Do the angle and length of the eustachian tube influence the development of chronic otitis media?

Planar Cell Polarity in the Multiciliated Epithelial Lining of the Mouse Eustachian Tube

OBJECTIVES

Planar cell polarity (PCP) signaling, essential for uniform alignment and directional beating of motile cilia, has been investigated in multiciliated epithelia. As a complex structure connecting the middle ear to the nasopharynx, the eustachian tube (ET) is important in the onset of ear-nose-throat diseases. However, PCP signaling, including the orientation that is important for ciliary motility and clearance function in the ET, has not been studied. We evaluated PCP in the ET epithelium.

STUDY DESIGN

Morphometric examination of the mouse ET.

METHODS

We performed electron microscopy to assess ciliary polarity in the mouse ET, along with immunohistochemical analysis of PCP protein localization in the ET epithelium.

RESULTS

We discovered PCP in the ET epithelium. Motile cilia were aligned in the same direction in individual and neighboring cells; this alignment manifested as ciliary polarity in multiciliated cells. Additionally, PCP proteins were asymmetrically localized between adjacent cells in the plane of the ET.

CONCLUSIONS

The multiciliated ET epithelium exhibits polarization, suggesting novel structural features that may be critical for ET function.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3795-3801, 2024.

Age-related morphological change in bony segment and cartilage segment of Eustachian tube

Background

Eustachian tube dysfunction (ETD) is the predominant cause of otitis media with effusion in children and adults. Balloon dilatation of the Eustachian tube (BDET) provides a new method for restoring the ventilatory function of Eustachian tube (ET). However, the differences in age-related morphological changes in the dimensions and positions of ET in children and adults are unclear.

Purpose

This study aimed to examine age-related morphological changes in bony and cartilage segments of the ET in a three-dimensional space in normal population.

Methods

A total of 71 randomly selected computed tomography (CT) images of the temporal bones of 46 people were retrospectively studied in four age groups: A (0-3 years old); B (4-8 years old), C (9-18 years old), and D (19-65 years old). Space analytic geometry was assessed to calculate the dimensions and positions of ET.

Results

The bony segment of ET lengthened from infancy to adulthood with age in groups A, B and C (r = 0.562**/0.000). The cartilage segment of ET mostly extended with age from infancy to 8 years old in children (r = 0.633**/0.000), but with bending close to the sagittal plane and away from the horizontal plane with age in groups A, B and C (P < .05), and with a constant angle to the coronal plane among the four groups (P > .05).

Conclusion

The bony and cartilaginous segments of ET exhibit distinct morphological changes in space with age. The bony segment of ET extends in a constant position from infancy to adulthood. In contrast, the cartilaginous segment of the ET indicates multidimensional positional changes until adulthood, in addition to the elongation from infancy to children. This may provide an accurate morphological basis for comparing the differences in ETD pathogenesis and surgical treatment between children and adults.

Chronic suppurative otitis media

Chronic suppurative otitis media (CSOM) is a leading global cause of potentially preventable hearing loss in children and adults, associated with socioeconomic deprivation. There is an absence of consensus on the definition of CSOM, which complicates efforts for prevention, treatment, and monitoring. CSOM occurs when perforation of the tympanic membrane is associated with severe or persistent inflammation in the middle ear, leading to hearing loss and recurrent or persistent ear discharge (otorrhoea). Cholesteatoma, caused by the inward growth of the squamous epithelium of the tympanic membrane into the middle ear, can also occur. The optimal treatment of discharge in CSOM is topical antibiotics. In resource-limited settings where topical antibiotics might not be available, topical antiseptics are an alternative. For persistent disease, surgery to repair the tympanic membrane or remove cholesteatoma might offer long-term resolution of otorrhoea and potential improvement to hearing. Recent developments in self-fitted air-conduction and bone-conduction hearing aids offer promise as new options for rehabilitation.

Evaluation of Eustachian tube dimensions by temporal bone computed tomography in patients with chronic otitis media

OBJECTIVE

To clarify the relationship between Eustachian tube dimensions and chronic otitis media aetiology using temporal bone computed tomography.

METHODS

The data of 231 adults who had undergone surgery for unilateral chronic otitis media were reviewed retrospectively. Diseased and healthy ears were enrolled in groups 1 and 2, respectively. Group 1A included chronic otitis media with cholesteatoma (n = 28) and group 1B included chronic otitis media without cholesteatoma (n = 203). The Eustachian tube dimensions of groups 1 and 2 were compared, to clarify the relationship between the Eustachian tube dimensions and chronic otitis media aetiology. Groups 1A and 1B were compared to assess the effect of Eustachian tube dimensions on cholesteatoma development.

RESULTS

The Eustachian tube was shorter, narrower and located more horizontally in ears with chronic otitis media. No significant difference was found between groups 1A and 1B.

CONCLUSION

Eustachian tube dimensions are closely related to chronic otitis media aetiopathology, but are not related to cholesteatoma development.

Three-Dimensional Assessment of Eustachian Tube in Patients With Cleft Palate Versus Controls: A CBCT Study

To compare the morphological characteristics of the Eustachian tube (ET) between patients with cleft palate and healthy controls with the use of cone-beam computed tomography (CBCT).

Retrospective assessment of treated nonsyndromic patients with cleft palate and a control group.

CBCT images of 51 patients with cleft palate who had previously undergone surgery to close the cleft palate and a control group of 51 patients were included in this study. Syndromic patients were excluded.

