A Multicenter, Single-Arm, Objective Performance Criteria-Controlled Clinical Study of the Safety and Efficacy of the Double-Lumen Eustachian Tube Balloon Catheter.

BACKGROUND: To prospectively evaluate the technical efficacy and safety of the double-lumen eustachian tube (ET) balloon catheter in patients with ET dysfunction. METHODS: Patients who were diagnosed with ET dysfunction and needed balloon eustachian tuboplasty (BET) were prospectively enrolled. A double-lumen ET balloon catheter was used to dilate the ET and inject medicine. Efficacy results were assessed by the injection channel patency (ICP) rate, the injection reached the expected site (IRES) rate, and the improvement in eustachian tube function was evaluated by the seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) score. Safety results were assessed in terms of adverse events and device defects. RESULTS: BET was successfully attempted in 87 patients from April 2022 to August 2022 at two academic medical centers in China (01, 02). The ICP rate was 100%, and the IRES rate was 88.51%. The overall ETDQ-7 score was significantly reduced ( p < 0.001) postsurgically at both centers. There were no major complications or device defects. CONCLUSION: The double-lumen ET balloon catheter is technically effective and safe for the treatment of ET dysfunction.

Genome-wide association study indicates novel associations of annexin A13 to secretory and GAS2L2 with mucous otitis media.

To evaluate the genetics of chronic nonsuppurative otitis media (OM). We performed a genome-wide association study of 429,599 individuals included in the FinnGen study using three different case definitions: combined chronic nonsuppurative OM (7034 cases) (included serous and mucous chronic OM), mucous chronic OM (5953 cases), and secretory chronic OM (1689 cases). Individuals without otitis media were used as controls (417,745 controls). We used immunohistochemistry (IHC) of the murine middle ear to evaluate the expression of annexin A13. Four loci were significantly associated (p < 1.7 × 10-8) with nonsuppurative OM. Three out of the four association signals included missense variants in genes that may play a role in otitis media pathobiology. According to our subtype-specific analyses, one novel locus, located near ANXA13, was associated with secretory OM. Three loci (near TNFRSF13B, GAS2L2, and TBX1) were associated with mucous OM. Immunohistochemistry of murine middle ear samples revealed annexin A13 expression at the apical pole of the Eustachian tube epithelium as well as variable intensity of the secretory cells of the glandular structure in proximity to the Eustachian tube. We demonstrated that secretory and mucous OM have distinct and shared genetic associations. The association of GAS2L2 with ciliary epithelium function and the pathogenesis of dysfunctional mucosa in mucous OM is suggested. The abundant expression of annexin A13 in the Eustachian tube epithelium, along with its role in apical transport for the binding and transfer of phospholipids, indicates the role of annexin A13 and phospholipids in Eustachian tube dysfunction.

Evaluation of the Peritubal Region Between the Osseous Eustachian Tube and the Internal Carotid Artery: Usefulness of Oblique Temporal Computed Tomography with Valsalva Maneuver.

BACKGROUND:  As indications for surgical Eustachian tube (ET) procedures have been expanded, it is essential to understand the anatomy of ET surroundings for safe ET interventions. METHODS:  We evaluated the peritubal region using oblique planes of temporal computed tomography (CT) with the Valsalva maneuver and classified the peritubal region between the osseous ET and the internal carotid artery (ICA) into 5 types: 1. bony prominence; 2. air cell; 3. absence of peritubal structures (3a. thick canal [>0.5 mm], 3b. thin canal [<0.5 mm], 3c. dehiscence). RESULTS:  Bony prominence and air cell types were observed in 41.0% (50/122 ears) and 13.1% (16/122 ears), respectively. The ICA was located directly medial to the osseous ET in 39.4% (48/114 ears), of which thick and thin canal types were found in 23.8% and 15.6%, respectively. Internal carotid artery canal wall dehiscence was observed in 8 ears (6.6%). The shortest perpendicular distance between the osseous ET and ICA was 1.6 (range: 0.4-4.9) mm and 2.7 (range: 1.3-5.8) mm in the bony prominence and air cell types, respectively. Osseous ET-ICA distances were 1.2 (range: 0.6-3.6) mm and 0.4 (range: 0.1-0.5) mm in thick and thin canal types, respectively. CONCLUSION:  Distinct peritubal structure types were observed on oblique CT planes with Vasalva maneuver. Bony prominence and air cell types provide a protective layer between the osseous ET and ICA. Imaging information on peritubal structures may help to better understand the anatomy of the ET pathway, leading to safe and accurate surgical approaches to the osseous ET.

