Experimental paralysis of tensor veli palatini muscle

Eustachian Tube Function Symptoms in Palatal Surgeries for OSA: 3-Month Postoperative Analysis

OBJECTIVES

To assess the influence of different soft palate surgeries for obstructive sleep apnea (OSA) on eustachian tube function symptoms, considering various potential factors.

METHODS

A prospective, cohort study was conducted on patients who underwent isolated palatal surgeries for OSA at a single academic medical center between 2017 and 2022. Eustachian Tube Dysfunction Questionnaire (ETDQ-7) were assessed at baseline, 1-month, 2-month, and 3-month time points. Patients with retropalatal obstruction underwent tailored surgeries: anterior palatoplasty (AP), expansion sphincter palatoplasty (ESP), or barbed palatoplasty (BP). Baseline OSA severity between baseline and follow-up time points were also examined.

RESULTS

In this study, 96 patients with OSA were enrolled and allocated to three surgical groups: AP (n = 30), ESP (n = 32), and BP (n = 34). The mean age was 44.3 ± 10.2 years, with 86% male participants. No significant differences were found between the groups in terms of age, sex, and BMI. A two-way repeated measures ANOVA revealed a significant main effect of time on ETDQ-7 scores (p < 0.001), but no significant main effect of groups (p = 0.109) or interaction between time and groups (p = 0.082). Subgroup analysis showed a significant interaction for the 3-month change in ETDQ-7 scores by OSA severity (p = 0.046). In post hoc analysis, the BP group exhibited a higher mean ETDQ-7 score compared with the AP group at the 3-month follow-up.

CONCLUSION

This study highlights the importance of considering individual patient factors, such as OSA severity and eustachian tube function symptoms, when selecting the most appropriate surgical treatment to optimize outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2471-2477, 2024.

Evaluation of Eustachian Tube Function in Cases of Chronic Otitis Media by Dynamic Slow Motion Videoendoscopy and Impedance Audiometry

Eustachian tube (ET) dysfunction is known to be a cause for various middle ear diseases. Dynamic slow motion videoendoscopy (DSVE) and impedance audiometry (IA) can both be employed to evaluate ET dysfunction. To assess the role of DSVE and IA for diagnosing ET dysfunction in cases of middle ear disorders. It is a prospective case control study. 102 ears with chronic otitis media were taken as cases and 102 healthy ears as controls. IA and DSVE were performed to assess ET function in both the groups. Sensitivity/ specificity of both the diagnostic tests were evaluated in case and control groups. Out of 102 ET of case group exposed to both tests, 87 were found to have ET dysfunction by DSVE and 80 by IA. Among 102 ET of control group 78 were identified as normal by DSVE while 87 by IA. On applying chi square test in both these groups, the associations were significant. (p value < 0.0001). Patients with grade 2B or higher on DSVE endoscopy had abnormal IA findings, indicating that higher the grade on DSVE, higher the chance of abnormal IA. DSVE and IA are potentially useful tools in evaluation of cases of COM and which provide information regarding functional and pathological factors responsible for ET dysfunction.

Tensor Veli Palatinopexy as a Novel Treatment for Eustachian Tube Dysfunction: A Cadaveric Feasibility Study

OBJECTIVE

To demonstrate the feasibility of a novel procedure whereby a suture is placed transorally in the tensor veli palatini muscle to tighten it, thereby dilating the cartilaginous portion of the eustachian tube (ET).

STUDY DESIGN

The study design was a prospective cadaveric experiment to examine the feasibility of a novel treatment for ET dysfunction.

SETTING

Academic medical center in a research-oriented operating room with intraoperative computed tomography (CT) capabilities.

METHODS

Seven fresh-frozen cadaver heads were obtained, each of which was thawed for 36 hours prior to use. The preprocedural volumes of the cartilaginous ET were measured by filling the ET with an iodine-containing radiocontrast agent via the nasopharynx and then obtaining CT images. Submucosal flaps in the soft palate were raised, and sutures were placed in the tensor veli palatini bilaterally to increase tension. After completion of the procedure, contrast placement and CT imaging were repeated. Three-dimensional models of the ETs were created, and the volumes were measured and compared.

RESULTS

Of the 14 ETs evaluated, 13 showed an increase in postprocedure volume. On average, postprocedure volumes showed a 57% increase from preprocedure volumes (mean relative change, 57.1%; P = .013).

CONCLUSION

Placement of a tension-holding suture in the tensor veli palatini muscle can reliably dilate the cartilaginous portion of the ET. Such a procedure may be useful in the treatment of ET dysfunction.

Multi-scale modeling of an upper respiratory airway: Effect of mucosal adhesion on Eustachian tube function in young children

BACKGROUND

The Eustachian tube is a collapsible upper respiratory airway that is periodically opened to maintain a healthy middle ear. Young children, <10 years old, exhibit reduced Eustachian tube opening efficiency and are at risk for developing middle ear infections. Although these infections increase mucosal adhesion, it is not known how adhesion forces alters the biomechanics of Eustachian tube opening in young children. This study uses computational techniques to investigate how increased mucosal adhesion alters Eustachian tube function in young children.

METHODS

Multi-scale finite element models were used to simulate the muscle-assisted opening of the Eustachian tube in healthy adults and young children. Airflow during opening was quantified as a function of adhesion strength, muscle forces and tissue mechanics.

FINDINGS

Although Eustachian tube function was sensitive to increased mucosal adhesion in both adults and children, young children developed Eustachian tube dysfunction at significantly lower values of mucosal adhesion. Specifically, the critical adhesion value was 2 orders of magnitude lower in young children as compared to healthy adults. Although increased adhesion did not alter the sensitivity of Eustachian tube function to tensor and levator veli palatini muscles forces, increased adhesion in young children did reduced the sensitivity of Eustachian tube function to changes in cartilage and mucosal tissue stiffness.

INTERPRETATIONS

These results indicate that increased mucosal adhesion can significantly alter the biomechanical mechanisms of Eustachian tube function in young children and that clinical assessment of adhesion levels may be important in therapy selection.

Effect of Chlorpheniramine on Airway Physiology and Symptoms during Natural Pollen Exposure

Previous studies have documented the changes in airway physiology which accompany natural pollen exposure. This study was designed to determine the effect of chlorpheniramine (8 mg b.i.d.) on seasonal changes in airway physiology and symptoms. Pollen counts, eustachian tube (ET) function, nasal resistance, mucociliary transport, and nasal symptoms were assessed weekly before, during, and after ragweed pollen season in 15 chlorpheniramine-treated and 15 placebo-treated allergic rhinitis (AR) subjects in a double-blind protocol and in 10 untreated control (non-AR) subjects. In placebo-treated AR subjects, the degree of congestion, rhinorrhea, sneezing, ET dysfunction, and nasal obstruction closely tracked pollen counts. However, symptoms, ET obstruction, and nasal obstruction persisted well beyond the temporal peak in pollen counts. There were no changes in mucociliary transport or pulmonary function during pollen exposure. Compared to placebo, chlorpheniramine-treated subjects manifested significantly less (p < .05) seasonal sneezing and rhinorrhea, but similar degrees of nasal congestion, ET dysfunction, and nasal obstruction. Pollen-related changes in nasal physiology and symptoms were not detected in the non-AR subjects. These data document that chlorpheniramine significantly attenuated the seasonal increases in rhinorrhea and sneezing, but did not lessen the concommitant physiologic alterations or the increase in nasal congestion.