The cleft group were divided into 3 groups according to the palatoplasty technique, which was done in the infancy period to close the cleft palate (Nadjmi modification of Furlow, Sommerlad, and V-Y pushback). Finally, ET length (ETL), ET angle, and auditory tube angle (ATA) were measured in all patients.

The ETL, ETA, and ATA in the cleft and the normal control groups were 29.73 ± 3.14 and 32.18 ± 3.34 mm, 33.18 ± 2.57 and 35.40 ± 3.93, and 141.64 ± 4.13 and 138.87 ± 4.96, respectively. All 3 features were statistically significant among the groups (All Ps < .05). ETL and ETA were significantly higher in Nadjmi modification of Furlow and Sommerlad palatoplasty techniques compared to the V-Y pushback technique, while there was no significant difference in the ATA between the palatoplasty groups.

Cleft palate can significantly affect the morphological characteristics of the ET. Type of the infancy palatoplasty can influence some of its dimensions.

Multiparametric Measurements of the Eustachian tube and Peritubal Region Using Computed Tomography as a Preoperative Workup for Tuboplasty

Background

Eustachian tube dysfunction (ETD) is considered a causative factor for middle ear disease as well as treatment failure. The pathogenesis may be a result of chronic infection, allergy, laryngopharyngeal reflux, primary mucosal disease, dysfunction of the dilation mechanism and anatomical obstruction. Hence, it becomes essential to know the structure and anatomical variations of the Eustachian tube(ET), particularly with the advent of novel therapeutic options such as tuboplasty to ensure optimal therapeutic outcome.

Aims

This cross-sectional study is done to perform multiparametric measurements of the ET and peritubal region using computed tomography and develop a structured protocol for pre-tuboplasty workup.

Materials and methods

This study was done for a period of 20 months, in 100 normal subjects aged between 18 and 60 years, who underwent computed tomography (CT) study of the head and face region, for indications other than nasal/ pharyngeal and sinus disease.

Results

The mean bony, cartilaginous and overall ET lengths were higher in males. In females, the mean ET angles with Reid's plane were higher. Higher mean craniocaudal diameters of the ET lumen were observed in males. Carotid canal dehiscence was seen in equal prevalence on both sides (5%), with no significant gender differences.

Conclusion

Therapeutic interventions such as eustachian tuboplasty will benefit from preoperative imaging based planning. This structured protocol provides standardization of pre-operative workup for tuboplasty.

Caution in Transnasal Balloon Dilation of the Eustachian Tube: Middle Ear Penetration of Catheter Tip in a Cadaveric Model

OBJECTIVE

To investigate the degree to which transnasal eustachian tube (ET) dilation balloon catheters are able to be passed through the ET in a cadaver model.

PATIENTS AND INTERVENTIONS

A cadaveric study of 8 cadaver heads (16 ears), which underwent transnasal ET insertion with a 3 × 20-mm balloon catheter with transtympanic endoscopic visualization and grading.

RESULTS

Catheter tip incursion into the protympanum or mesotympanum occurred in all ears. Radiological validation was obtained with correlation to published ET length data.

CONCLUSION

Middle ear incursion of balloon catheter tips can be demonstrated in a cadaver model and highlights the ongoing need for both caution in novel surgical techniques and evolution in device design.

Disabling hearing loss after Lefort I osteotomies in patients with history of Eustachian tube dysfunction: An unknown complication

INTRODUCTION

The aim of this study was to determine the predisposing factors of this deafness after orthognathic surgery for a population with no history of cleft palate.

MATERIAL AND METHODS

All patients with significant auditory symptoms after orthognathic surgery performed in the department of Craniomaxillofacial surgery in the Croix Rousse Hospital, Lyon, France, since 2012 were included in the study. The exclusion criterion was a history of cleft palate. Bone movements performed during orthognathic surgery were analyzed. An audiometric assessment, including Pure Tone Audiometry and tympanometry, was performed at day 30 (D30), day 60 (D60) and day 90 (D90).

RESULTS

Six patients were included in the study. All patients were women with a mean age of 33.5 years and suffered from class III skeletal deformities. The average hearing loss was 40 dB at D30, 20 dB at D60 and 5 dB at D90 with sometimes differences between the two ears. Five patients had a type C tympanogram suggesting Eustachian tube dysfunction and one patient had a type B tympanogram. All patients benefited from maxillary advancement of 5 mm on average.

DISCUSSION

This study allows to conclude that female patients with a history of allergy or catarrhal tubal deafness are at risk of deafness after orthognathic surgery. These patients must be informed of this complication before surgery and be reassured about its reversibility.

The relationship between dimensions of the Eustachian tube and acquired attic cholesteatoma

Objective

This study investigated the relationship between physical dimensions of the Eustachian tube and the emergence of primary attic cholesteatoma.

Methods

A total of 31 patients with unilateral attic cholesteatoma were selected for radiological comparison. Standard point measurements as well as specific measurements were performed using imaging software. The length, narrowest diameter and bony segment volume, and pharyngeal orifice diameter of both sides of the Eustachian tube (attic cholesteatoma and healthy control ears) were measured and compared.

Results

Comparison of the values did not reveal any statistically significant difference between the attic cholesteatoma ears and the healthy control ears in terms of: Eustachian tube height, narrowest diameter, bony segment volume or pharyngeal orifice diameter.

Conclusion

No statistically significant difference was found between the cholesteatoma ears and the healthy control ears in terms of the osseous Eustachian tube size. The findings indicate that the Eustachian tube bony segment dimensions and pharyngeal orifice diameter are not factors in attic cholesteatoma development.

