between these two types of keratinocytes, implying that an adaptive change of mitochondrial respiration to oxygen fluctuations may develop in cases of cholesteatoma. Such adaptation in response to hypoxic conditions may play a role in explaining the pathogenesis of acquired cholesteatoma.

Downregulation of MiR-203a Disinhibits Bmi1 and Promotes Growth and Proliferation of Keratinocytes in Cholesteatoma

Background: Keratinocytes are the predominant cell type in a cholesteatoma, and microRNA (miR)-203a has been shown to be essential for the growth and differentiation of keratinocytes. The regulatory mechanisms of miR-203a and Bmi1-the predicted target of miR-203a that is associated with cholesteatoma-have not been clarified. Methods: Real-time PCR and western blot were carried out for the detection of miRNAs, mRNAs, and proteins, including miR-203a, Bmi1, and phosphorylated (p-)Akt. Immunohistochemical staining was applied to observe the expression and distribution of Bmi1 and of p-Akt in cholesteatoma and in control retroauricular skin. The dual luciferase reporter assay was used to analyze the relationship between miR-203a and Bmi1. Ectopic miR-203a and Bmi1 were transfected into an immortalized line of human keratinocytes (HaCaT cells), and the roles of these molecules in cell proliferation, apoptosis, and migration were explored. Results: Cholesteatoma tissues were characterized by downregulation of miR-203a and concomitant upregulation of Bmi1. Results of the dual-luciferase reporter assay indicated that Bmi1 was a direct target gene of miR-203a. Silencing of miR-203a increased Bmi1 expression; promoted proliferation, colony formation, and migration of HaCaT cells; and inhibited apoptosis. Moreover, p-Akt was significantly increased in cholesteatoma tissues and was positively correlated with Bmi1. Suppression of Bmi1 reduced p-Akt expression in HaCaT cells; subsequent inhibition of miR-203a reversed this phenomenon. Conclusions: Our results reveal that miR-203a may regulate cholesteatoma growth and proliferation by targeting Bmi1. These findings provide insight for the development of novel nonsurgical options for cholesteatoma.

Association Between Middle Ear Cholesteatoma and Chronic Rhinosinusitis

Importance

Chronic rhinosinusitis (CRS) can cause an obstruction of the tubal orifice and thereby compromise ventilation of the middle ear. The resulting negative pressure in the middle ear may, in turn, lead to the formation of an eardrum retraction pocket and subsequent acquired cholesteatoma. This study hypothesizes that CRS may increase the risk of cholesteatoma.

Objective

To evaluate the risk of cholesteatoma in patients with CRS.

Design, Setting, and Participants

This study used a nationwide, population-based claims database to test the hypothesis that CRS may increase the risk of cholesteatoma. The Longitudinal Health Insurance Database of Taiwan was used to compile data from (1) 12 670 patients with newly diagnosed CRS between January 1, 1997, and December 31, 2002, and (2) a comparison cohort of 63 350 matched individuals without CRS, resulting in a CRS vs control ratio of 1:5. Data analysis was performed from June 1 to October 27, 2015. Each patient was followed up for 8 years to identify those in whom cholesteatoma subsequently developed. The Kaplan-Meier method was used to determine the cholesteatoma-free survival rate, and the log-rank test was used to compare survival curves. Cox proportional hazards regression models were used to compute the 8-year hazard ratios (HRs).

Main Outcomes and Measures

Diagnosis of cholesteatoma.

Results

Among the 76 020 patients enrolled in this study, 35 220 (46.3%) were female; mean (SD) age was 27.57 (22.03) years. A total of 209 patients developed cholesteatoma, 66 (101 084 person-years) individuals from the CRS cohort and 143 (506 540 person-years) from the comparison cohort were diagnosed with cholesteatoma during the 8-year follow-up period. The incidence of cholesteatoma per 1000 person-years was more than twice as high among patients with CRS (0.65; 95% CI, 0.50-0.81 person-years) than among those without CRS (0.28; 95% CI, 0.24-0.33). The absolute difference in the incidence density between CRS and non-CRS group was 0.37 (95% CI, 0.21-0.53) per 1000 patient-years. After adjusting for potential confounders, patients with CRS had a 69% increased risk of cholesteatoma within 8 years, compared with those without CRS (HR, 1.69; 95% CI, 1.23-2.32). Patients with CRS presented a significantly lower 8-year cholesteatoma-free survival rate than did those in the comparison group. The absolute difference in the 8-year cholesteatoma-free survival rate between the CRS and non-CRS groups was 0.0029 (95% CI, 0.0016-0.0043).

Conclusions and Relevance

This is the first large-scale study, to date, to demonstrate a prospective link between CRS and the subsequent development of cholesteatoma within a follow-up period of 8 years. The purpose of the study was to draw attention to the possibility of development of cholesteatoma among patients with CRS. Because that possibility exists, clinicians should keep this association in mind as well as the importance of a thorough head and neck examination.

Increased risk of cholesteatoma among patients with allergic rhinitis: A nationwide investigation

OBJECTIVES

No large population-based studies have reported on the risk of cholesteatoma developing after allergic rhinitis (AR). This study used a nationwide population-based claims database to investigate the hypothesis that AR may increase the risk of cholesteatoma.

STUDY DESIGN

Retrospective cohort study.

METHODS

Data from Taiwan's Longitudinal Health Insurance Database were analyzed to compile the following: 1) 15,953 patients newly diagnosed with AR between 1997 and 2000, and 2) a comparison cohort of 63,812 matched non-AR enrollees (with a ratio of 1 to 4). Each patient was followed for 10 years to identify cases in which cholesteatoma subsequently developed. The Kaplan-Meier method was used to determine the cholesteatoma-free survival rate, and the log-rank test was used to compare survival curves. Cox proportional hazard regressions were performed to compute adjusted hazard ratios (HRs).