A formal description of middle ear pressure-regulation

INTRODUCTION

Middle ear (ME) pressure-regulation (MEPR) is a homeostatic mechanism that maintains the ME-environment pressure-gradient (MEEPG) within a range optimized for "normal" hearing.

OBJECTIVE

Describe MEPR using equations applicable to passive, inter-compartmental gas-exchange and determine if the predictions of that description include the increasing ME pressure observed under certain conditions and interpreted by some as evidencing gas-production by the ME mucosa.

METHODS

MEPR was modeled as the combined effect of passive gas-exchanges between the ME and: perilymph via the round window membrane, the ambient environment via the tympanic membrane, and the local blood via the ME mucosa and of gas flow between the ME and nasopharynx during Eustachian tube openings. The first 3 of these exchanges are described at the species level using the Fick's diffusion equation and the last as a bulk gas transfer governed by Poiseuille's equation. The model structure is a time-iteration of the equation: P^ME_{g(t=(i+1)Δt)} = ∑^s(P^ME_s(t=iΔt)+(1/(β^ME_sV^ME)∑^P(Қ^P_s(P^C_s(t=(iΔt)-P^ME_s(t=(iΔt))). There, P^ME_g(t=iΔt) and P^ME_s(t=iΔt) are the ME total and species-pressures at the indexed times, P^C_s(t=iΔt) is the species-pressure for each exchange-compartment, β^ME_sV^ME is the product of the ME species-capacitance and volume, Қ^P_s is the pathway species-conductance, and ∑^S and ∑^P are operators for summing the expression over all species or exchange pathways.

RESULTS

When calibrated to known values, the model predicts the empirically measured ME species-pressures and the observed time-trajectories for total ME pressure and the MEEPG under a wide variety of physiologic, pathologic and non-physiologic conditions.

CONCLUSIONS

Passive inter-compartmental gas exchange is sole and sufficient to describe MEPR.

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.

Multi-scale finite element modeling of Eustachian tube function: influence of mucosal adhesion

The inability to open the collapsible Eustachian tube (ET) leads to the development of chronic Otitis Media (OM). Although mucosal inflammation during OM leads to increased mucin gene expression and elevated adhesion forces within the ET lumen, it is not known how changes in mucosal adhesion alter the biomechanical mechanisms of ET function. In this study, we developed a novel multi-scale finite element model of ET function in adults that utilizes adhesion spring elements to simulate changes in mucosal adhesion. Models were created for six adult subjects, and dynamic patterns in muscle contraction were used to simulate the wave-like opening of the ET that occurs during swallowing. Results indicate that ET opening is highly sensitive to the level of mucosal adhesion and that exceeding a critical value of adhesion leads to rapid ET dysfunction. Parameter variation studies and sensitivity analysis indicate that increased mucosal adhesion alters the relative importance of several tissue biomechanical properties. For example, increases in mucosal adhesion reduced the sensitivity of ET function to tensor veli palatini muscle forces but did not alter the insensitivity of ET function to levator veli palatini muscle forces. Interestingly, although changes in cartilage stiffness did not significantly influence ET opening under low adhesion conditions, ET opening was highly sensitive to changes in cartilage stiffness under high adhesion conditions. Therefore, our multi-scale computational models indicate that changes in mucosal adhesion as would occur during inflammatory OM alter the biomechanical mechanisms of ET function. Copyright © 2016 John Wiley & Sons, Ltd.

A longitudinal evaluation of hearing and ventilation tube insertion in patients with primary ciliary dyskinesia

INTRODUCTION

Primary ciliary dyskinesia (PCD) is an autosomal recessive genetic disease, which primarily manifests with oto-sino-pulmonary symptoms. Otitis media with effusion (OME) is common from early childhood. The existing literature on OME management in PCD is conflicting. The goals of the present study were firstly to evaluate the long-term hearing in PCD patients and secondly to determine the influence of ventilation tube (VT) insertion on hearing and postoperative otorrhoea.

METHODS

A longitudinal retrospective study extracting the hearing level (pure tone average (0.5, 1, 2, 4 kHz, PTA)) and tympanometry from the medical records. Furthermore, the patient files were reviewed for VT insertion and postoperative otorrhoea. Postoperative otorrhoea was defined prolonged when it lasted for four weeks or longer.

RESULTS

Fifty-seven patients were identified in a 30-year period, age 2-72 years, and 278 audiometries were evaluated. The median number of audiometries per patient was 3 (range 1-29) and the median follow-up was 60 months (range 0-351 months). The mean PTA was 34 dB HL in patients below six years of age and improved significantly (p < 0.0001) with age. VT insertion improved hearing; however, 48% of patients with VT insertion experienced prolonged otorrhoea.

CONCLUSION

In this study of PCD patients the hearing improved as a function of age as well as following VT insertion. However, VT insertion was also associated with prolonged otorrhoea.

Successful Treatment of Autophonia with Botulinum Toxin: Case Report

Objectives:

We sought to treat autophonia due to a patulous eustachian tube using botulinum toxin.

Methods:

Because we assumed that the patulous eustachian tube was caused by abnormal activity of paratubal muscles (tensor and levator veli palatini muscles and salpingopharyngeus muscle), paralysis was performed via injection of botulinum toxin type A in a 45-year-old female professional musician who had had chronic unilateral autophonia for 20 years. In addition to a patient interview, an endoscopic examination of the nasopharynx (posterior rhinoscopy), ear microscopy, and impedance audiometry were performed to verify the diagnosis and the outcome after treatment.

Results:

The autophonia disappeared 1 week after treatment. Normalized tympanic ventilation was verified by impedance audiometry after 8 weeks. The period of symptom relief was 9 months.

Conclusions:

The administration of botulinum toxin type A provides a new option in the treatment of patulous eustachian tube. The reliability of this method and the effect of repeated injections remains to be proved in future studies.

The role of the tensor veli palatini muscle in the development of cleft palate-associated middle ear problems

Objective

Otitis media with effusion is common in infants with an unrepaired cleft palate. Although its prevalence is reduced after cleft surgery, many children continue to suffer from middle ear problems during childhood. While the tensor veli palatini muscle is thought to be involved in middle ear ventilation, evidence about its exact anatomy, function, and role in cleft palate surgery is limited.

This study aimed to perform a thorough review of the literature on (1) the role of the tensor veli palatini muscle in the Eustachian tube opening and middle ear ventilation, (2) anatomical anomalies in cleft palate infants related to middle ear disease, and (3) their implications for surgical techniques used in cleft palate repair.

Materials and methods

A literature search on the MEDLINE database was performed using a combination of the keywords “tensor veli palatini muscle,” “Eustachian tube,” “otitis media with effusion,” and “cleft palate.”