The long-term efficacy and safety of balloon dilation eustachian tuboplasty combined with tympanostomy tube insertion for patients with otitis media with effusion: study protocol for a prospective randomized controlled trial.

BACKGROUND: Otitis media with effusion (OME) is a common disease in ear, nose, and throat clinics characterized by aural fullness and hearing loss and mainly caused by eustachian tube dysfunction (ETD). Tympanostomy tube insertion (TTI) is a conventional surgical treatment option that can alleviate symptoms but does not provide a definitive cure, and it is prone to recurrence. Balloon dilation eustachian tuboplasty (BDET) has become a novel procedure for the treatment of ETD, demonstrating significant potential in addressing the aforementioned limitations. However, it is not widely available in the clinic and few high-quality randomized clinical trials was conducted to investigate its long-term efficacy and security in OME. Therefore, the purpose of this study is to verify the efficacy of BDET combined with TTI for patients with OME and its prospects for providing a definitive cure. METHODS AND ANALYSIS: This is a prospective, parallel-group, single-blind, randomized controlled prospective trial. Totally 124 patients with OME will be randomized into either group A or B. Group A will receive conventional therapy (TTI) while group B will use BDET therapy in addition to TTI. Outcome assessments will take place at baseline and at the 3rd, 6th, 12th, and 24th months after surgery. The primary outcome is eustachian tube function, which will be measured by the eustachian tube dysfunction questionnaire (ETDQ-7) and eustachian tube score (ETS). The secondary outcomes include middle ear function, hearing situation, and quality of life, which will be measured by acoustic impedance measurement, pure-tone audiometry, and Chinese-version Chronic Ear Survey (CCES). The main analysis of change in the outcomes will use mixed-model with repeated measures (MMRM) analyses of variance (ANOVAs). DISCUSSION: This is the first prospective trial in Chinese populations that aims to validate the long-term efficacy and safety of BDET-combined TTI therapy in patients with OME. This parallel-group, single-blind, randomized controlled trial may provide an opportunity to decrease the recurrence rate of OME and explore a definitive cure for patients with OME. This trial's rigorous design enhances the reliability of the findings, ensuring a robust answer to the research question. In the future, the research team will further expand upon the clinical evidence and applications of the BDET combined therapy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2400079632. Registered on 8 January 2024, https://www.chictr.org.cn/bin/project/edit?pid=214452 .

The case for balloon eustachian tuboplasty in children.

PURPOSE OF REVIEW: Balloon dilation of the cartilaginous portion of the Eustachian tube has increasingly gained acceptance among otolaryngologists in the treatment of obstructive Eustachian tube dysfunction. There is however little data on the procedure performed in children. The purpose of this study is to review the recent developments regarding balloon dilation in pediatric patients. RECENT FINDINGS: Balloon dilation of the Eustachian tube is safe in pediatric patients. The effects of the procedure are durable during long term follow-up. Diagnosing obstructive dysfunction remains challenging. There is no single test or questionnaire for diagnosing the condition; instead a series of appropriate tests should be used. The pediatric Eustachian tube is very responsive to the effects of balloon dilation. While the treatment is effective, overtreatment can have unwanted results such as patulous symptoms. Reducing the time of dilation should therefore be considered. SUMMARY: Otolaryngologists performing the procedure should be familiar with the effects of balloon dilation on the pediatric Eustachian tube and consider altering the duration of dilation accordingly. Further studies are needed especially regarding patient selection, optimal age for dilation and balloon parameters for pediatrics (e.g. dimensions, inflation duration, inflation pressure).

