Using Geometric Morphometric Analysis of Magnetic Resonance Imaging to Assess the Anatomy of the Eustachian Tube in Children with and without Otitis Media.

Otitis media (OM) is among the most common of childhood illnesses. It has long been hypothesized that children under age two are predisposed to OM due to differences in the anatomy of the Eustachian tube (ET), including the angle of the ET. OM in later childhood is less common but does occur, begging the question, are there shape differences in the ET that persist underlying later occurrences of OM? To answer this question, a novel method, which applied geometric and morphometric shape analysis to landmarks obtained from MRI data, was used. MRI scans were performed on 16 children (5 control, 3 cOME, and 8 rAOM) between 2011 and 2015. Sixteen landmarks representing the shape of the ET, cranial base, and palate were analyzed. The results of a Procrustes ANOVA indicate that the shape of the ET varies significantly (p < 0.01) between the OM and control groups. The shape differences between the OM group and the control are a medial and low attachment site of the tensor veli palatini (TVP) muscle, a posterior and high torus tubarius, and an anteriorly projected palate. These results support previous findings that a relatively horizontal ET is associated with a predisposition for OM. This study used a novel approach to examine anatomical differences in children with and without OM. First, the data set is unique in that it includes MRI scans of children with a confirmed OM diagnosis. Second, the use of MRI scans in craniofacial anatomy OM research is novel and allows for the collection of soft tissue landmarks and the visualization of soft tissue structures. Third, geometric morphometric shape analysis is a statistical method that captures shape differences, offering a more universal picture of nuanced changes within the entire set of landmarks, in contrast to more traditional linear and angular measurements used in prior OM studies examining craniofacial anatomy.

CT Imaging of Eustachian Tube Balloon Dilation: Method Development on Cadaver Heads.

Objective: To develop a methodology for the measurement of balloon dilation (BD) effects on Eustachian Tube (ET) structure using Computerized Tomography (CT) images. Methods: The BD of the ET was performed on three cadaver heads (five ears) through the nasopharyngeal orifice. The axial CT images of the temporal bones were obtained before dilation, while an inflated balloon was in the lumen of ET, and after balloon removal in each ear. Utilizing Dicom images captured by the ImageJ software 3D volume viewer function, the anatomical landmark coordinates of the ET were matched with their pre- and post-dilation counterparts, and the longitudinal axis of the ET was captured with serial images. The histograms of the regions of interest (ROI) and three different lumen width and length measurements were obtained from captured images. The densities of air, tissue, and bone were determined with histograms as a baseline to determine the BD rate as a function of increased air in the lumen. Results: The small ROI box included the area of prominently dilated ET lumen after BD and best represented the visually obvious changes in the lumen, compared to the ROIs that extended the wider areas (longest and longer). Air density was the outcome measure for comparison with each corresponding baseline value. The average increase in air density in the small ROI was 64%, while the longest and long ROI boxes showed 44 and 56% increases, respectively. Conclusion: This study describes a method to image the ET and quantify the outcomes of BD of the ET using anatomical landmarks.

Tubomanometry in measurement of velopharyngeal closure: A pilot study.

Objective: To investigate the differences in velum closure pattern in people with and without a history of middle ear disease using intranasal pressure curves recorded with the tubomanometer, a Eustachian tube (ET) testing device. Study Design: Case control study. Setting: Tertiary referral center. Subjects and Methods: Tubomanometry nasopharyngeal pressure curves from 20 controls (Group 1) and 20 people with history of otitis media (OM) and possible ongoing ET dysfunction (ETD) (Group 2 or OM/ETD group) were compared. The variables included in the analysis were: (a) ratio of signal amplitude relative to the delivered nasal pressure (C2/delivered pressure x 10); (b) time (s) to achieve maximal signal amplitude (C2-C1); (c) duration of velum closure (s) and (d) plateau decay during the isometric contraction of the velum (C3-C2) and (e) swallow duration (s) (C4-C1). Statistical analysis was conducted using mixed models for the normalized values of individual characteristics. Results: Age, race and sex distribution in each group was as follows: 24 ± 8 years, 15 whites and 12 females in Group 1; 20 ± 10 years, 19 whites and 15 females in Group 2. Group 2 demonstrated a greater velopharyngeal pressure decay (p = .13), longer swallow duration (p = .10), and longer duration of velum closure (p = .14). Conclusion: This is the first study using tubomanometry to investigate differences in velopharyngeal closure between controls and individuals with OM/ETD. Although not statistically significant, our results showed that those with OM/ETD demonstrated a longer swallow and velum closure duration, and a higher degree of leakage during velum contraction compared to controls.