Results

Several studies confirm the important role of the tensor veli palatini muscle in the Eustachian tube opening mechanism. Maintaining the integrity of the tensor veli palatini muscle during cleft palate surgery seems to improve long-term otological outcome. However, anatomical variations in cleft palate children may alter the effect of the tensor veli palatini muscle on the Eustachian tube’s dilatation mechanism.

Conclusion

More research is warranted to clarify the role of the tensor veli palatini muscle in cleft palate-associated Eustachian tube dysfunction and development of middle ear problems.

Clinical relevance

Optimized surgical management of cleft palate could potentially reduce associated middle ear problems.

Craniofacial shape in children with and without a positive otitis media history

OBJECTIVES

Past studies using traditional morphometric approaches have reported a handful of differences in craniofacial dimensions between individuals with and without otitis media (OM). In this study, a geometric morphometry (GM) approach was used to determine if craniofacial shape is different among children with no history of OM and a history of recurrent acute OM (RAOM) at two different ages.

METHODS

Nineteen standard landmarks were identified on lateral cephalometric radiographs from 79 children (41 Control, 38 RAOM) at 4 years and 52 children (27 Control, 25 RAOM) at 6 years of age. Following Procrustes superimposition of the landmark coordinate data, comparisons of group differences in overall size and shape were performed. Discriminant function analysis and principal component analysis were used to determine which, if any, aspects of shape variation distinguished RAOM from Control groups.

RESULTS

At 4 years of age, craniofacial size and shape were significantly different between RAOM and Control groups (p<0.05). Shape differences were evident in the relative positions of the mandible, cranial base, external acoustic meatus, sphenoid and palate. Those shape differences were not found in the 6-year old group.

CONCLUSIONS

At 4 years of age, the RAOM and Control groups have distinct craniofacial morphologies, but by 6 years of age these differences have largely disappeared. This is consistent with the clinical observation that excess RAOM risk resolves around 6 years of age and the hypothesis that this resolution is partially a result of age-related craniofacial changes.

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.

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.

Denervation of the Tensor Veli Palatini Muscle and Effusion in the Tympanic Cavity

An English springer spaniel was presented for right-sided atrophy of the muscles of mastication, analgesia and paralysis of the face, and vestibular dysfunction. Neurological signs were consistent with a lesion involving the pons and rostral medulla resulting in deficits in the function of the trigeminal, facial, and vestibular nerves. MRI disclosed a right-sided extraparenchymal mass consistent with a trigeminal nerve sheath neoplasm that was compressing and invading the pons and medulla. Atrophy of the muscles of mastication, innervated by the trigeminal nerve, was also observed on MRI. Additionally, effusion was present in the ipsilateral tympanic cavity. Gross and microscopic evaluation of the right tensor veli palatini muscle (TVPM) was consistent with neurogenic atrophy. Effusion in the tympanic cavity was likely the result of an inability to open the auditory tube as a consequence of paralysis of the TVPM. Without the ability to open the auditory tube, gases present within the auditory tube and tympanic cavity may be absorbed, creating a negative pressure environment that leads to fluid transudation and effusion build up. To the authors' knowledge, this is the first report to document neurogenic atrophy of the TVPM with concurrent effusion in the ipsilateral tympanic cavity.

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.

Electrophysiological change in the tensor veli palatini muscle after radiotherapy

CONCLUSION

Electromyography of the tensor veli palatine (TVP) was abnormal and showed mainly myogenic impairment in patients with nasopharyngeal carcinoma (NPC) with secretory otitis media (SOM) after radiotherapy. The diseased ears showed impairment in opening functions of the eustachian tubes (ETs).

OBJECTIVES

To characterize electrophysiology of the TVP muscle using electromyography (EMG) in patients with SOM after radiotherapy of NPC.

METHODS

Twenty healthy volunteers and 20 patients with NPC and SOM after radiotherapy were chosen for assessment of EMG of the TVP during swallowing.

RESULTS

The measurements of average duration and amplitude of action potential, swallowing contraction duration, and peak voltage in NPC patients with both SOM (n = 25) and healthy ears (n = 6) were significantly lower than those of ears (n = 38) in healthy controls (p < 0.01). In patients with NPC, the average action potential duration and swallowing contraction duration in ears with SOM were lower than those of subjects with healthy ears (p < 0.05), whereas no significant difference was found in average amplitude of action potential and peak voltage between them.

Prevalence of effusion in the tympanic cavity in dogs with dysfunction of the trigeminal nerve: 18 cases (2004-2013)

BACKGROUND

Animals with disorders involving the trigeminal nerve or its nuclei in the brainstem can have effusion in the tympanic cavity ipsilateral to the side of the neurological deficits. The tensor veli palatini muscle (TVP), innervated by the mandibular branch of the trigeminal nerve, opens the pharyngeal orifice of the auditory tube. With denervation of the TVP, dysfunction of the auditory tube may occur, which could lead to effusion.

HYPOTHESIS/OBJECTIVES

To determine the prevalence of effusion in the tympanic cavity in dogs with disorders involving the trigeminal nerve.

ANIMALS

Eighteen client-owned dogs were evaluated retrospectively.

METHODS

Retrospective study.

RESULTS

Diagnostic imaging databases were searched for dogs having undergone magnetic resonance imaging (MRI) evaluation for signs referable to dysfunction of the trigeminal nerve. Signalment and neurological examination findings were recorded. The MRI study was evaluated for the presence or absence of effusion. MRI characteristics of the affected trigeminal nerve and the muscles of mastication were recorded. Based on the location of the trigeminal nerve lesion, dogs were divided into three categories: brainstem, trigeminal canal, or extracranial. Eighteen dogs met the inclusion criteria. Six of 18 dogs (33%) had effusion in the tympanic cavity ipsilateral to the affected trigeminal nerve.

CONCLUSION AND CLINICAL IMPORTANCE

A substantial proportion of dogs with a lesion affecting the trigeminal nerve had effusion in the tympanic cavity. This finding likely represents denervation of the TVP muscle, which may have led to dysfunction of the auditory tube.

Eustachian tube function as a predictor of the recurrence of middle ear effusion in children

OBJECTIVES/HYPOTHESIS

In children with ventilation tubes (VTs) inserted for chronic otitis media with effusion (COME), the authors sought to determine whether any parameter of Eustachian tube (ET) function measured by the forced response test (FRT) predicts disease recurrence after the VT becomes nonfunctional.

STUDY DESIGN

Prospective study of those factors that predict disease recurrence in children with VTs inserted for COME.

METHODS

Forty-nine subjects (73 ears; 28 male, 34 white, aged 5.3 ± 1.2 years) with COME had VTs inserted and were evaluable for disease status after the VT(s) became nonfunctional. The FRT was done when the VTs were patent, and results for the last test before the VT became nonfunctional were used in the analysis. After each VT became nonfunctional, the children were followed for disease recurrence over a 12-month period. Logistic regression was used to determine whether the ET opening pressure, closing pressure, and/or dilatory efficiency predicted disease recurrence. That model was expanded to include age, sex, race, history of adenoidectomy, previous VTs, and duration of VT patency as potential predictive factors.