RESULTS

Among the 79,765 patients enrolled in this study, 45 (159,364 person-years) from the AR cohort and 88 (638,130 person-years) from the comparison cohort were diagnosed with cholesteatoma during the follow-up period (incidence rates 0.28 and 0.14 of 1,000 person-years, respectively). Patients with AR were more likely to develop cholesteatoma compared to those without AR (adjusted HR 1.57, 95% confidence interval = 1.05-2.34, P < 0.05). Patients with AR presented a significantly lower 10-year cholesteatoma-free survival rate than did those in the comparison group (log-rank, P < 0.001).

CONCLUSION

This is the first study to demonstrate a link between AR and the development of cholesteatoma. We suggest that clinicians keep this association in mind and carefully investigate the possibility of development of cholesteatoma among patients with AR.

LEVEL OF EVIDENCE

3b. Laryngoscope, 128:547-553, 2018.

Is Routine Use of High Resolution Computerized Tomography of Temporal Bone in Patients of Atticoantral Chronic Suppurative Otitis Media without Intracranial Complications Justified?

Role of high resolution computerized tomography (HRCT) of temporal bone is established in cases of atticoantral chronic suppurative otitis media (CSOM) with intracranial complications. Routine use of HRCT in management of patients of atticoantral CSOM without intracranial complications has been an issue of debate. The aim of this study was to evaluate the routine use of HRCT of temporal bone in such cases. This study was a prospective study done at LG hospital, AMC MET Medical College, Ahmedabad to evaluate and compare the temporal bone findings in HRCT and intraoperative findings in 100 patients with atticoantral CSOM. All patients underwent HRCT screening followed by surgical exploration of middle ear cleft. In extent of disease HRCT showed very high sensitivity and specificity for epitympanum (100, 94%) and mesotympanum (98, 98%) areas. It gave valuable information of disease extent in hidden areas like sinus tympani and facial recess of mesotympanum. HRCT satisfactorily delineated malleus and incus erosion but had 75% sensitivity for detecting erosion of stapes suprastructure, though specificity was of 97%. For bony anatomical landmarks HRCT showed very high sensitivity and specificity for detecting erosion of lateral semicircular canal, tegmen tympani and sinus plate. Detection of facial canal erosion on HRCT had moderate sensitivity of 75%. We concluded that routine use of HRCT is justified as a reliable preoperative tool in patients with atticoantral CSOM without intracranial complications and it helps to plan type of surgical intervention. HRCT has limited role to distinguish between granulations and cholesteatoma and also to delineate stapes supra structure and facial nerve canal.

Label-free visualization of cholesteatoma in the mastoid and tympanic membrane using CARS microscopy

OBJECTIVE

The present study aimed to evaluate the possibility of using coherent anti-Stokes Raman spectroscopy (CARS) microscopy to determine the specific molecular morphology of cholesteatoma by detecting the natural vibrational contrast of the chemical bonds without any staining.

MATERIALS AND METHODS

Specimens from the mastoid and tympanic membrane with and without cholesteatoma were analyzed using CARS microscopy, two-photon excited fluorescence (TPEF) microscopy, and the second harmonic generation (SHG) microscopy.

RESULTS

In cholesteatoma tissues from the mastoid, a strong resonant signal at 2845 cm-1 was observed by CARS, which indicated the detection of the CH2 hydro-carbon lipid bonds that do not generate visible signals at 2940 cm-1 suggestive of CH3 bonds in amino acids. A strong resonant signal at 2940 cm-1 appeared in an area of the same specimen, which also generated abundant signals by TPEF and SHG microscopy at 817 nm, which was suggestive of collagen. In the tympanic membrane specimen with cholesteatoma, a strong resonant signal with corrugated morphology was detected, which indicated the presence of lipids. A strong signal was detected in the tympanic membrane with chronic otitis media using TPEF/SHG at 817 nm, which indicated collagen enrichment. The CARS and TPEF/SHG images were in accordance with the histology results.

CONCLUSION

These results suggest the need to develop a novel CARS microendoscope that can be used in combination with TPEF/SHG to distinguish cholesteatoma from inflammatory tissues.

The disease recurrence rate after the canal wall up or canal wall down technique in adults

OBJECTIVES/HYPOTHESIS

To review which type of cholesteatoma surgery, canal wall up (CWU) or canal wall down (CWD), provides the lowest risk for residual and/or recurrent disease in adults with primary acquired cholesteatoma.

DATA SOURCES

PubMed, Embase, CINAHL, the Cochrane Library, Scopus and Web of Science.

STUDY DESIGN

We selected articles comparing CWU with CWD, reporting on disease recidivism (combined residual and recurrent disease) or independent residual or disease recurrence rates. We included studies with a moderate to high relevance.

RESULTS

Our search yielded 2,060 articles. We selected seven studies that carried a moderate risk of bias. Six studies described higher disease recidivism after the CWU procedure [16.7-61.0%] compared to the CWD technique [0-13.2%]. Four studies showed statistical significant difference (P < .05). One study showed opposite results: recidivism was found in 7.8% CWU and in 22.1% CWD cases (P < .001). Studies showed CWU recidivism more likely to be residual disease, whereas CWD recidivism tended to be recurrent disease.

CONCLUSION

The majority of included studies showed CWU to result in more disease recidivism compared to the CWD technique in adult patients with a primary acquired cholesteatoma. If recidivism risk is the most important factor to consider a certain surgical technique, we recommend application of the CWD procedure. However, many additional factors in patient care will define the best treatment decision, such as residual hearing and access to health care. Our recommendations are based on Level II evidence, which underlines the need for future high-level evidence studies.