Dissecting eustachian tube dysfunction: From phenotypes to endotypes.

OBJECTIVE: A broad spectrum of complaints, symptoms and manifestations has been assigned to Eustachian tube (ET) dysfunction (ETD). While such presentations may manifest as ETD phenotypes, underlying mechanisms are defined as endotypes. Our goal is to develop a diagnostic approach to differentiate the endotypes and guide clinicians in the workup and selection of treatments targeting the mechanism of ETD. STUDY DESIGN: Retrospective. SETTING: Tertiary care. SUBJECTS AND METHODS: Children and adults with suspected ETD were evaluated with a thorough examination, otomicroscopy, otoendoscopy, trans-nasal videoendoscopy and testing of passive and active ET dilatory properties. Degree of weakness in soft palate elevation and ET orifice widening (muscular weakness, ETD-M), presence of inflammation (ETD-I) and/or adenoid tissue impinging and restricting the ET opening (ETD-R) were assessed with video-endoscopy. The Forced Response Test, Inflation-Deflation Test and Pressure Chamber Test were used as applicable to quantify the degree and type of difficulty (Stricture, ETD-S or adhesive, ETD-A) or ease (patulous or semi-patulous, ETD-P/SP) in opening the ET, and degree of active muscular strength/weakness (ETD-M) was measured. Ears with normal function (ETF-N) findings were also identified. RESULTS: Video-endoscopic and ETF test results were obtained for 71 ears of 40 subjects (22 males, 18 females; 38 white, 2 black), with an average age of 22.9 ± 16.5 years (min:6.2, max:64.1). Videoendoscopy (21, 13, 33, 16, 13, 0, 0 ETs) and ETF testing analysis (20, 24, 0, 38, 0, 3, 13 ears) were categorized as ETF-N and the ETD endotypes ETD-S, ETD-R, ETD-M, ETD-I, ETD-A, and ETD-P/SP, respectively. Some phenotypes had features consistent with more than one endotype. CONCLUSION: A systematic approach of examination and testing may differentiate the specific underlying mechanisms, lead to a treatment targeted to the ETD endotype and may establish novel ways to diagnose and treat ETD.

Change in Eustachian Tube Function With Balloon Dilation in Adults With Ventilation Tubes.

OBJECTIVE: Assess the changes in Eustachian tube (ET) function (ETF) with balloon dilation of Eustachian tube (BDET). STUDY DESIGN: Prospective cohort for repeated testing measures. SETTING: Clinical research center. PATIENTS: Eleven adults with at least one patent ventilation tube (VT) inserted for chronic ET dysfunction (ETD) and history of otitis media with effusion. INTERVENTIONS: Subjects with evidence of moderate to severe ETD on the side with a VT underwent unilateral BDET. MAIN OUTCOME MEASURES: Changes in ETF parameters after BDET measured by Forced Response Test (FRT), Inflation Deflation Test (IDT), and Pressure Chamber test. RESULTS: With the FRT at 11 ml/min, opening pressure (OP) decreased from 458 ±â€Š160 to 308 ±â€Š173 daPa and closing pressure (CP) from 115 ±â€Š83 to 72 ±â€Š81 daPa at the 3-month post-BDET visit. The IDT and Pressure Chamber test showed that the percentage of middle ear (ME) pressure gradient equilibrated with swallows improved from 28 ±â€Š34 to 53 ±â€Š5% for positive and from 20 ±â€Š28 to 38 ±â€Š43% for negative ME pressure. Images from the pre- and post-BDET functional CT scans did not show apparent changes in the anatomy. Comparisons of ETF test parameters pre- and post-BDET suggested that the ET was easier to open and stayed open longer after the procedure. However, during the limited duration of follow-up most subjects continued to have ETD, some requiring VT re-insertion after the study period. CONCLUSIONS: Adults with severe ETD may benefit from BDET, however ETD may not be completely resolved and patients may continue to need VTs.

Presentation and eustachian tube function test results in children evaluated at a specialty clinic.