RESULTS

Twenty-nine (40%) ears had recurrence of significant disease within 12 months after the VT became nonfunctional. For the complete logistic regression model, male gender (P = .03), nonwhite race (P = .02), shorter period of VT patency (P = .01), and low dilatory efficiency (P = .01) were significant predictors of disease recurrence.

CONCLUSIONS

A measure of active ET function, dilatory efficiency, but not measures of passive function predicted disease recurrence within the 12 months after the VT became nonfunctional in children with COME.

Synchronous endoscopy and sonotubometry of the eustachian tube: a pilot study

OBJECTIVE

To describe for the first time a method of recording of Eustachian tube (ET) function by simultaneous and synchronous endoscopy and sonotubometry and explore its advantages compared with the performance of these tests independently.

STUDY DESIGN

Observational study.

SETTING

Academic tertiary medical center.

PATIENTS

Eighteen healthy subjects.

INTERVENTION

Endoscopic nasopharyngoscopy with simultaneous, synchronous sonotubometry. Each subject performed three maneuvers: pronouncing the constant "k", swallowing and yawning.

MAIN OUTCOME MEASURES

The number of ET opening as a fraction of all efforts to open the tube, the duration of each opening and the sound intensity recorded by sonotubometry.

RESULTS

Six (35.3%) of 17 subjects used for data analysis did not open their ET during swallowing. Excluding nonopeners, the ET opened in 3 of 4 of the swallows. The average duration of opening of the ET during swallowing was 0.44 seconds. The ET does not open every time the endoscopic view notes dilation. A negative sound pressure wave was recorded in a number of instances, immediately preceding a swallow-related opening. Contraction of the tensor veli palatini muscle was essential for ET opening.

CONCLUSION

Simultaneous synchronous endoscopy and sonotubometry may improve the accuracy of either performed separately as an ET function measurement tool. Sonotubometry may prevent a false-positive endoscopy (ET viewed as open but no functional patency achieved). Endoscopy can lower the threshold considered as positive for sonotubometry. A negative pressure wave recorded by sonotubometry may reflect the ET role of clearing the middle ear of secretions toward the nasopharynx. This novel measurement technique provided additional evidence that the tensor veli palatini muscle provides the final opening action of the ET.

Three-dimensional finite element analysis of Eustachian tube function under normal and pathological conditions

A primary etiological factor underlying chronic middle ear disease is an inability to open the collapsible Eustachian tube (ET). However, the structure-function relationships responsible for ET dysfunction in patient populations at risk for developing otitis media (OM) are not known. In this study, three-dimensional (3D) finite element (FE) modeling techniques were used to investigate how changes in biomechanical and anatomical properties influence opening phenomena in three populations: normal adults, young children and infants with cleft palate. Histological data was used to create anatomically accurate models and FE techniques were used to simulate tissue deformation and ET opening. Lumen dilation was quantified using a computational fluid dynamic (CFD) technique and a sensitivity analysis was performed to ascertain the relative importance of the different anatomical and tissue mechanical properties. Results for adults suggest that ET function is highly sensitive to tensor veli palatini muscle (TVPM) forces and to periluminal mucosal tissue (PMT) elasticity. Young children and cleft palate subjects exhibited reduced sensitivity to TVPM forces while changes in PMT stiffness continued to have a significant impact on ET function. These results suggest that reducing PMT stiffness might be an effective way to restore ET function in these populations. Varying TVPM force vector relationships via changes in hamulus location had no effect on ET opening in young children and cleft palate subjects but did alter force transmission to the ET lumen during conditions of elevated adhesion. These models have therefore provided important new insights into the biomechanical mechanisms responsible for ET dysfunction.

Deleterious sucking habits and atypical swallowing in children with otitis media with effusion

OBJECTIVE

The aim of this study was to investigate the possible correlation between otitis media with effusion, bad sucking habits and atypical swallowing in children affected by otitis media with effusion.

METHODS

65 children, aged from 7 to 12 years, observed in the ENT Department of the "La Sapienza" University of Rome, were enrolled in the study group (group A). All children were affected by otitis media with effusion for more than 3 months. As control group, 60 healthy children, aged from 7 to 12 years were identified (group B). All the children underwent medical history, with evaluation of the sucking habits, ENT examination, tympanometry, orthodontic examination and evaluation of swallowing. In the orthodontic examination the variables analyzed were: maximum mouth opening, right and left mandibular lateral movements and mandibular protrusion. Atypical swallowing was considered to occur when lip activity produced strong tension in the perioral musculature, and/or the tip of the tongue was placed or pushed against the anterior teeth during swallowing.

RESULTS

In the group A, atypical swallowing was found in 33/65 subjects out of the 65 children (50.7%). In the control group (group B) 16/60 children (26.6%) showed atypical swallowing. Compared with group B, deleterious sucking habits were significantly higher (p<0.05) in the study group (28/65 vs. 12/60). In both the study and control group, deleterious sucking habits were present in almost all children with atypical swallowing (28/33 in group A and 12/16 in group B).

CONCLUSIONS

Our data suggest a correlation between otitis media with effusion, deleterious sucking habits and prevalence of atypical swallowing.

Otologic and audiologic outcomes with the Furlow and von Langenbeck with intravelar veloplasty palatoplasties in unilateral cleft lip and palate

OBJECTIVE

Cleft palate increases the risk of chronic middle ear disease and hearing loss. The goal of this report was to determine which of two palate surgeries and which timing of palate surgery were associated with better otologic and audiologic outcomes in children with unilateral cleft lip and palate at 5 to 6 years of age.

DESIGN

Subjects were randomly assigned to the von Langenbeck with intravelar veloplasty or Furlow palate repair, to palate surgery at 9 to 12 months or 15 to 18 months of age, and to the Spina or Millard lip repair.

SETTING

Centralized, tertiary care craniofacial treatment center.

PATIENTS

A total of 673 infants with unilateral cleft lip and palate.

INTERVENTIONS

Palate and lip were repaired using established techniques. Serial otoscopic and audiometric evaluations were performed.

MAIN OUTCOME MEASURES

Hearing and otoscopic findings at 5 to 6 years old.

RESULTS

There were 370 children available for analysis. Hearing and need for tympanostomy tube placement did not differ by palatoplasty, age at palatoplasty, cheiloplasty, or surgeon. Risk of developing cholesteatoma or perforation was higher with Millard cheiloplasty (odds ratio  =  5.1, 95% confidence interval  =  1.44 to 18.11, p  =  .012). Type and age at palatoplasty were not significantly associated with either the rate of developing these sequelae or the rate of achieving bilaterally normal hearing and ear examinations.

CONCLUSIONS

Type of palatoplasty did not influence otologic and audiologic outcomes in 5- to 6-year-olds with unilateral cleft lip and palate. The potential influence of lip repair on otologic outcomes warrants further investigation.

Effects of Velopharyngeal Dysfunction on Middle Ear of Repaired Cleft Palate Patients

Objective

Cleft palates are strongly associated with the development of otitis media due to the anatomic and functional defect of the soft palate musculature and the associated alterations of velopharyngeal muscle insertion on tubal cartilage, or even intrinsic alterations of the cartilage, which affects eustachian tube function. This study will assess velopharyngeal muscle adequacy after palatoplasty through videonasoendoscopy and verify if there is a correlation with otologic status.