Study of the Reliability of High Resolution CT Scan Evaluation of Eustachian Tube as Predictor of Predisposition for Chronic Otitis Media

Eustachian tube (ET) dysfunction is one of the predisposing factors for chronic otitis media (COM). This study looks at two parameters in High Resolution Computed Tomography of temporal bone namely tubotympanic angle (TTA) and pretympanic diameter (PTD) and its relationship with COM. The objectives of the study were to compare the tubotympanic angle and pretympanic diameter of the affected ear in patients with unilateral COM with that of healthy controls, and with contralateral non-COM ear. This was a retrospective study done at a tertiary referral hospital. Database of patients who underwent high resolution CT scan of temporal bone over a period of  three and half years, was studied. The TTA and PTD of ET were measured with the help of a senior radiologist well-versed in the imaging of temporal bone. Group A consisted of 45 patients with unilateral COM, while Group B comprised 50 patients without COM. Group A was further subgrouped as A1 (COM with cholesteatoma) and A2 (COM without cholesteatoma). The TTA and PTD in COM with cholesteatoma in the affected ear were 147.98 ± 5.89° and 2.84 ± 0.82 mm respectively, and in the unaffected ear, 144.81 ± 6.43° and 3.32 ± 1.19 mm respectively. In Group A, the TTA and PTD in the affected ear of unilateral COM were 146.17 ± 6.11°, 2.97 ± 0.87 mm and in Group B, it was 143.17 ± 6.01° and 3.48 ± 0.85 mm respectively. All these were statistically significant (p value < 0.05). Increased TTA and reduced PTD of ET may be a predisposing factor for the development of COM and cholesteatoma.

Radiological dimensions of the Eustachian tube in patients with adhesive otitis media

OBJECTIVE

This study aimed to analyse the computed tomography parameters for effective ventilation in patients with adhesive otitis media.

METHODS

Twenty-six patients with unilateral adhesive otitis media were included in the study. The patients' temporal bone computed tomography images were retrospectively reviewed. Eustachian tube length and diameter were measured. Mastoid pneumatisation and middle-ear size were evaluated by measuring petroclival and Eustachian tube-tympanic cavity ventilation angles.

RESULTS

The average Eustachian tube length was 38.4 mm and 38.9 mm in adhesive otitis media and healthy ears, respectively. The Eustachian tube diameter of the adhesive otitis media ears (1.47 mm) was significantly narrower than that of the healthy ears (1.83 mm). There were no significant differences in the angles between adhesive otitis media and healthy ears.

CONCLUSION

A narrow Eustachian tube diameter was associated with developing adhesive otitis media. Measuring Eustachian tube diameter is simple and can be routinely performed when examining temporal bone computed tomography images for Eustachian tube function evaluation.

A new "practical" plane for Eustachian tube measurements and its application in predicting middle ear dysfunction in patient with acquired cholesteatomas

Setting

The Eustachian tube plays a vital role in middle ear physiology. There has been evidence that Eustachian tube (ET) and angle are correlated with middle ear function. The measurements of these Eustachian tube features are now made possible with computed tomography and multiplanar reconstruction techniques. However, there has not been a standardised protocol devised to these measurements in limited window cone-beam CT scans of temporal bones.

Objective

The primary object of the present study is to establish and validate a new landmark in closer proximity to the middle ear that is consistently captured, thereby allowing ET angle and length to be measured from the majority of cone-beam CT scans. Secondarily, the ET anatomies of patients with middle ear dysfunction manifesting as acquired cholesteatoma are analysed with this new method of measurement.

Methods

This study undertook a step-by-step method to first validate the methods of ET measurement with Reid’s standard plane, then identifying an alternative landmark, thus a new plane visible on limited window cone-beam CT scans of temporal bones and lastly, validating the application of this new plane in the measurements of ET angle and length. This new method of measurement was coined the Ku-Copson plane and was applied to 30 cochlear implant patients and 30 patients with acquired cholesteatomas. Their ET anatomies were analysed and compared.

Results

It was found that the new Ku-Copson mandibular fossa plane was a reliable and accurate plane for the measurement of ET angle and length. Furthermore, it was found that patients with acquired cholesteatomas have statistically significant smaller ET angles and shorter ET lengths when compared with patients with cochlear implants, of normal middle ear function.

Conclusion

The newly proposed method utilising the right mandibular fossa as an anatomical landmark for ET angles and lengths measurement appears to be viable. The close proximity of this landmark to the middle ear means that it is highly likely to be captured in most cone-beam CT scans of the petrous temporal bones. This enables the retrospective examination ET angles and lengths to be conducted on CB CT scans. This study reports statistically significant difference in ET anatomy in patients with middle ear dysfunction.

The association of iron deficiency anemia on chronic suppurative otitis media in children: A case-control study

Background

Chronic suppurative otitis media (CSOM) is the most common infectious disease in the world and the leading cause of hearing loss in children in developing countries. Iron deficiency anemia (IDA) is often found in children with CSOM.

Objective

This study was conducted to determine the association between IDA and the incidence of CSOM in children.

Method

This research is a case-control study using consecutive sampling. Participants were divided into case group which are children diagnosed with CSOM (n = 42) and control group which are children with normal ear (n = 42). All participants were examined for serum iron (FE), hemoglobin (Hb), total iron-binding capacity (TIBC), and ferritin levels. The analysis used in this study includes the chi-square test or fisher extract test and independence t-test or Man Whitney test with p < 0.05.