[The effect of different degrees of Eustachian tube dysfunction on hearing threshold in patients with acquired primary middle ear cholesteatoma after balloon eustachian tuboplasty].

Objective:To investigate the changes in hearing threshold of the acquired primary cholesteatoma of the middle ear with different degrees of eustachian tube dysfunction after balloon eustachian tuboplasty. Methods:This retrospective study included forty cases with middle ear cholesteatoma and eustachian tube dysfunction who underwent open mastoidectomy + tympanoplasty + balloon eustachian tuboplasty were enrolled. All patients were admitted from November 2020 to April 2022. The preoperative eustachian tube score of 0-2 were defined as the lower group, and the scores of 3-5 were defined as the higher group. Pure tone audiometry was measured preoperatively and 1, 3, 6 and 12 months postoperatively. The average value of bone conduction threshold and air conduction threshold of 250-4 000 Hz were calculated, and the air-bone gap was calculated simultaneously. SPSS 25.0 was used for statistical analysis. P<0.05 was considered statistically significant. Results:In the lower group, the air conduction threshold and air-bone gap at 3 months postoperatively were significantly decreased in comparison with those preoperatively（P<0.05），as was the air-bone gap at 6 months postoperatively（P<0.05）. In the higher group, the air conduction threshold and air-bone gap were significantly decreased at 3, 6 and 12 months postoperatively（P<0.05）. Conclusion:The air conduction threshold and air-bone gap of patients with the acquired primary cholesteatoma of the middle ear and eustachian tube dysfunction were significantly decreased after eustachian tube balloon dilatation. Hearing improvement lasted longer in patients with slight eustachian tube dysfunction.

Effect of balloon dilatation among adult population with eustachian tube dysfunction: a systematic review.

PURPOSE: This study aimed to assess the efficacy and safety of ballon dilation of the eustachian tube (BDET) in adult population suffering from Eustachian tube dysfunction (ETD). METHODS: Following PRISMA criteria, a systematic review was conducted by searching PubMed, Cochrane, and Embase databases from January 2015 to March 2024. The primary outcomes included Eustachian Tube Score (ETS), tympanometry, and Valsalva maneuver. The quality of studies was assessed using the Quality in Prognostic Studies (QUIPS) instrument. RESULTS: Overall, 11 studies were incorporated into the systematic review: two RCTs, three prospective investigations, and six retrospective studies. The balloon dilation in all investigations was performed using either Spiggle & Theis or Acclarent catheters for balloon dilation. There was heterogeneity across studies examining the effect of BDET on persistent ETD in terms of patient selection, period of follow-up, administration of conservative or surgical therapies, and use of assessment methods. Overall, the treatment yielded alleviation of symptoms, which either exhibited stability over time or demonstrated further improvement after an average duration of follow-up. Moreover, the incidence of complications was categorized as low and resolving spontaneously. The majority of the studies exhibited a high risk of bias related to confounding variables, and consequently, the overall risk of bias across most studies was considered high. CONCLUSION: The findings suggest BDET holds promise for ETD treatment, reducing symptom severity with minimal complications. Nonetheless, there is a need for improved studies that adhere to established indications, methodologies, and outcomes to establish a more robust body of evidence.

Differential effects of mass-loading the eardrum and stiffening the middle ear on wideband absorbance.

The current work investigated the effects of mass-loading the eardrum on wideband absorbance in humans. A non-invasive approach to mass-loading the eardrum was utilized in which water was placed on the eardrum via ear canal access. The mass-loaded absorbance was compared to absorbance measured for two alternative middle ear states: normal and stiffened. To stiffen the ear, subjects pressurized the middle ear through either exsufflation or insufflation concurrent with Eustachian tube opening. Mass-loading the eardrum was hypothesized to reduce high-frequency absorbance, whereas pressurizing the middle ear was hypothesized to reduce low- to mid-frequency absorbance. Discriminant linear analysis classification was performed to evaluate the utility of absorbance in differentiating between conditions. Water on the eardrum reduced absorbance over the 0.7- to 6-kHz frequency range and increased absorbance at frequencies below approximately 0.5 kHz; these changes approximated the pattern of changes reported in both hearing thresholds and stapes motion upon mass-loading the eardrum. Pressurizing the middle ear reduced the absorbance over the 0.125- to 4-kHz frequency range. Several classification models based on the absorbance in two- or three-frequency bands had accuracy exceeding 88%.