Design

Transversal study.

Setting

Otorhinolaryngology and cleft palate outpatient service of the Hospital de Clinicas de Porto Alegre (HCPA), Porto Alegre, Brazil.

Patients

Seventy-three patients with cleft palate or cleft lip and palate between the ages of 6 and 12 years who had already undergone palatoplasty.

Interventions

Videonasoendoscopy for evaluation of velopharyngeal function and videotoscopy to assess middle ear status.

Main Outcome Measures

Severity scale for videonasoendoscopic and videotoscopic findings.

Results

There was no significant correlation between the videonasoendoscopic and the videotoscopic scores in the population studied.

Discussion and Conclusions

Intrinsic defects of the eustachian tube cartilage and of the insertion of the velopharyngeal muscles seem to contribute to the evolution of otitis media in patients with cleft palate, in addition to the actual defect of the soft palate. There was no correlation between the severity of the otoscopic findings and the degree of velopharyngeal dysfunction.

Impact of evolution on the eustachian tube

I posit that humans appear to be the only species that develops otitis media. If animals in the wild had developed middle-ear disease to any significant degree, they would have been selected out during evolution because they would not have survived their predators given the associated hearing loss. Why do humans have otitis media? Evolution has had a significant impact. It is well known that humans are born 12 months too early, which is the result of adaptations to bipedalism and our big brain that, over time, resulted in a relatively small female pelvic outlet compared with nonhuman primates. As a consequence of too early a birth, not only is our immune system immature, but the eustachian tube is too short and floppy in the first year of life. But why is otitis media still common in older individuals? What other adaptation is uniquely human? We developed speech that was associated with descent of the larynx and hyoid bone, which, along with a decrease in prognathism (i.e., facial flattening), resulted in a change in palatal morphology as compared with other primates. Comparative anatomic and physiologic studies have demonstrated significant differences between humans and monkeys, especially in the muscles of the eustachian tube. Paradoxic constriction, as apposed to dilation, on swallowing is a common tubal dysfunction in humans and certain monkey models with chronic middle-ear effusion. My hypothesis is that chronic otitis media with effusion in patients with tubal constriction is a consequence of adaptation for speech and that, most likely, the levator veli palatini muscle is the cause.

The evaluation of the tensor veli palatini muscle function with electromyography in chronic middle ear diseases

Although there are several factors affecting the pathogenesis of chronic otitis, the pathological process has not been entirely defined yet. One of the theories suggested for the development of middle ear diseases is tubal dysfunction. The aim of the study is to analyze the function of the tensor veli palatini (TVP) muscle electromyographically in chronic middle ear pathologies and to evaluate the role of this muscle in eustachian tube dysfunction and pathogenesis of associated middle ear diseases by comparing with the results of healthy individuals.

STUDY DESIGN

A prospective, controlled, clinical trial. We enrolled 24 patients with chronic middle ear pathologies into our study and 18 controls without any previous ear problem. Electromyographic (EMG) needle was inserted into the TVP muscles in all patients transnasally. Functions of the TVP muscle were analyzed by using the amplitudes of the motor unit potential (MUP) and MUP durations detected on EMG. MUP amplitudes and MUP durations were compared statistically in all groups. When the mean MUP amplitudes and durations obtained from TVP muscles of all ears from the patient group were compared to the mean MUP amplitudes and durations obtained from healthy individuals, no statistically significant difference was observed between sick ears and control ears. Values obtained from the sick ears needed to be compared with mean values obtained from the control group separately, since absence of statistically significant difference cannot mean that we should ignore individual muscle dysfunction. The results we obtained from our study support that in the formation of different middle ear pathologies, myogenic defects in the eustachian tube have limited effects, except for existence of a predisposing factor like palate pathology. In all patients with chronic middle ear disease it is not appropriate to expect functional muscle dysfunction, however evaluation of TVP muscle function correctly may be helpful for bringing up the underlying possible muscle and nerve pathologies not in all patients.

Dynamic slow motion video endoscopy in eustachian tube assessment

PURPOSE

The aim of this study was to find out if there is a correlation between dynamic video endoscopic study of eustachian tube (ET) with middle ear disease and to grade ET movements based on dynamic slow motion video endoscopy (DSVE) findings and to determine if DSVE can be used as a useful tool to evaluate tubal function.

MATERIALS AND METHODS

A prospective, case control study was performed on 124 ears in 69 subjects who came to the ears, nose, and throat outpatient department. Transnasal endoscopic examination of the nasopharyngeal opening of the ET during rest, swallowing, and yawning was carried out to study its dilatory movements.

RESULTS

In the control group, among the 61 ears studied, 37 ETs were found normal and 24 tubes, dysfunctional. In ears with middle ear disease (case group), 63 ETs were studied. Ten were found normal, and the remaining, dysfunctional. Ten patulous tubes were observed in this study: 3 in the control group and 7 in the case group. Tubal movements were classified into 4 grades depending on (1) appearance of tubal mucosa, (2) movements of the medial and lateral cartilaginous lamina, (3) lateral excursion and dilatory wave of the lateral pharyngeal wall, and (4) whether tubal lumen opened well or not. Upon correlation of results obtained on DSVE with middle ear disease, the P value was less than .0001, suggesting a significant relationship between the 2. Dynamic ET endoscopy findings of 121 ears (of the total 124 ears studied) were correlated with middle ear manometric studies using Mc Nemar chi(2) test. Seventy-five ears showed complete agreement, and 46 ears showed disagreement. The P value was found to be .000, showing a strong association between the 2 tests. On correlating dynamic ET endoscopy findings in 60 of 63 ears in the case group with middle ear manometry, we noticed that 38 ears showed complete agreement and 22 ears showed disagreement. The P value was found to be .007, which again showed significant agreement between the 2 tests.

CONCLUSION

Dynamic slow motion video endoscopic analysis of ET is a potentially useful tool in the quest for further understanding the pathophysiology of tubal dysfunction. We have attempted to grade ET movements based on severity of tubal pathology. We conclude that DSVE is a vital tool in diagnosing ET dysfunction in patients with middle ear disease. Additional study is required to assess the role of DSVE in predicting outcome after middle ear surgery.

Mechanism and Rate of Middle Ear Fluid Absorption

Several mechanisms have been suggested to explain the clearance of fluids from the middle ear. These include a pumping action through the eustachian tube, mucociliary beating through the tube, outflow of water to the blood due to osmotic gradients and an active Na(+) transport driving water absorption. In order to assess these mechanisms, the middle ear cavity of paralyzed, ventilated (eustachian tube occluded) guinea pigs was filled with fluids varying in osmotic pressure (hypotonic, isotonic, hypertonic) to which a vertical tube was attached. The change in height of fluid in the tube was taken as a measure of changes in middle ear fluid volume. A greater fluid volume reduction was seen with the hypotonic (1/5 saline) solution. A small volume increase was observed with the hypertonic solution. These results provide evidence that in these experimental conditions, water absorption due to osmotic gradients can contribute to middle ear fluid clearance.