OBJECTIVES/HYPOTHESIS: Interest in eustachian tube (ET) dysfunction (ETD) has increased with the recent Food and Drug Administration approval of a new device for balloon dilation of the ET (BDET) in adults. However, children have been receiving BDET treatment with ET-specific or sinus balloons around the world and off-label in the United States for years. It is important, therefore, to understand the manifestations of and methods to verify ETD in children. STUDY DESIGN: Retrospective cross-sectional study. METHODS: This is a retrospective study of clinical presentations and results of ET function (ETF) tests in children referred to the ETD clinic. An otorhinolaryngology exam, nasopharyngeal videoendoscopy of the ET orifices during swallow and maneuvers, and ETF tests, including inflation deflation, forced response test, and pressure chamber tests, were performed as applicable. RESULTS: Data for 30 children aged 6.2 to 17.3 years (mean = 12.9 ± 2.8 years) were analyzed. Of 60 ears, 19 (31.7%) had an intact tympanic membrane (TM), 16 (26.7%) had a patent and two had a blocked ventilation tube, and 23 (38.3%) had a TM perforation. Endoscopy of the nasopharynx revealed a large amount of secretions in 19/45 (42.2%); ET orifices and mucosal inflammation in 22/45 (48.8%); a large amount of adenoid tissue in the fossa of Rosenmuller was noted in 21/45 (46.7%). ETF tests revealed abnormal active function in 43/54 ears (79.6%) and abnormal passive function in 40/54 ears (74.1%). CONCLUSIONS: ETD in children is often associated with residual or regrowth of adenoids and inflammation. Caution should be taken assigning a uniform phenotype and treatment prior to thorough evaluation and testing. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1218-1228, 2019.

Eustachian Tube Function in Adults with Ventilation Tubes Inserted for Otitis Media with Effusion.

OBJECTIVE: To investigate the eustachian tube (ET) function (ETF) in adults with ventilation tube (VT) inserted for the treatment of chronic otitis media with effusion (COME). MATERIALS AND METHODS: A total of 17 subjects with at least one VT were enrolled. A detailed history was obtained, and risk factors were assessed with questionnaires. Examination including nasopharyngeal video endoscopy and ETF tests, the forced response test (FRT), inflation-deflation test (IDT), and nasal/nasopharyngeal maneuvers (such as sniffing and Valsalva, Toynbee, and the diver's maneuvers) were performed. RESULTS: Averages for FRT were 580±333 daPa, 382±251 daPa, and 138±192 daPa for opening pressure, steady-state pressure, and closing pressure, respectively. Most subjects demonstrated minimal or weak active function during the FRT and IDT. While nasopharyngeal maneuvers changed the nasal/nasopharyngeal pressures, they did not significantly change the middle-ear pressures. These results indicated that most subjects had severe obstructive ET dysfunction (ETD) with an ET lumen that required high pressure differences to open and poor active muscular function inadequate for luminal dilation. These results imply that while any treatment to widen the ET, such as balloon dilation of the ET, is not expected to change the voluntary active muscular function, it may reduce the tissue pressures and resistance, thus facilitating luminal opening both passively and actively. CONCLUSION: Most patients with VT inserted for the treatment of COME appear to have an abnormal ETF with difficulty in passively opening the ET and weak active muscular function. Management of such patients addressing only passive properties may not be sufficient for the resolution of ETD.

Quantitative representation of Eustachian tube component movements during swallowing.

OBJECTIVE: Describes a method of dynamic video-endoscopy of the Eustachian tube (ET) orifice at the nasopharynx to quantitatively represent ET component movements during swallowing using a graphic function and analyze their importance to its opening mechanics. METHODS: This was a pilot study of relational event capture using a polar coordinate system applied to trans-nasal video-endoscopic recordings of the ET during 3 swallows in 5 adults. After topical anesthesia of the nose, a 45° telescope was introduced unilaterally and focused on the ipsilateral ET orifice. For each recording, consecutive still-frame images were analyzed by identifying 4 fixed-point locators; the luminal apex, lateral and medial walls and the torus. A frame-normal, horizontal line was constructed through the apex and, then, the medial angles defined at the intersection of the horizontal line and the lines from apex to each point locator were measured. The magnitudes of these angles were plotted as a function of time (i.e. successive frames) for each swallow. RESULTS: The resulting graphs captured the "in plane" relational movements for the locator points during a swallow. Complex interactions among the ET components were resolvable and the patterns were reproducible across swallows. Individual peculiarities observable on review of the corresponding "movies" such as double-swallows, delayed swallows and ET luminal constriction were easily identified in the graphic representation. CONCLUSION: This methodology is potentially useful for summary presentations of the ET mechanics of individual patients and for quantifying differences in those mechanics between groups defined by their history of middle-ear disease.