Result

The measurement results obtained values of Hb (13.00 ± 1.34 g/dL; p < 0.001), FE (95.13 ± 40.84 g/dL; p < 0.001), TIBC (354.18 ± 62.44 g/dL; p = 0.016), and ferritin levels (17.57 ± 8.55 g/dL; p < 0.001). Participants who experienced IDA were 21.43% which in the case group was 31.0% and control group was 11.9% (OR = 3.32; p = 0.033).

Conclusion

IDA can increase the incidence of CSOM in children.

•

Iron deficiency anemia is a risk factor for CSOM in Children.

•

Children with iron deficiency anemia have a 3-fold risk of experiencing CSOM.

•

Supplement iron needs to be given as a preventative for CSOM in children.

Does Ostmann's fat pad size correlate with development of chronic otitis media in children?

OBJECTIVE

To compare Ostmann's fat pad (OFP) size between healthy ears and ears with chronic otitis media with cholesteatoma (COMwC) in children, to assess its role in the disease.

METHODS

MRI scans of 29 children with unilateral COMwC with conductive hearing loss were used to measure OFP, represented by the maximal diameter of the high intensity area medial to the tensor veli palatini muscle (TVP): M1. A reference diameter was defined from the medial border of OFP reaching the medial border of the medial pterygoid muscle: M2. Values of M1, M2 and the ratio of M1:M2 were compared between the healthy and pathological ear in each patient.

RESULTS

No difference in OFP size was observed between healthy (H) ears (mean M1H:M2H ratio 0.72 ± 2.28) compared to ears with COMwC pathology (P) (mean M1P:M2P ratio .68 ± 1.57; P = .943) in children, suggesting that OFP size abnormalities do not have a role in pediatric COMwC.

CONCLUSION

OFP size was not correlated to the development of unilateral COMwC in children.

Developmental Anatomy of the Eustachian Tube: Implications for Balloon Dilation

OBJECTIVE

To describe the developmental anatomy of the eustachian tube (ET) and its relationship to surrounding structures on computed tomography.

STUDY DESIGN

Case series with chart review.

SETTING

A tertiary care hospital.

METHODS

ET anatomy was assessed with reformatted high-resolution computed tomography scans from 2010 to 2018. Scans (n = 78) were randomly selected from the following age groups: <4, 5 to 7, 8 to 18, and >18 years. The following were measured and compared between groups: ET length, angles, and relationship between its bony cartilaginous junction and the internal carotid artery and between its nasopharyngeal opening and the nasal floor.

RESULTS

The distance between the bony cartilaginous junction and internal carotid artery decreased with age between the <4-year-olds (2.4 ± 0.6 mm) and the 5- to 7-year-olds (2.0 ± 0.3 mm, P = .001). The ET length increased among the <4-year-olds (32 mm), 5- to 7-year-olds (36 mm), and 8- to 18-year-olds (41 mm, P < .0001). The cartilaginous ET increased among the <4-year-olds (20 mm), 5- to 7-year-olds (25 mm), and 8- to 18-year-olds (28 mm, P < .0001). The ET horizontal angle increased among the <4-year-olds (17°), 5- to 7-year-olds (21°), and 8- to 18-year-olds (23°, P≤ .003), but the ET sagittal angle did not statistically change after 5 years of age. The height difference between the nasopharyngeal opening of the ET and the nasal floor increased among the <4-year-olds (4 mm), 5- to 7-year-olds (7 mm), and 8- to 18-year-olds (11 mm, P < .0001).

CONCLUSION

The ET elongates with age, and its angles and relationship to the nasal floor increase. Although some parameters mature faster, more than half of the ET growth occurs by 8 years of age, and adult morphology is achieved by early adolescence.

Morphologic measurements of 3D Eustachian tube model and their diagnostic value regarding Eustachian tube dysfunction - A cross-sectional observational study

PURPOSE

To investigate the diagnostic value of three-dimensional morphologic measurements of the Eustachian tube on computed tomography in Eustachian tube dysfunction.

METHOD

This prospective cross-sectional observational study includes forty patients with unilateral Eustachian tube dysfunction. The clinical diagnosis is verified using the Eustachian tube score - 7 and the Eustachian tube dysfunction questionnaire - 7. Computed tomography scans of the temporal bone are acquired while performing a Valsalva manoeuvre to improve the visualization of the air-filled Eustachian tube lumen. The Eustachian tubes are delineated on curved planar reconstructions, and three-dimensional models are constructed. Seven morphological parameters are measured for each Eustachian tube: the cross-sectional size of the tympanic and pharyngeal orifice; the visualization length; the inclination angles, and the curvature angles. Morphological measurements and Eustachian tube scores are correlated.

RESULTS

The mean value of the visualization length of the complete Eustachian tube and in its bony segment is significantly higher in healthy sides than in pathological sides (p = 0.034 and p = 0.029, respectively). There is a significant correlation between the Eustachian tube score - 7 and the cross-sectional size of the tympanic orifice (r_P = 0.361; p = 0.022). The Eustachian tube score - 7 correlates significantly with the visualization length of complete Eustachian tube (r_P = 0.436; p = 0.005) and its bony segment (r_S = 0.598; p < 0.0001), respectively.

CONCLUSIONS

The cross-sectional size of the tympanic orifice may be a specific imaging feature indicating the obstructive Eustachian tube. However, 3D morphologic measurements of the Eustachian tube are insufficient to yield useful data about its function.