Total serum IgE and IgE antibodies specific to house dust mite found in two aged-matched cohorts of children with and without otitis media with effusion

OBJECTIVES

To determine whether otitis media with effusion (OME) is associated with elevated serum immunoglobulin E (IgE) and IgE specific for house dust mite.

DESIGN

Forty-seven children who had evidence of bilateral OME, both otoscopically and on tympanometry, on two separate occasions, 3 months apart were admitted for ventilation tubes. Forty-eight children admitted for minor eye surgery who had otoscopically normal ears and no history of middle ear problems were used as controls. Bloods samples were taken under anaesthesia. Total IgE and IgE radioallergosorbent test (RAST) to house dust mite was measured by the Pharmacia Unicap 100 system. The results from the two groups were compared.

SETTING

Birmingham Children's Hospital.

PARTICIPANTS

Children between the ages of 3 and 10. Children with Down's syndrome, cleft lip and palate, ciliary abnormalities, known immunodeficiencies and cardiac abnormalities were excluded.

MAIN OUTCOME MEASURES

Total IgE and RAST to house dust mite. A RAST of >0.35 was taken to be positive.

RESULTS

There was no statistical difference between the control and study groups for the total IgE. Six children from both study and control groups had a raised house dust mite RAST. There was no difference in the levels between either group.

CONCLUSIONS

Our findings indicate that there is no direct relationship between OME and biochemical evidence of allergy, specifically to house dust mite.

Studies in otitis media: Children's Hospital of Pittsburgh-University of Pittsburgh progress report--2004

OBJECTIVES/HYPOTHESIS

The present Progress Report has summarized the key otitis media clinical trials and laboratory studies conducted since 1969 by investigators at the Children's Hospital of Pittsburgh-University of Pittsburgh (Pittsburgh, PA).

STUDY DESIGN

Review.

METHODS

Included in the discussion are the following: 1) studies of the epidemiology and risk factors; 2) anatomy and pathology of the eustachian tube-middle ear from human temporal bone histopathological specimens; 3) physiology and pathophysiology of the eustachian tube-middle ear in humans and animal models; 4) pathogenesis; 5) otitis media in special populations (e.g., patients with cleft palate, Native Americans, patients with Down syndrome); 6) microbiology; 7) diagnosis; 8) outcomes of randomized clinical trials that evaluated efficacy of nonsurgical and surgical methods of treatment and prevention; 9) studies of certain complications and sequelae (e.g., effect of middle-ear effusion on hearing, early child development, and the vestibular system; chronic suppurative otitis media). Also included are relevant summary tables and 256 references.

Finite element analysis of active Eustachian tube function

The inability to open the collapsible Eustachian tube (ET) has been related to the development of chronic otitis media. Although ET dysfunction may be due to anatomic and/or mechanical abnormalities, the precise mechanisms by which these structural properties alter ET opening phenomena have not been investigated. Previous investigations could only speculate on how these structural properties influence the tissue deformation processes responsible for ET opening. We have, therefore, developed a computational technique that can quantify these structure-function relationships. Cross-sectional histological images were obtained from eight normal adult human subjects, who had no history of middle ear disease. A midcartilaginous image from each subject was used to create two-dimensional finite element models of the soft tissue structures of the ET. ET opening phenomena were simulated by applying muscle forces on soft tissue surfaces in the appropriate direction and were quantified by calculating the resistance to flow (Rv) in the opened lumen. A sensitivity analysis was conducted to determine the relative importance of muscle forces and soft-tissue elastic properties. Muscle contraction resulted in a medial-superior rotation of the medial lamina, stretching deformation in the Ostmann's fatty tissue, and lumen dilation. Variability in baseline Rv values correlated with tissue size, whereas the functional relationship between Rv and a given mechanical parameter was consistent in all subjects. ET opening was found to be highly sensitive to the applied muscle forces and relatively insensitive to cartilage elastic properties. These computational models have, therefore, identified how different tissue elements alter ET opening phenomena, which elements should be targeted for treatment, and the optimal mechanical properties of these tissue constructs.

Experimental model for investigating trans-mucosal gas exchanges in the middle ear of the rat

OBJECTIVE

The total pressure in the middle ear depends on the air composition of this gas pocket, i.e. on gas exchanges occurring through either the Eustachian tube (ET) or mucosa. The aim of this study was to develop an experimental model to investigate the exclusive role of trans-mucosal gas exchanges in the middle ear (ME).

MATERIAL AND METHODS

Both tympanic membranes of 20 Sprague-Dawley rats were punctured under general anesthesia. Rats were divided into two equal groups. Group 1 had no ET obstruction. In Group 2, the ET was blocked, after velar incision, by cauterization and application of cyanoacrylate glue into the lumen. One open transparent glass tube containing a droplet of colored water was placed horizontally and connected hermetically to each ear canal. The ME was then flushed with room air through the tube. Variations in ME gas volume were measured by reading the displacement of the liquid droplet in the horizontal tube. The kinetics of variations in gas volume between groups were displayed and statistically compared using a two-sided t-test.

RESULTS

The pattern of variations in ME gas volume with time was similar in the two groups. Both were characterized by a decrease with three phases and an elimination rate of approximately 0.152 +/- 0.026 microl/min. There was no significant difference in the mean rate of ME volume changes between the two groups.

CONCLUSION

This experimental model allows investigation of trans-mucosal gas exchanges. These exchanges exhibit an absorptive function resulting in a negative pressure that must be compensated, under physiological conditions, by air flow through the ET.

Effect of tensor veli palatini muscle paralysis on eustachian tube mechanics

Several physiological functions, such as regulating middle ear (ME) pressure and clearing ME fluid into the nasopharynx, require an opening of the collapsed eustachian tube (ET). The ability to perform these functions has been related to several mechanical properties of the ET: opening pressure (Popen), compliance (ETC), and hysteresis (eta). These global properties may be influenced by the mechanics of the surrounding tissue and/or the mucosa-air interface. In this study, we investigated the influence of tissue mechanics by paralyzing the right tensor veli palatini (TVP) muscle in 12 cynomolgus monkeys via botulinum toxin injection. A previously developed modified forced-response protocol was used to measure Popen, ETC, and eta under normal conditions and after muscle paralysis. The loss of muscle tone and/or stiffness resulted in a significant decrease in Popen (p < .01) and a significant increase in ETC (p < .01). In addition, muscle paralysis reduced the viscoelastic properties of the TVP muscle and therefore resulted in a significant decrease in eta (p < .05). A comparison with previous measurements on the influence of surface tension mechanics indicates that the ET's compliance is primarily determined by tissue elastic properties. The ET hysteresis, however, is equally affected by viscoelastic tissue properties and surface tension hysteretic properties. Knowledge of how these physical components affect the global mechanical environment may lead to improved treatments for ET dysfunction that target the underlying mechanical abnormality.

Eustachian tube function in older children and adults with persistent otitis media

OBJECTIVE

Otitis media (OM) is most common in infants and young children. Despite a dramatic reduction in its incidence after the age of six, the disease still occurs in older children, adolescents, and may even persist into adulthood. The goal of this study was to identify characteristics of eustachian tube (ET) function in an older population which may underlie their persistent OM.