Accuracy of the ETDQ-7 for Identifying Persons with Eustachian Tube Dysfunction.

Objective To compare the accuracy of the Eustachian Tube Dysfunction Questionnaire (ETDQ-7) in identifying people with eustachian tube (ET) dysfunction based on symptoms and an objective ET function test. Study Design Cross-sectional study. ObjSettingective Tertiary referral center. Subjects and Methods Fifty-five subjects with and without symptoms suggestive of ET dysfunction completed the ETDQ-7 and had their ET function evaluated by the percentage of middle ear pressure equilibrated after 5 swallows (PEq5) either during a pressure chamber test (intact tympanic membranes) or by the inflation-deflation test (nonintact tympanic membranes). ETDQ-7 score ≥14.5 and PEq5 <60% were used to define ET dysfunction, and sensitivity, specificity, and receiver operating characteristic curves were used to assess the level of association between ETDQ-7 scores and PEq5. Results Twenty-five asymptomatic subjects (group 1 = 15 females, 15 white; mean ± SD age, 32 ± 12.8 years) and 30 subjects with ET dysfunction symptoms (group 2 = 17 females, 25 white; age, 27 ± 16.3 years) were included in the analysis. ETDQ-7 sensitivity and specificity regarding correct group assignment were 70% and 100%, respectively, and with respect to predicting PEq5<60%, 54% and 78%. An area under the curve (AUC) of 0.68 (95% CI, 0.53-0.83) at the participant level and 0.64 (95% CI, 0.50-0.77) at the ear level indicated a moderate level of association that was lower, though not statistically significant, for nonintact tympanic membranes (AUC = 0.63 at the participant level and AUC = 0.49 at the ear level). Conclusion The ETDQ-7 score had a higher correlation with the ET dysfunction symptoms than with an objective measure of ET function.

A Novel Imaging Method for the Cartilaginous Eustachian Tube Lumen: Computerized Tomography During the Forced Response Test.

OBJECTIVES: In vivo imaging of the open cartilaginous Eustachian tube (ET) lumen by computed tomography (CT) scan during ET function (ETF) testing to establish new methodology. METHODS: Five adults underwent unilateral ETF testing of an ear with a nonintact tympanic membrane using the forced response test (FRT) to measure the opening pressure (PO), steady state pressure (PS), and flow conductance (CS). Then at baseline and during the PS phase of the FRT, a temporal-bone CT scan with continuous 0.625 mm thickness was obtained. Multiplanar oblique reformats along the axis of the ET were created, and point value and region of interest (ROI) Hounsfield unit measurements were recorded from the location of the ET lumen. RESULTS: At the FRT flow rate of 11 ml/min, the average PO, PS, and CS were 370.5 daPa, 119.6 daPa, and 0.16 ml/min/daPa, respectively. For flow rates of 23 and 46 ml/min, these values were 236.2, 204.2, 0.12 and 385.5, 321.1, 0.18, respectively. Although areas with lower attenuation were suggestive of air density, a distinct air-filled cartilaginous ET lumen could not be confirmed. CONCLUSIONS: While the current imaging parameters failed to resolve the air-soft tissue interface throughout the open cartilaginous ET, further advances in imaging may obviate this limitation.

Panel 2: Anatomy (Eustachian Tube, Middle Ear, and Mastoid-Anatomy, Physiology, Pathophysiology, and Pathogenesis).