Eustachian Tube: Computed Tomography Analysis

BACKGROUND

Eustachian tube has a major role in ventilation, drainage, and protection of the middle ear. High resolution computed tomography magnifies the role of preoperative imaging for detailed inner and middle ear anatomical information. The aim of this study was to find an applicable way by computed tomography imaging for assessment of Eustachian tube. The goal was to provide improved understanding of the Eustachian tube measurements and the relationship with middle ear in Egyptian population. Computed tomography measurements for Eustachian tube were done including; length of the bony and cartilaginous portions, Total length of Eustachian tube, as well as the width and height of the tympanic orifice of the Eustachian tube. Also, tubotympanic and Reid plane- Eustachian tube angles were measured.

RESULTS

Within 200 studied ears in 100 subjects, the mean total Eustachian tube length was 40.19 ± 3.05 mm, mean length of the bony Eustachian tube was 11.69 ± 1.8 mm with significant longer Eustachian tube on left side, The mean length of the cartilaginous Eustachian tube was 28.5 ± 2.95 mm with significantly longer cartilaginous and total length in male (P < 0.0001). The mean width and height of the tympanic orifice of the Eustachian tube was 5.4 ± 0.79 and 4.85 ± 0.75 mm, respectively. The mean tubotympanic angle of the Eustachian tube was 148.11 ± 2.82°. The mean Reid plane- Eustachian tube angle was 27.69 ± 2.08° with significantly wider angle in males (P < 0.022).

CONCLUSION

The Eustachian tube measurements can easily be obtained on computed tomography images, and are representative for the Eustachian tube anatomy. There is importance of extending computed tomography examinations beyond the middle ear cavity and the mastoids to the Eustachian tube in order to have more data on its condition and relations with different pathological conditions. Computed tomography provides improved understanding of the Eustachian tube measurements and relationship with middle ear structures.

Evaluation of the relationship of chronic otitis media with the Körner's septum, auditory tube angle, and tubotympanic angle

PURPOSE

This study aimed to evaluate the relationships between chronic otitis media (COM) and the characteristics of Auditory tube (Eustachian) angle (ATa), tubotympanic angle (TTa), and Körner's septum (KS).

METHODS

A retrospective research was conducted between January 2019 and October 2019. The computed tomography (CT) results and medical files of 210 patients were evaluated. According to CT results and medical files, the patients were evaluated regarding the presence of COM, KS, ATa, and TTa.

RESULTS

There were 113 (53.81%) males and 97 (46.19%) females in the study group, and the mean age of the patients was 42.05 ± 10.77 years. The frequency of the KS was significantly higher in patients who were diagnosed with COM (35.66% vs. 7.41%, p < 0.001). The patients diagnosed with COM were found to have a narrower ATa and a wider TTa than the patients who were not diagnosed with COM. ATa was narrower and TTa was wider in patients with KS. The presence of KS and higher TTa value were considered as risk factors for COM (p < 0.001, p < 0.001, respectively) CONCLUSION:  Our findings indicate that ATa was narrower, TTa was wider and KS was more frequent in patients with COM. Analysis of risk factors demonstrated that increased TTa and the presence of KS were associated with increased risk for COM.

Cone-Beam Computed Tomography Evaluation of the Eustachian Tube in Patients With Cleft Lip and Palate Compared With Normal Controls

The authors compared the morphological features of the Eustachian tube (ET) between patients with cleft lip and palate (CL/P) and normal controls using cone-beam computed tomography (CBCT). CBCT images of 51 CL/P patients (28 males and 23 females, mean age: 18.5 ± 8.0 years) and a control group of 52 patients (22 males and 30 females, mean age: 25.23 ± 10.65 years) were retrospectively evaluated. The Eustachian tube angle (ETA), Eustachian tube length (EL), and auditory tube angle (ATA) were measured on CBCT images. The ETA, EL, and ATA in the CL/P and normal control groups were 30.4 ± 6.2 and 36.7 ± 7.5°; 24.7 ± 3.7 and 27.7 ± 4.3 mm; and 142.4 ± 7.8 and 136.3 ± 4.1°, respectively. All between-group differences were statistically significant (all P < 0.05). There were no significant between-gender differences in either group (all P > 0.05). Continuous variables were compared using the Mann-Whitney U-test. The morphological features of the ET, measured via multiplanar reconstruction CBCT, differed between CL/P patients and normal controls. CBCT can be used to evaluate ET morphological features.

Anatomical Limits of the Endoscopic Contralateral Transmaxillary Approach to the Petrous Apex and Petroclival Region

Objectives This study aimed to establish the anatomical landmarks for performing a contralateral transmaxillary approach (CTM) to the petrous apex (PA) and petroclival region (PCR), and to compare CTM with a purely endoscopic endonasal approach (EEA).

Design EEA and CTM to the PA and PCR were performed bilaterally in eight human anatomical specimens. Surgical techniques and anatomical landmarks were described, and EEA was compared with CTM with respect to ability to reach the contralateral internal acoustic canal (IAC). Computed tomographic scans of 25 cadaveric heads were analyzed and the “angle” and “reach” of CTM and EEA were measured.

Results Entry to the PA via a medial approach was limited by (1) abducens nerve superiorly, (2) internal carotid artery (ICA) laterally, and (3) petroclival synchondrosis inferiorly (Gardner's triangle). With CTM, it was possible to reach the contralateral IAC bilaterally in all specimens dissected, without dissection of the ipsilateral ICAs, pterygopalatine fossae, and Eustachian tubes. Without CTM, reaching the contralateral IAC was possible only if: (1) angled endoscopes and instruments were employed or (2) the pterygopalatine fossa was dissected with mobilization of the ICA and resection of the Eustachian tube. The average “angle” and “reach” advantages for CTM were 25.6-degree greater angle of approach behind the petrous ICA and 1.4-cm more lateral reach.