METHODS

Following a medical history and a head and neck examination, 38 subjects over 6 years of age (64 ears) had their ET function assessed with the forced-response test (FRT). Parameters derived from this test included opening and closing pressures as well as steady-state and active resistances.

RESULTS

Adenoidectomy had previously been performed in 71% of the sample. Clinically, 5% of these subjects had evidence of nasopharyngeal inflammation. The distributions of closing pressure and steady-state resistance were very similar to the distributions of the historic normal controls. The distributions of opening pressure and active resistance were highly skewed relative to the control sample. All study subjects had either abnormal opening pressures or high active resistance, with 79% having both abnormalities.

CONCLUSIONS

If nasopharyngeal inflammation and hypertrophied adenoids are significantly correlated to ET dysfunction and persistent OM, this sample should be free of middle-ear (ME) disease. However, these individuals suffer persistent OM due to ET dysfunction characterized by high opening pressures and high active resistances. The abnormalities underlying these skewed forced-response parameters must be identified and corrected if we are going to alleviate the ME disease in these and similar patients.

Can chronic nasal obstruction cause dysfunction of the paratubal muscles and otitis media? An experimental study in developing Wistar rats

OBJECTIVE

To quantitatively analyze modifications of the paratubal muscles in developing Wistar rats following nasal obstruction.

MATERIAL AND METHODS

Twenty-four Wistar rats were used. Twelve were examined at 6, 8 and 12 weeks after birth and were considered normal controls. The nostrils of the remaining 12 rats were bilaterally obstructed by means of a synthetic resin 28 days after birth. The animals were sacrificed at either 2, 4 or 8 weeks after nostril occlusion. Serial sections were made in the dorsoventral plane and stained with hematoxylin-eosin. Four 5 x 5 microm2 areas, selected within the paratubal muscles, were histologically analyzed and the number of muscular fibers was counted manually.

RESULTS

The number of tensor veli palatini muscle fibers progressively decreased in the obstructed rats compared with age-matched normal controls and in those that had been obstructed for 4 and 8 weeks these reductions were statistically significant.

CONCLUSION

The correct development of the paratubal muscles seems to be linked to physiological nasal breathing and is negatively affected by oral breathing.

Effect of exogenous surfactant on ventilatory and clearance function of the rat's eustachian tube

HYPOTHESIS AND BACKGROUND

The Eustachian tube has three important functions with respect to the middle ear: ventilation, clearance, and protection. Surfactants are assumed to be important to maintain these functions. The administration of exogenous surfactant may therefore be effective to improve the function of the Eustachian tube. This randomized, double-blind, placebo-controlled study was designed to investigate the effect of exogenous surfactant on the function of the Eustachian tube in rats.

MATERIALS AND METHODS

Exogenous surfactant was administered into the middle ear of 10 otologically healthy rats, and 10 other rats received placebo. The effect on the opening and closing pressure (passive ventilatory function) and the dye clearance time (clearance function) of the rat's Eustachian tube was measured.

RESULTS

A significant decrease in the opening pressure was seen after the administration of surfactant. Both surfactant and placebo caused an increase in the closing pressure. A serious disturbance of the dye clearance time was induced in 13 rats, and the test failed in 1 rat. In the remaining 6 rats, no significant differences in the dye clearance time were observed between the two groups.

CONCLUSIONS

Exogenous surfactant decreased the closing forces of the Eustachian tube even in otologically healthy rats. No significant effect on the mucociliary clearance was observed, but this may have resulted from the small number of rats. Additional randomized, double-blind, placebo-controlled trials should be conducted to determine the clinical relevance of these changes and to further assess the effect of surfactant on the function of the Eustachian tube.

The eustachian tube. Update on anatomy, development, and function

Central to many pathologic conditions affecting the middle ear is the failure of the ET to perform its functions of regulation of middle ear pressure, clearance of middle ear secretions, and protection of the middle ear space. Recent advances in radiologic imaging and fiberoptic endoscopes have allowed a more detailed description of the structure and function of this area. Hopefully, with the knowledge gained from advances in this area, more effective medical treatment options for common otologic problems, such as otitis media, will become available.

Why are NICU infants at risk for chronic otitis media with effusion?

Newborns in a Neonatal Intensive Care Unit (NICU) and even later have a high incidence of otitis media with effusion (OME). It is unclear which aspects play a role in the incidence of chronic OME during infancy. In order to investigate the effect of nasally-placed tubes, cranial growth, immune system, and neuromotor function on the occurrence of chronic OME, 83 NICU patients were observed prospectively for middle ear status. Duration and type of treatment with nasal tubes were obtained from the NICU notes. At the NICU, and 1 and 2 years of age the cranial circumference and neuromotor function were assessed. As a proxy for disturbed local immune system parental reports of snoring, mouth breathing and common cold were used. Multivariate analysis revealed that infants treated with nasotracheal and nasopharyngeal tubes showed a marginally significant increased risk for chronic OME (OR=3.2 [95% CI 0.5--21.2]). Treatment with nasogastric tubes appeared to have a lower risk for chronic OME (OR=1.5 [95% CI 0.1--25.1]). No significant effect was found for cranial circumference. Signs of disturbed local immunity during the first 6 months of life (OR=1.4 [95% CI 0.4--4.7]), as well as impaired neuromotor function (OR=1.9 [95% CI 0.5--6.8]), showed also a marginally significant increased risk for chronic OME. The cohort of NICU patients might be relatively too small in order to find significant effects. Although the results of this study should be interpreted cautiously, it is suggested that nasally-placed tubes for ventilatory assistance, disturbed local immunity and impaired neuromotor function are associated with chronic OME.

Effect of laser uvulopalatoplasty on middle ear function

OBJECTIVES

Palatal musculature is known to be responsible for the active opening of the eustachian (auditory) tube. Because laser-assisted uvulopalatoplasty (LAUP) may involve partial division of these muscles, the effect of this procedure on middle ear pressures (MEPs) and middle ear volumes (MEVs) was investigated.

STUDY DESIGN

A controlled interventional trial with one limb receiving treatment and the other none. Preoperative and postoperative measurements were carried out in both groups.

METHODS

A control group of 15 normal volunteers and a study group of 22 patients undergoing LAUP all of whom had normal ears and type A tympanograms before the trial were recruited. Repeat tympanometry was carried out after 3 months in both groups. The results of MEP and MEV were recorded for both groups and analyzed by the Mann-Whitney U test.

RESULTS

A trend toward reduced MEP and MEV was noted in the LAUP group, but did not achieve statistical significance. A study with more patients may achieve significance.

CONCLUSIONS

No significant effects on middle ear pressures or volumes 3 months after LAUP were demonstrated. A much larger study may, however, arrive at a statistically significant result and further work is warranted. Relevant palatal and tubal anatomy is discussed and a brief review of the relevant literature is given.