Objective In this report, we review the recent literature (ie, past 4 years) to identify advances in our understanding of the middle ear-mastoid-eustachian tube system. We use this review to determine whether the short-term goals elaborated in the last report were achieved, and we propose updated goals to guide future otitis media research. Data Sources PubMed, Web of Science, Medline. Review Methods The panel topic was subdivided, and each contributor performed a literature search within the given time frame. The keywords searched included middle ear, eustachian tube, and mastoid for their intersection with anatomy, physiology, pathophysiology, and pathology. Preliminary reports from each panel member were consolidated and discussed when the panel met on June 11, 2015. At that meeting, the progress was evaluated and new short-term goals proposed. Conclusions Progress was made on 13 of the 20 short-term goals proposed in 2011. Significant advances were made in the characterization of middle ear gas exchange pathways, modeling eustachian tube function, and preliminary testing of treatments for eustachian tube dysfunction. Implications for Practice In the future, imaging technologies should be developed to noninvasively assess middle ear/eustachian tube structure and physiology with respect to their role in otitis media pathogenesis. The new data derived from these structure/function experiments should be integrated into computational models that can then be used to develop specific hypotheses concerning otitis media pathogenesis and persistence. Finally, rigorous studies on medical or surgical treatments for eustachian tube dysfunction should be undertaken.

Histamine Applied Topically to the Nasal Mucosa Increases the Transmucosal Nitrous Oxide Exchange for the Middle Ear.

OBJECTIVE: Determine if the middle ear transmucosal nitrous oxide (N2O) exchange rate is affected by nasal inflammation caused by topical application of histamine. METHODS: In a randomized, double-blind, crossover study, 20 adults were challenged intranasally with histamine (5 mg) and placebo on separate occasions. At each session, the subjects were fitted with a non-rebreathing mask and breathed room air for 20 minutes, 50% N2O:50% O2 for 20 minutes, and 100% O2 for 10 minutes. Throughout, heart rate, blood pressure, and blood O2 saturation were monitored, and bilateral middle ear pressure was recorded by tympanometry every minute. The primary outcome measure was the slope of the middle ear pressure-time function for the 50% N2O:50% O2 breathing period, which is a measure of the transmucosal N2O exchange-constant. The effects of challenge substance, session, and period on the measured vital signs and of treatment, session, ear disease history, and test ear on the pressure-time slopes were evaluated using repeated measures ANOVAs. RESULTS: The post-challenge total symptom score and the slope of the middle ear pressure-time function were greater after histamine when compared to placebo challenge. Of the signs, only heart rate was affected, responding to challenge substance and study period. CONCLUSION: The transmucosal N2O exchange rate for the middle ear is increased during inflammation caused by nasal histamine exposure.

Diagnostic accuracy of tubomanometry R value in detecting the Eustachian tube pressure equalizing function.

Tubomanometry is a relatively novel Eustachian tube (ET) function testing method. A number of recent studies have utilized the R value of Tubomanometry as the main objective measure in reporting their outcome in balloon dilation of ET. There is, however, a lack of evidence concerning the reliability or validity of Tubomanometry measurements. The objectives of this study are to determine the accuracy of Tubomanometry for detecting ET opening as compared to tympanometry and determine its usefulness as a measure of ET function. Healthy subjects between ages 8 and 76 years with an intact tympanic membrane and no middle ear (ME) effusion were prospectively tested. Primary outcomes were the ET opening as determined by the Tubomanometry R value and the increase in ME pressure with tympanometry-measured in relation to a swallow at a nasopharyngeal pressure of 300 daPa. The accuracy of the tubomanometry R value for identifying a successful ET opening was made in reference to the change of ME pressure. A total of 280 measurements were available from 258 ears in 137 subjects. The presence of tubomanometry R value showed high sensitivity of detecting ET opening for the criteria of >5 daPa ME pressure increase (187/202) but low specificity for detecting ET non-opening (34/78). The R value criterion described in the original manuscripts on Tubomanometry is sensitive but not specific for ET opening. The need for validation of the tubomanometry test obviates its use as the main objective outcome measure for the balloon dilation of ET procedure.

Correlations between videoendoscopy and sonotubometry of eustachian tube opening during a swallow.