Conclusion The techniques and anatomical landmarks for CTM to the PA and PCR are described. Compared with a purely EEA, the CTM provides significant “angle” and “reach” advantages for the PA and PCR.

Current Understanding of Host Genetics of Otitis Media

The pathogenesis of otitis media (OM), an inflammatory disease of the middle ear (ME), involves interplay between many different factors, including the pathogenicity of infectious pathogens, host immunological status, environmental factors, and genetic predisposition, which is known to be a key determinant of OM susceptibility. Animal models and human genetics studies have identified many genes and gene variants associated with OM susceptibility: genes that encode components of multiple signaling pathways involved in host immunity and inflammatory responses of the ME mucosa; genes involved in cellular function, such as mucociliary transport, mucin production, and mucous cell metaplasia; and genes that are essential for Eustachian tube (ET) development, ME cavitation, and homeostasis. Since our last review, several new mouse models with mutations in genes such as CCL3, IL-17A, and Nisch have been reported. Moreover, genetic variants and polymorphisms in several genes, including FNDC1, FUT2, A2ML1, TGIF1, CD44, and IL1-RA variable number tandem repeat (VNTR) allele 2, have been identified as being significantly associated with OM. In this review, we focus on the current understanding of the role of host genetics in OM, including recent discoveries and future research prospects. Further studies on the genes identified thus far and the discovery of new genes using advanced technologies such as gene editing, next generation sequencing, and genome-wide association studies, will advance our understanding of the molecular mechanism underlying the pathogenesis of OM and provide new avenues for early screening and developing effective preventative and therapeutic strategies to treat OM.

Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review

BACKGROUND

Cerebrospinal fluid rhinorrhea from a lateral skull base defect refractory to spontaneous healing and/or conservative management is most commonly managed via open surgery. Approach for repair is dictated by location of the defect, which may require surgical exploration. The final common pathway is the eustachian tube (ET). Endoscopic ET obliteration via endonasal and lateral approaches is under development. Whereas ET anatomy has been studied, surgical landmarks have not been previously described or quantified. We aimed to define surgical parameters of specific utility to endoscopic ET obliteration.

METHODS

A literature review was performed of known ET anatomic parameters. Next, using a combination of endoscopic and open techniques in cadavers, we cannulated the intact ET and dissected its posterior component to define the major curvature position of the ET, defined as the genu, and quantified the relative distances through the ET lumen. The genu was targeted as a major obstacle encountered when cannulating the ET from the nasopharynx.

RESULTS

Among 10 ETs, we found an average distance of 23 ± 5 mm from the nasopharynx to the ET genu, distance of 24 ± 3 mm from the genu to the anterior aspect of the tympanic membrane and total ET length of 47 ± 4 mm.

CONCLUSIONS

Although membranous and petrous components of the ET are important to its function, the genu may be a more useful surgical landmark. Basic surgical parameters for endoscopic ET obliteration are defined.

The cartilaginous Eustachian tube: Reliable CT measurement and impact of the length

PURPOSE

Balloon dilation of the Eustachian tube is a treatment option for obstructive Eustachian tube dysfunction. The desired balloon position is in the cartilaginous portion. However, the balloon catheter may slide into the bony portion without the surgeon's knowledge. Knowing the length of the cartilaginous portion may improve catheter positioning, but there is no published research on measuring this portion selectively or on whether the length has an impact on development of disease or treatment outcome. To evaluate whether a measurement obtained from CT images is valuable and accurate, to standardize the manner of which the length is measured, and to compare our radiologic measurements to procedural findings, we designed a combined study. Further, we tested the length's influence on development of disease and treatment outcome.

METHODS

Anatomical end points of the cartilaginous part of the Eustachian tube were unambiguously defined. The length was retrospectively measured bilaterally in 29 CT examinations by two radiologists, and repeated by one after two weeks. New reformats and measurements were made after 18 months for 10 of the patients. Prospectively 10 patients were included in a study where the length measured on CT was compared to per-procedural measurements based on catheter insertion depth to isthmus. Various parameters including length and treatment outcome were measured in 69 patients and 34 controls.

RESULTS

Correlation was adequate to excellent in all comparisons. The length of the cartilaginous Eustachian tube did not predict treatment outcome or disease development. The lengths were significantly shorter in females.

CONCLUSION

Measuring the cartilaginous portion of the Eustachian tube on CT images is precise and reproducible, and reflects the length measured intraoperatively. However, it does not seem have a prognostic value.

Do the Angle and Length of the Eustachian Tube Affect the Success Rate of Pediatric Cartilage Type 1 Tympanoplasty?

OBJECTIVES

To investigate the relationships between the angle and length of the Eustachian tube (ET) (the ETa and the ETl) and the success rates of pediatric type 1 tympanoplasty.

STUDY DESIGN

A retrospective clinical chart review.

METHODS

In total, 51 children (31 females and 20 males; average age, 11.92 ± 3.46 years; age range: 7-18 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. In group A, all patients had intact grafts without perforation, retraction, or lateralization, and a dry ear, at 6 months postoperatively. In group B, reperforation of the tympanic membrane was evident 6 months postoperatively. The average ETa and ETl values of each group were measured on computed tomography images using a multiplanar reconstruction technique, and compared.