Sound and Noise Sources in Sonotubometry: An Investigation of Eustachian Tube Assessment.

This research aims to enhance the understanding of the acoustic processes occurring during sonotubometry, a method used to assess the Eustachian tube (ET) function. Recent advancements in digital signal processing enable a more comprehensive data analysis. In this project, a silicone model of the ET was developed to systematically study the existing noise and sound sources. These measurements were then compared with recordings from human subjects. Three distinct 'noise sources' were identified, which can influence the assessment of the ET opening using transmission measurements of the imposed signal: sound leakage from the speaker, a clicking noise at the initiation of ET opening, and rumbling/swallowing noise. Through spectral analysis, it was also possible to ascertain the spectral and temporal occurrence of these sound and noise types. The silicone model exhibited remarkable similarity to the healthy human ET, making it a robust experimental model for investigating the acoustics of sonotubometry. The findings underscore the significance of delving deeper into the analysed sound, as the noise occurring during sonotubometry can be easily misconstrued as an actual ET opening. Particularly, careful consideration is warranted when evaluating data involving clicking and swallowing noise.

Anatomical Analysis of the Eustachian Tube in the Temporal Bone Through the Middle Fossa Window.

PURPOSE: This cadaveric anatomical study aimed to explore precise morphometric measurements of the eustachian tube (ET) and adjacent structures in the middle cranial fossa, focusing on identifying reliable surgical landmarks when traditional markers are compromised due to tumors or trauma. METHODS: Twenty-two temporal bones from 11 adult cadavers (mean age: 75.70 ± 13.75 yr, range: 40-90 yr; sex: 5 females and 6 males) were dissected bilaterally. Surgical tools, including an operation microscope, endoscope, and digital caliper, were used for meticulous measurements. Parameters such as ET dimensions, distances between key points, and relevant angles were quantified, ensuring precise anatomical data. RESULTS: ET width at the foramen spinosum (FS) level, the midline level, and the eustachian orifice level were measured as 2.18 ± 0.68, 2.42 ± 0.70, and 2.30 ± 0.74 mm, respectively. The distances from the zygomatic root (ZR) to FS, ET, superior semicircular canal (SSC), and internal carotid artery (ICA) were 29.61 ± 2.56, 23.28 ± 2.61, 26.53 ± 2.56, and 32.61 ± 3.69 mm, respectively. The angles between SSC-ZR-ICA and FS-ZR-ICA were measured as 36.57 ± 10.32 and 13.63 ± 3.72 degrees, respectively. No statistical difference was found between right-left or male-female measurements ( p > 0.05). CONCLUSION: The present study offers invaluable insights for neurotological surgeons performing middle fossa approaches. ET and ZR may serve as crucial reference points, enhancing surgical orientation and minimizing risks during complex procedures. These precise anatomical data may empower surgeons, ensuring safer and more confident middle cranial fossa operations, even in challenging clinical scenarios.

Assessing the usefulness of tubomanometry as a diagnostic tool in Eustachian tube dysfunction.