OBJECTIVES/HYPOTHESIS: Describe the relationship between the magnitude of eustachian tube (ET) dilation during swallowing observed on transnasal videoendoscopy and quantified by sonotubometry. STUDY DESIGN: Descriptive observational study. METHODS: Simultaneous transnasal videoendoscopic and sonotubometric recordings were done on 33 adults with no middle ear disease. Briefly, microphones were placed in the ear canals, a 45° telescope introduced through one side of the nose to visualize and record ipsilateral ET movements, and the probe from a sound generator placed in the opposite nostril. At a generated nasopharyngeal sound level, ET movements and ipsilateral microphone signals were continuously recorded while the subject performed a series of three swallows. For each swallow, relational movements among ET structures observed on video recordings and characteristics of the sonotubometry signal envelope at the ear canal were quantified at three times: swallow onset (T1), maximum soft-palate elevation (T2), and maximum ET luminal dilation (T3). RESULTS: A total of 99 swallows were analyzed. The average medial rotation of the ET cartilage and lateral wall over the T1-T2 interval were -32.7 ± 14.9° and 7.2 ± 25.1°, and over the T2-T3 interval were 4.6 ± 7.7° and 6.2 ± 14.6°, respectively. The transtubal sound transmission during a swallow peaked at an amplitude of 30.5 ± 35.7 mV during the 572.5 ± 292.6 ms of elevated sound-pressure time. Correlational analysis documented significant linear associations between the relational measures of ET component movements from videoendoscopy and the signal envelope measures from sonotubometry. CONCLUSIONS: There is a direct linear relationship between the degree of ET luminal dilation visualized on videoendoscopy and represented in the sonotubometry signal envelope. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2778-2784, 2016.

Oxymetazoline Applied Topically to the Nasal Mucosa Decreases Trans-Mucosal Nitrous Oxide Exchange for the Middle Ear.

OBJECTIVE: Determine if the middle ear (ME) trans-mucosal nitrous oxide (N2O) gas exchange rate can be pharmacologically modulated by the nasal application of a vasoconstrictor. METHODS: In a randomized, double-blind, crossover study, 20 adults received a nasal spray challenge containing either oxymetazoline or saline (placebo). At each session, subjects were fitted with a non-rebreathing mask and breathed room air for 20 minutes, 50% N2O:50% O2 for 20 minutes, and 100% O2 for 10 minutes. Throughout, heart rate, blood pressure (BP), and blood O2 saturation were monitored, and bilateral ME pressure was recorded by tympanometry every minute. The primary outcome measure was the slope of the ME pressure-time function for the experimental period, a direct measure of the transMEM N2O exchange constant. The effects of treatment, session, and period on the measured vital signs and of treatment, session, disease history, and ear on the ME pressure-time slopes were evaluated for statistical significance using repeated measures ANOVAs. RESULTS: The analysis documented a significant effect of period on O2 saturation (N2O > room air, P = .03) and of treatment on blood pressure (oxymetazoline > placebo, P < .02) and the ME pressure-time slope (placebo > oxymetazoline, P = .05). CONCLUSION: The exchange rate across the ME mucosa of inert gases can be decreased by topical treatment of the nasal mucosa with oxymetazoline.

Eustachian Tube Function in 6-Year-Old Children with and without a History of Middle Ear Disease.

OBJECTIVE: To test the hypothesis that eustachian tube opening efficiency, measured as the fractional gradient equilibrated (FGE), is lower in 6-year-old children with no middle ear disease but a well-documented history of recurrent acute otitis media, as compared with children with a negative disease history (control). STUDY DESIGN: Cross-sectional study. SETTING: Tertiary care pediatric hospital. SUBJECTS AND METHODS: Bilateral eustachian tube function was evaluated in 44 healthy 6-year-old children (19 boys, 29 white). None had middle ear disease at the time of testing, but 23 had a history of recurrent acute otitis media. Twenty-one had no significant past otitis media. Eustachian tube function was measured with a pressure chamber protocol that established negative middle ear gauge pressures (referenced to the chamber pressure) and recorded that pressure before and after a swallow. FGE was calculated as the change in middle ear gauge pressure with swallowing divided by the preswallow pressure. Between-group comparisons of the preswallow pressures and FGEs were made with a 2-tailed Student's t test. RESULTS: FGE was independent of the preswallow middle ear gauge pressure. For the 39 and 44 evaluable ears in the control and recurrent acute otitis media groups, the mean preswallow pressures were -194 daPa (95% confidence interval [95% CI] = -211 to -177) versus -203 (95% CI = -216 to -190; P > .40), and FGEs were 0.32 (95% CI = 0.21-0.43) vs 0.16 (95% CI = 0.08-0.24; P = .016), respectively. CONCLUSION: In children with past recurrent acute otitis media, residual eustachian tube opening inefficiency is maintained after they have "outgrown" their middle ear disease.

Oral pseudoephedrine decreases the rate of transmucosal nitrous oxide exchange for the middle ear.