RESULTS

The ETa values of diseased ears of males and females were, respectively, 26.60 ± 6.42° and 23.29 ± 6.51°, compared to 27.25 ± 5.23° and 23.32 ± 4.61° for normal male and female ears, respectively. In group A, the ETa was 26.46 ± 6.82° in males and 22.95 ± 7.50° in females. In group B, the ETa was 26.85 ± 6.12° in males and 23.90 ± 4.45° in females. In group A, the mean ETl was 41.0 mm (29.6-45.3 mm) in males and 37.9 mm (32.0-44.5 mm) in females. In group B, the mean ETl was 40.5 mm (30.5-47.1 mm) in males and 38.0 mm (32.8-45.0 mm) in females. In group A, the ETa value of diseased ears did not differ between females and males, but in normal ears, the ETa was higher in males than females (P = 0.020 and P < 0.05, respectively). In group B, no difference was evident between the ETa values of normal and diseased ears (P > 0.05). No difference in the ETl values of diseased and normal ears, in either group, was apparent between females and males (both P > 0.05).

CONCLUSIONS

Neither the ETa nor the ETl affected the success rate of pediatric cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to compare anatomical outcomes after placement of various graft types and the effects of anatomical features of the ET on the success rate of pediatric tympanoplasty.

Eustachian tube diameter: Is it associated with chronic otitis media development?

OBJECTIVE

To evaluate the effect of ET diameter on Chronic Otitis Media (COM) pathogenesis.

STUDY DESIGN

Retrospective.

SUBJECTS AND METHODS

Patients with unilateral COM disease are included in the study. The connection between fibrocartilaginous and osseous segments of the Eustachian Tube (ET) on axial Computed Tomography (CT) images was defined and the diameter of this segment is measured. The measurements were carried out bilaterally and statistically compared.

RESULTS

154 (76 (49%) male, 78 (51%) female patients were diagnosed with unilateral COM and included in the study. The mean diameter of ET was 1947mm (Std. deviation±0.5247) for healthy ears and 1788mm (Std. deviation±0.5306) for diseased ears. The statistical analysis showed a significantly narrow ET diameter in diseased ear side (p<0.01).

CONCLUSION

The dysfunction or anatomical anomalies of ET are correlated with COM. Measuring of the bony diameter of ET during routine Temporal CT examination is recommended for our colleagues.

Tensor veli palatini electromyography for monitoring Eustachian tube rehabilitation in otitis media

BACKGROUND

The pathogenesis of otitis media is related to Eustachian tube dysfunction. The tensor veli palatini muscle actively opens the Eustachian tube and promotes middle-ear ventilation. This study describes a technique for paratubal electromyography that uses a surface, non-invasive electrode able to record tensor veli palatini muscle activity during swallowing.

METHODS

Twenty otitis media patients and 10 healthy patients underwent tensor veli palatini electromyography. Activity of this muscle before and after Eustachian tube rehabilitation was also assessed.

RESULTS

In 78.5 per cent of patients, the electromyography duration phase and/or amplitude were reduced in the affected side. The muscle action potential was impaired in all patients who underwent Eustachian tube rehabilitation.

CONCLUSION

This study confirmed that Eustachian tube muscle dysfunction has a role in otitis media pathogenesis and showed that muscle activity increases after Eustachian tube rehabilitation therapy.

Intranasal fluticasone associated with delayed tympanostomy tube placement in children with eustachian tube dysfunction

OBJECTIVES

Pediatric patient caregivers may prefer to avoid a surgical intervention and request a medical management option for eustachian tube dysfunction (ETD). However, there are limited published data evaluating the efficacy of intranasal fluticasone in the medical management of ETD as an alternative to tympanostomy tube placement. The objectives of this study were to: 1) determine if intranasal fluticasone (INF) prevented tympanostomy tube placement in children with ETD, and 2) describe differences in patient response to INF related to cleft lip and/or palate (CLP) and Down syndrome.

METHODS

Case series with planned chart review at a Tertiary academic hospital. We reviewed pediatric patients treated with INF for ETD. Inclusion criteria included ETD, no prior intranasal or oral steroid therapy, and no prior tympanostomy tube placement. Outcomes included time-to- tympanostomy tube placement with or without INF and therapy compliance. Kaplan-Meier survival analyses with log-rank tests and Fisher's exact tests were used to examine outcome variables.

RESULTS

676 fulfilled inclusion criteria. 393 (58.7%) were male, and 355 (52.5%) Caucasian with mean age of 27.1 months old. 92 (13.6%) had CLP and 46 (6.8%) had Down Syndrome. 266 (39.4%) received INF, and 202 (88.2%) were compliant at their next visit. 474 (70.1%) had tympanostomy tubes placed. Children treated with INF were less likely to have tympanostomy tubes placed than children not treated (52.6% vs. 81.5%; p < 0.0001). Using survival analyses, INF use was associated with significantly longer mean time-to-tympanostomy tube than no INF use (199.4 vs. 133.7 days; p < 0.0001). INF did not reduce time-to-tympanostomy tube in patients with CLP (p = 0.05) or Down Syndrome (p = 0.27).

CONCLUSION

INF significantly reduces the number of children requiring tympanostomy tube placement for ETD. The CLP and Down Syndrome anatomical variants may attenuate INF efficacy. Further in vivo characterization of INF action on eustachian tube tissues will help further substantiate these observations.

Comparison of temporalis fascia muscle and full-thickness cartilage grafts in type 1 pediatric tympanoplasties

Introduction

Various graft materials have been used to close tympanic membrane perforations. In the literature, there are few studies in pediatric populations comparing different graft materials. To our knowledge, there is no reported study that measured the thickness of the tragal cartilage in pediatric tympanoplasties. The tragal cartilage is not of uniform thickness in every patient.