PURPOSE: This study aims to evaluate the validity and reliability of tubomanometry (TMM) in diagnosing obstructive Eustachian tube dysfunction (OETD) before balloon Eustachian tuboplasty (BET). METHODS: A prospective cohort study was conducted, involving 25 patients with sinonasal pathology, 75 patients with middle ear disease, and 25 healthy subjects, totaling 250 ears. All participants underwent comprehensive physical examinations, including TMM, nasal videoendoscopy, otoendoscopy, Valsalva maneuver (VM), tympanometry, and audiometry. Additionally, various scales such as ETDQ-7 and ETS-7 were employed. Tympanometry served as the gold standard for assessing OETD, and comparisons were made among the measures across the three groups. RESULTS: Among the 125 participants, 44.8% (n = 56) were female, and 55.2% (n = 69) were male, with ages ranging from 19 to 93 years (M = 48.5; SD = 15.6). In our study, VM demonstrated high sensitivity (86.3%) when tympanometry was considered the gold standard. Conversely, TMM, ETDQ-7, and ETS-7 exhibited high specificity, with ETDQ-7 showing the highest specificity (87.4%). Regarding TMM, all R values in patients within the middle ear disease group were pathological (R > 1). CONCLUSION: TMM has exhibited notable specificity as a diagnostic tool compared to tympanogram and VM. Nonetheless, the combination of TMM and ETDQ-7 has enabled us to conduct a diagnostic assessment with high sensitivity and specificity for chronic OETD diagnosis.

Interpretation of the nine-step test for Eustachian tube function should consider mastoid cavity volume.

INTRODUCTION: The modified nine-step test is a classical method for evaluating Eustachian tube function. However, clinical interpretation of the increased maximal difference in middle ear pressure (mdMEP) in the modified nine-step test is unknown. We hypothesised that the different reservoir effects of the mastoid cavity can bias the results of the modified nine-step test. METHODS: A total of 108 consecutive participants (216 ears) were retrospectively screened. Of these, 55 participants (82 ears) who met the inclusion/exclusion criteria were enrolled. The volumetric results of the mastoid cavity, parameters of the modified nine-step test (mdMEP, middle ear pressure, tympanic membrane compliance), and demographic data were analysed. RESULTS: A significant negative correlation was found between mdMEP and mastoid cavity volume (R = .467, p < .001). Ears with mdMEP >70 daPa showed poor pneumatization in the mastoid cavity, with volumes less than 3000 mm3 (10th percentile of all ears analysed). Ears with mastoid cavity volumes lower than the 25th percentile showed a significantly higher mdMEP (p < .001). Patients with mastoid cavity volumes higher than the 75th percentile were significantly younger (p < .001). Multivariate regression analysis for mdMEP showed a good fit (R = .854) using factors including middle ear pressure, admittance and, most importantly, the reciprocal of mastoid volume (Beta = 0.752, p < .001). CONCLUSIONS: The mdMEP, the main parameter of the modified nine-step test, was negatively correlated with the mastoid cavity volume. Therefore, the results of the modified nine-step test should be interpreted with consideration of mastoid cavity volume.

The presence of a submucous cleft palate in patients with isolated cleft lip and middle ear dysfunction.

PURPOSE: Recent studies have suggested that children with an isolated cleft lip (CL) are more likely to develop middle ear disease and eustachian tube dysfunction (ETD) compared to the general population. This may be related to abnormal palatal musculature or an undiagnosed submucosal cleft palate (SMCP). We aim to determine the prevalence of SMCP in patients with CL who exhibit ETD. MATERIALS AND METHODS: A retrospective chart review was performed for children with an isolated CL requiring tympanostomy tubes over a 20-year period at an academic tertiary care medical center. Demographic, clinical, and surgical data were collected. RESULTS: Three hundred twelve patients had an isolated CL, and 29 (9.3 %) children required tympanostomy tubes. Of those, nine (31 %) were found to have a SMCP (7 males, 6 Caucasian). The average age at CL repair was 3.94 ± 1.03 months, and the average age at tympanostomy tube placement was 13.68 ± 13.8 months. All nine patients had chronic otitis media, with four having mild conductive hearing loss and three having moderate conductive hearing loss. The SMCP was diagnosed at the time of CL diagnosis (4), after CL diagnosis with the diagnosis of chronic otitis media/ETD (2) and after a diagnosis of chronic otitis media/ETD. CONCLUSION: Middle ear disease or eustachian tube dysfunction in a patient with an isolated cleft lip should raise suspicion for an accompanying undiagnosed SMCP.

Efficacy of balloon Eustachian tuboplasty plus tympanostomy tube insertion in postirradiation otitis media with effusion.