OBJECTIVES/HYPOTHESIS: Determine if oral treatment with a vasoconstrictor decreases the blood to middle ear exchange rate of the perfusion-limited gas, nitrous oxide (N2O). STUDY DESIGN: Randomized, double-blind, crossover study. METHODS: Ten adult subjects with and 10 without past middle ear disease completed paired experimental sessions, identical except for oral treatment with either pseudoephedrine hydrochloride or lactose placebo. At each session, subjects were fitted with a nonrebreathing mask and breathed room air for 20 minutes (acclimation period), 50% N2O:50% O2 for 20 minutes (experimental period), and 100% O2 for 10 minutes (recovery period). Throughout, heart rate, blood pressure, and O2 saturation were monitored, and bilateral middle ear pressures were recorded by tympanometry every minute. The primary outcome was the slope of the middle ear pressure-time function for the experimental period, which estimates the volume N2O exchange rate. Using repeated measures analysis of variance, the effects of group (disease history), treatment (active vs. placebo), and period (1 vs. 2) on the recorded vital signs, and of group, treatment, and ear (left/right) on the middle ear pressure-time slope were evaluated for statistical significance. RESULTS: Statistically significant effects of period on O2 saturation (period 2 > period 1) and of treatment on heart rate (active > placebo) were documented. Only treatment was statistically significant for the middle ear pressure-time slope, with a shallower slope characterizing the active treatment session. CONCLUSIONS: The volume exchange rate across the middle ear mucosa of perfusion-limited gases can be modulated pharmacologically. Theoretically, similar drugs can be used to reduce the requisite eustachian tube opening efficiency for adequate middle ear pressure regulation. LEVEL OF EVIDENCE: 1b.

Quantitative description of eustachian tube movements during swallowing as visualized by transnasal videoendoscopy.

IMPORTANCE: Eustachian tube (ET) dysfunction predisposes ears to otitis media, tympanic membrane retraction, retraction pocket and perforation, or cholesteatoma. OBJECTIVE: To develop a method to quantitatively measure the eustachian tube (ET) component movements and their interactions captured by transnasal videoendoscopy of the ET during swallowing. DESIGN, SETTING, AND PARTICIPANTS: A blinded analysis of ET mechanics in 33 adults, aged 18 to 54 years, with no middle ear disease at present but without (group 1 [n = 16]) or with (group 2 [n = 17]) history of disease, conducted at a clinical research laboratory. INTERVENTIONS: Videoendoscopy of the ET orifice at the nasopharynx. MAIN OUTCOMES AND MEASURES: Eustachian tube component translations and structural interactions during a swallow and the between-group differences in those variables. After topical anesthesia of the nose, a 45° telescope was introduced unilaterally and focused on the ipsilateral ET orifice. A video recording of ET component movements was made during 3 swallows. Swallow and ET opening durations and times to selected events were calculated. Images at 3 time points were analyzed by measuring the apex angle, the medial-lateral luminal width, and the medial angles between a frame-normal horizontal line through the apex and fixed points on the torus and medial and lateral luminal walls. Linear and angular variables during a swallow were expressed as change from baseline. RESULTS: Luminal opening was driven by soft palate elevation-related medial rotation of the torus and medial wall, coupled with lateral wall fixedness. The magnitude of the change from baseline for most variables was statistically greater than 0. Swallow time, palatal elevation time, time interval between maximum palatal elevation, and maximum eustachian tube opening time were not different between groups 1 and 2. Opening time was longer (mean [SD], 0.49 [0.28] vs 0.67 [0.51] seconds; P = .03) in group 2. Higher magnitude of torus rotation (mean [SD], 36.05° [12.96°] vs 27.72° [9.45°]; P = .002) with maximum soft palate elevation in group 1 resulted in greater degree of eustachian tube orifice widening (mean [SD], 0.34% [0.47%] vs -0.02% [0.49%]; P = .001) compared with the resting position in that group. CONCLUSIONS AND RELEVANCE: This methodology has application in developing quantitative descriptions of ET mechanics in groups of persons without and with history or suspected ET dysfunction. A lesser degree of soft palate elevation during swallow that derives the ET medial lamina rotation and widening of the ET orifice may be associated with poor ET function and higher risk for otitis media. Videoendoscopic evaluation of the ET orifice may assist in diagnosing presence and mechanism of ET dysfunction.