MRI validation of the accuracy of tympanometric gradient for the diagnosis of OME

Tympanometry provides a rapid, non-invasive and objective assessment of middle ear (ME) status and is widely used for the clinical diagnosis and follow-up of otitis media with effusion (OME). ME pressure, acoustic admittance and tympanometric gradient are the main test parameters used in making assignments to diagnostic classes (i.e. presence or absence of effusion, effusion quantity). Of these, the tympanometric gradient was suggested to be more sensitive to the presence of effusion, but this has not been demonstrated conclusively and no standard definition of that gradient is accepted. In this study, 10 cynomolgus monkeys with experimental OME were used to compare the diagnosis of OME made using three different methods to estimate tympanometric gradient with that provided by simultaneous magnetic resonance imaging (MRI) of the ME. All three methods of tympanometric gradient measurement were highly correlated with the quantity of ME effusion measured by the MRI. Although not significant, the MRI results were better correlated with those for the 'width' method when compared to either the 'difference' or the 'ratio' method of gradient estimation. This study demonstrates the use of MRI as a gold standard for evaluating the accuracy of other methods to diagnose ME effusion.

Repeated inflation does not prevent otitis media with effusion in a monkey model

OBJECTIVE

Investigate the efficacy of repeated middle ear inflation with an inert gas (argon) for preventing the development of middle ear effusion in monkeys with functional eustachian tube obstruction.

STUDY DESIGN

Prospective controlled trial of daily middle ear inflation with five monkeys assigned to the inflation group and four to the control group.

METHODS

The right tensor veli palatini muscle of nine monkeys was paralyzed with botulinum toxin. Tympanometry was done before the procedure and then daily for 21 days. Presence and distribution of effusion were assessed before paralysis and on day 15 using magnetic resonance imaging (MRI). In five right ears inflation was done beginning at the first observation of negative middle ear pressure of < or =200 mm H2O and repeated on all days with pressures < or =-100 mm H2O. Four right ears served as uninflated controls.

RESULTS

Right middle ear pressure decreased in all animals over the course of the study. Pressure returned to near-ambient levels immediately following the argon inflation but was decreased to control levels at the subsequent observation on the following day. MRI at day 15 documented effusion in all right ears with no quantifiable differences in amount or distribution between ears that were and were not inflated with argon.

CONCLUSIONS

Repeated inflation with an inert gas does not prevent middle ear effusion in monkeys with functional eustachian tube obstruction.

Higher rates of pressure decrease in inflamed compared with noninflamed middle ears

Recent clinical trials have renewed interest in middle ear inflation as a treatment for otitis media with effusion. However, air inflation in human beings with significant negative middle ear pressures was shown to be followed by a rapid pressure decrease to approach the preinflation values. In this experiment, the middle ears of anesthetized rhesus monkeys with unilateral inflammation were inflated at different times with air or N2, and pressures were recorded by tympanometry until they had stabilized or the animal had recovered from anesthesia. The results for air inflations reproduced those reported for human beings with negative pressures. Similarly, after N2 inflation a significantly greater rate of pressure decrease and significantly lesser terminal pressures were observed for inflamed ears when compared with the contralateral control ears. However, the rate of pressure decrease and the magnitude of the pressure drop were dampened by sequential N2 inflations. These observations have clinical implications with respect to the efficacy of inflation as a treatment for otitis media with effusion.

Effects of nasal obstruction on Eustachian tube function and middle ear pressure

To evaluate the relationship between nasal obstruction and otitis media, 10 ferrets were studied before and after either unilateral (E = 5) or bilateral (n = 5) nasal obstruction. Observations included otomicroscopic assessments of middle ear status, tympanometric recordings of middle ear pressure and forced-response, inflation-deflation and continuous monitoring tests of Eustachian tube function. During the 6 8 week post-obstruction follow-up period no animal developed evidence of otitis media. Abnormal positive middle ear pressures lasting for the period of follow-up occurred only in the animals with bilateral nasal obstruction. Eustachian tube function test results showed these pressures to be generated during swallowing. No changes in the passive function of the tube were documented in either group, but changes in active function consistent with alterations in the pressure gradient between the middle ear and the nasopharynx were observed in both groups.

A model to explain the rapid pressure decrease after air-inflation of diseased middle ears

OBJECTIVES

Air-inflation in humans and monkeys with significant negative middle ear pressure or with middle ear inflammation was shown to cause greater than ambient middle ear pressure initially, followed by a rapid rate of pressure decrease to approach the preinflation value.

STUDY DESIGN

A mathematical model of middle ear pressure regulation is presented and used to simulate air-inflation of the normal and diseased middle ear.

MATERIALS AND METHODS

The model represents the total volume of the middle ear as consisting of three subcompartments representing the airspace, effusion, and mucosa/blood. Gas exchange among those compartments was assumed to be diffusion limited, and the gas exchange between the mucosa/blood compartment and systemic blood was assumed to be perfusion limited. Disease was modeled as an increase in mucosal blood flow or, alternatively, as an increase in the volumes of the effusion and mucosa/blood compartments.

RESULTS

The predictions of the model agree better with the experimental data when the increased rate of pressure change after middle ear inflation in diseased ears is driven by an increased volume of the effusion compartment as opposed to an increased perfusion rate. The responsible mechanism is a rapid redistribution among subcompartments of the gas volume introduced into the air compartment.

CONCLUSIONS

These results suggest that middle ear inflation with inert gas can be used to diagnose the presence and relative amount of middle ear effusion, and that current protocols for treating otitis media with effusion using inflation need to be modified to optimize their intended effect.

Laterally hypertrophic adenoids as a contributing factor in otitis media

Adenoidectomy has been demonstrated in randomized controlled studies to be effective in the prevention of otitis media with effusion (OME). Despite an apparent lack of correlation between adenoid size and outcome, it has been suggested that the role of adenoid tissue in the pathophysiology of OME relates either to obstruction of the Eustachian tube (ET) with impairment of its function, or to adenoid tissue serving as a reservoir of infection. The aim of this study was to further delineate the relationship between adenoid hypertrophy and OME. This prospective survey was performed in an ambulatory care setting of a tertiary care pediatric hospital, where data was collected on 273 consecutive adenoidectomy patients. At the time of surgery, adenoid position in relation to the ET orifice was recorded as well as concurrent procedures performed (e.g. pressure equalization tubes; PET). Sixty percent of patients undergoing simultaneous PET insertion were found to have laterally hypertrophic adenoid tissue encroaching upon the ET orifice versus only 22% for those undergoing adenoidectomy alone. Thus, a strong correlation was found to exist between OME, requiring the placement of PET and lateral adenoids abutting the torus tubarius (chi2 = 39.12; P < 0.001). The clinical relevance of this finding is that it may allow the prediction of children with OME, who will benefit most from undergoing adenoidectomy. Patients with OME requiring PET insertion, who are found to have lateral adenoid hypertrophy encroaching upon the ET orifice, could be selected for adenoidectomy, thus allowing a more judicious application of this surgical procedure in the setting of OME.

New Aspects of Secretory Otitis Media, Eustachian Tube Function and Middle Ear Gas

The insertion of ventilation tubes to equalize pressure in the middle ear is the most common procedure used to treat otitis media. This article evaluates the advantages and drawbacks of ventilation and explores the various roles of the components of middle ear pressure, with special emphasis on oxygen-derived free radicals.