Objective

To compare anatomical and functional outcomes of temporalis fascia muscle and full-thickness tragal cartilage in type 1 pediatric tympanoplasties.

Methods

In total, 78 patients (38 males, 40 females; average age 10.02 ± 1.98 years; range, 7–18 years) who underwent type 1 tympanoplasties in our clinic were included. Demographics, anatomical, and functional outcomes were collected. Temporalis fascia muscle and tragal cartilage were used as graft materials. Tragal cartilage was used without thinning, and the thickness of tragal cartilage was measured using a micrometer. Anatomical and functional outcomes of cartilage and fascia were compared. Audiometric results comparing the cartilage and fascia groups were conducted at 6 months, and we continued to follow the patients to 1 year after surgery. An intact graft and an air-bone gap ≤ 20 dB were regarded as a surgical success. Results with a p-value < 0.05 were considered statistically significant.

Results

The graft success rate was 92.1% for the cartilage group compared with 65.0% for the temporal fascia group. In the fascia group, the preoperative air-bone gap was 33.68 ± 11.44 dB and postoperative air-bone gap was 24.25 ± 12.68 dB. In the cartilage group, the preoperative air-bone gap was 35.68 ± 12.94 dB and postoperative air-bone gap was 26.11 ± 12.87 dB. The anatomical success rate in the cartilage group was significantly better than that for the fascia group (p < 0.01). There was no statistically significant difference in functional outcomes between the fascia and cartilage groups (p > 0.05). The average thickness of tragal cartilage in the pediatric population was 0.693 ± 0.094 mm in males and 0.687 ± 0.058 mm in females.

Conclusions

Our data suggest that the anatomical success rate for a cartilage tympanoplasty was higher than for a fascia tympanoplasty. Functional results with cartilage were not different than with fascia, even though we did not thin the tragal cartilage. However, further studies should focus on the interaction between the thickness of the tragal cartilage and the tympanoplasty success rate.

The Effect of the Angle and Length of the Eustachian Tube on the Success Rate of Cartilage Type 1 Tympanoplasty

OBJECTIVES

To explore the relationships between the angle and length of the eustachian tube (ET) (the ETa and the ETl) and the success rates of type 1 tympanoplasty.

STUDY DESIGN

A retrospective clinical chart review.

METHODS

In total, 160 patients (81 females and 79 males; average age, 37.12 ± 12.46 years; age range: 18-65 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. The average ETa and ETl values of each group were measured on computed tomography images using a multiplanar reconstruction technique, and compared. A P value <0.05 was considered to reflect statistical significance.

RESULTS

In group A, the ETa of diseased ears was 27.74 ± 12.06° in males and 21.87 ± 7.58° in females. In group A, the ETa of normal ears was 27.53 ± 4.15° in males and 22.25 ± 4.67° in females. In group B, the ETa of diseased ears was 28.85 ± 6.19° in males and 22.91 ± 5.65° in females. In group B, the ETa of normal ears was 27.71 ± 5.23° in males and 23.72 ± 6.20° in females. In group A, the mean ETl of diseased ears was 42.1 mm (28.9-45.1) in males and 38.2 mm (31.0-44.7) in females. In group A, the mean ETl of normal ears was 41.9 mm (29.2-45.8) in males and 37.4 mm (30.5-44.1) in females. In group B, the mean ETl of diseased ears was 40.8 mm (30.2-47.4) in males and 37.9 mm (31.8-45.2) in females. In group B, the mean ETl of normal ears was 41.6 mm (30.0-45.0) in males and 39.1 mm (30.0-43.7) in females. In group A, the ETa value of diseased ears did not differ between females and males, but in normal ears the ETa was higher in males than females (P =0.002 and P <0.05, respectively). In group B, no difference was evident between the ETa values of normal and diseased ears (P >0.05). No difference in the ETl values of diseased and normal ears, in either group, was apparent between females and males (both P >0.05).

CONCLUSION

Neither the ETa nor the ETl affected the success rate of cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to compare anatomical outcomes after placement of various graft types and the effects of anatomical features of the ET on the success rate of type 1 tympanoplasty.

Recovery time for inflamed middle ear mucosa in chronic otitis media

CONCLUSION

The present study shows that 2-3 weeks after medical treatment the status of middle ear mucosa in draining ears is similar to that of dry ears for at least 3 months.

OBJECTIVE

To measure the time required for an inflamed middle ear mucosa to return into optimal state after appropriate medical treatment in chronic suppurative otitis media (CSOM). To assess optimal timing for elective surgical treatment of draining ears in uncomplicated CSOM.

METHODS

In this prospective study, the Eustachian tube (ET) mucociliary clearance time (MCT) was used as the method to demonstrate the status of middle ear mucosa. In group 1 (28 patients) ET-MCT was measured in ears that were free of drainage for at least 3 months. In Group 2 (21 patients), ET-MCT was measured in draining ears, who responded to 10-14 days medical treatment, at presentation, after 10 days and 1 month.

RESULTS

The ET-MCT was 8.63 ± 1.32 min in group 1 and 28.96 ± 8.19 min in group 2 at presentation; and the difference was statistically significant (p < 0.001). The ET-MCT was 14.76 ± 5.11 min after 10 days and 9.31 ± 2.33 min after 1 month in group 2. The ET-MCT was indifferent between groups 1 and 2 after 1 month (p = 0.235).