OBJECTIVE: This study aimed to compare the efficacy of balloon Eustachian tuboplasty (BET) plus tympanostomy tube insertion (TTI) and simple TTI for postirradiation otitis media with effusion (OME) in patients with nasopharyngeal carcinoma. METHOD: This study included 36 patients (51 ears) with OME after the first radiotherapy course for nasopharyngeal carcinoma and categorized them into the BET + TTI and simple TTI groups. Effective rates, pure tone hearing threshold, Eustachian tube function score, and complication incidences were compared. RESULTS: The effective rates of the BET+TTI and TTI groups were 93.75 % and 75 %, respectively, with no statistically significant difference (P = 0.29). The pure tone hearing threshold examination at 9 months postoperatively revealed significantly lower mean air-pure tone and air-bone gap in both the BET + TTI and TTI groups than preoperatively. Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7) scores at every postoperative visit were significantly higher than preoperative scores in the two groups (all P < 0.05); ETDQ-7 score reduction in the BET + TTI group at 3, 9, and 12 months postoperatively was significantly higher than that in the TTI group. Otorrhea and recurrence both occurred in the BET+TTI and TTI groups, but the BET+TTI group demonstrated a lower incidence. CONCLUSION: BET + TTI is an effective treatment method for postirradiation OME.

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.

[Clinical features of congenitally enlarged bony portion of Eustachian tube].

Objective:To investigate the clinical features of patients with congenitally enlarged bony portions of the Eustachian tube（ET）. Methods:The medical history, physical examination, hearing test, temporal bone high resolution computed tomography（HRCT） of six patients（nine ears） with congenitally enlarged bony portion of the ET were retrospectively analyzed. Results:Four patients were men and two were women. The minimum, maximum, and average ages were 5, 21, and（14.7±6.4） years, respectively. Three malformations were bilateral and three were left-sided. Three ears had conductive hearing loss（average bone and air conduction thresholds were 13.7 dB and 71.3 dB）, three had mixed hearing loss（average bone and air conduction thresholds were 27.7 dB and 83.7 dB）, and one had extremely severe sensorineural hearing loss. The average maximum length and width of the enlarged bony ET on temporal bone HRCT were（22.61±2.94） mm and（6.50±2.33） mm, respectively. The enlargement was combined with an external auditory canal malformation in six ears, narrow tympanic cavity in six, tympanic antrum malformation in five, ossicular chain malformation in seven, cochlear malformation in six, helicotrema malformation in three, vestibule widening in two, semicircular canal malformation in three, vestibular window malformation in six, facial nerve abnormality in five, internal auditory meatus malformation in two, low middle cranial fossa in eight, and severe internal carotid artery malformation in one. Conclusion:Bony ET enlargement is a rare congenital middle ear malformation which could combined with other ear malformations. Patients can have no ET dysfunction but different patterns of hearing loss. The defect is usually found unintentionally during imaging, and the HRCT of temporal bone is significant.

Pneumatocoele after cochlear implantation with lateral petrosectomy: A minor complication?

OBJECTIVE: To illustrate the clinical features and management of pneumatocoele presenting with a trap-valve mechanism after cochlear implantation with lateral petrosectomy (LP) in comparison with literature. INTRODUCTION: Pneumatocoele is a rare complication of cochlear implant (CI) surgery, generally managed with conservative treatments. METHODS: We describe a progressively increasing pneumatocoele with a trap-valve mechanism occurring one year after CI with LP, successfully managed with revision surgery. Literature review was performed on this topic. RESULTS: Our case was the second ever reported in literature. It appeared consequently to forceful nose-blowing in a patient with refractory nasal polyposis. Unlike the pneumatocoeles reported after standard CI, we advised revision surgery as well as in the case of pneumatocoele after staged LP and CI. In both the patients subcutaneous air collection occurred as a late complication and an insufficient Eustachian tube closure was disclosed, which is considered a complication of LP itself. Surgical management was necessary in consideration of the risk of ascending infections associated with Eustachian tube patency in LP with CI. CONCLUSION: We consider surgical treatment mandatory in pneumatocoele after CI with LP, it is indeed the sentinel of the restoration of Eustachian tube patency and the potential prelude to major complications.