Autophony in patients with patulous eustachian tube: experimental investigation using an artificial middle ear.

OBJECTIVE: To investigate the contribution of anatomical factors, such as the caliber of the patent eustachian tube (ET) and the volume of the middle ear cavity, on vocalized sound transmission to the inner ear. METHODS: Model experiment using artificial middle ear. RESULTS: In the present model experiment, sound transmission from the pharynx to the inner ear under patulous conditions was affected by the caliber of the ET and by the mastoid volume, especially in the low-frequency region, that is, a larger caliber of the ET and smaller mastoid volume resulted in greater sound transmission from the pharyngeal space to the inner ear. CONCLUSION: Patulous symptoms may be more distressful in patients with poorly developed mastoid cavity than in those with well-aerated mastoid under similar conditions of patulous ET.     

Surfactant in the middle ear and eustachian tube: a review

There has been a recent surge in research on surfactant and surfactant proteins. Fields ranging from immunology to surface chemistry are making contributions to our understanding of this multifunctional compound. This paper reviews the literature on the structure and function of Eustachian tube surfactant. It covers the proposed functions of endogenous surfactant in normal physiology, as well as the experimental applications of exogenous surfactant in the treatment of otitis media. The analysis is based on four platforms of research: the role of surfactant in the innate immune system, the effect of surfactant on surface tension and Eustachian tube opening pressure, the capacity of surfactant to alter the rheological properties of mucus and the efficiency of the mucociliary system, and the ability of surfactant to mitigate oxygen free radical damage.     

Seasonal allergic rhinitis and its effects on eustachian tube function and middle ear pressure.

Middle ear pressure was recorded from 396 ears and aural symptoms inquired of 198 adult subjects with seasonal allergic rhinitis. Evidence of eustachian tube dysfunction was found in 24% of subjects. Increased duration of exposure to pollen over a further 2 weeks increased the incidence of eustachian tube dysfunction to 48%. The development of eustachian tube dysfunction did not correlate with the severity of nasal symptoms.     

Mucoepidermoid carcinoma arising from the eustachian tube and middle ear

We report a case of mucoepidermoid carcinoma (MEC) originating from the eustachian tube and middle ear. A 31-year-old male who presented with otorrhoea and methicillin-resistant Staphylococcus aureus (MRSA) in the right ear was admitted to hospital due to cerebral infarction and deep vein thrombosis. After recovery, biopsies from a granulomatous mass found in the middle ear during operation for chronic otitis media revealed intermediate-grade MEC and a nasopharyngeal mass identified after surgery also revealed the same result. He received combined radiation therapy and chemotherapy and no residual or recurrent tumour was detected after two years of follow-up.     

Mucosa-associated lymphoid tissue in middle ear and eustachian tube

The presence of mucosa-associated lymphoid tissue (MALT) was investigated histopathologically in every 20th section from 99 vertically cut, celloidin-embedded temporal bone-eustachian tube (ET) specimens. Among specimens from infants and children between 1 month and 7 years of age, MALT was found in 22 of 44 (50%). However, in 26 adults over 18 years of age, MALT was found in only 2 specimens (7.7%), a significantly lower incidence than that in infants and children. Moreover, MALT did not appear in any of the 21 neonates under the age of 1 month. All 99 specimens were classified into 2 groups: 41 specimens with otitis media (OM) and 58 specimens without OM. The presence of MALT was significantly higher in specimens with OM (43.9%) than in specimens without OM (13.8%). Mucosa-associated lymphoid tissue was found in the ET, middle ear, and mastoid process in 18 specimens (43.9%). 5 specimens (12.2%), and 1 specimen (2.4%) with OM, respectively, and in 8 (13.8%), 0, and 0 specimens without OM. In regard to the distribution of MALT, it occurred more frequently in the pharyngeal half of the cartilaginous portion of the ET than in the rest of the ET, middle ear, and mastoid; the presence was significantly greater in the inferior half of the cartilaginous portion of the ET than in the superior half. Inflammatory cell infiltration in the cartilaginous and bony portions of the ET was significantly greater in specimens with OM than in specimens without OM with no MALT. However, even in some specimens without OM, inflammatory cells were found in the ET, particularly in the pharyngeal half of the cartilaginous portion of the ET. These findings suggest that MALT has a close relationship to OM and that it may be a local response to repeated infection.     

Direct measurement of middle ear pressure through the eustachian tube

Summary We report a method for measuring middle ear pressure through the eustachian tube. We used a 1-mm-diameter micro-tip catheter pressure transducer (Mikro-tip) and inserted this into the tympanic cavity through the eustachian tube. In preliminary studies, we measured four normal ears, two ears with tubal dysfunction, one ear with a dry perforation and 13 ears with otitis media with effusion (OME). Among those ears with OME, three showed negative middle ear pressure, three slight positive pressure and one normal pressure. These findings suggest that our transtubal method is reliable and useful for measuring middle ear pressure.     

Clearance of the eustachian tube under negative middle ear pressure

The influence of negative middle ear pressure on clearance function of the eustachian tube was examined in cats. In experiment 1, mucociliary clearance of a colored fluid through the eustachian tube was examined under negative middle ear pressure. The results showed that negative pressure affects mucociliary clearance only at quite high levels. In experiment 2, muscular clearance of fluid under negative middle ear pressure was investigated during electrical stimulation of the tensor veli palatini muscle. It was found that massive discharge of fluid by the muscle activity occurs only when the negative middle ear pressure was low. For massive discharge of effusion, muscular clearance is more effective than ciliary clearance. The findings suggest that it is clinically important to maintain middle ear ventilation.     

Direct measurement of middle ear pressure through the eustachian tube

We report a method for measuring middle ear pressure through the eustachian tube. We used a 1-mm-diameter micro-tip catheter pressure transducer (Mikro-tip) and inserted this into the tympanic cavity through the eustachian tube. In preliminary studies, we measured four normal ears, two ears with tubal dysfunction, one ear with a dry perforation and 13 ears with otitis media with effusion (OME). Among those ears with OME, three showed negative middle ear pressure, three slight positive pressure and one normal pressure. These findings suggest that our transtubal method is reliable and useful for measuring middle ear pressure.     

Surface tension of secretions from eustachian tube and middle ear

The surface tension of secretions from the pharyngeal orifice of the eustachian tube in eight rabbits was analyzed with a modified maximum-bubble pressure method. Measurements were made before, during, and after intravenous injections of isoprenaline (10 micrograms/kg). Surface tension was found to be 57.6 +/- 0.9 (mean +/- SEM) mN/m before injections, and was not significantly changed by isoprenaline. The surface tension in middle-ear secretions from children with secretory otitis media was also determined, the serous type of secretion measuring 62.0 +/- 1.4 mN/m (n = 8), and the mucoid type 70.7 +/- 2.6 mN/m (n = 9). In another ten humans, measurements of tears were performed, and the surface tension was found to be 59.9 +/- 2.2 mN/m. This bubble technique promises to be useful for the evaluation of surface tension when the available sample volume is very small.     

Nasal surgery and eustachian tube function: effects on middle ear ventilation

Objectives: To investigate the effect of nasal obstruction surgery on eustachian tube function and middle ear ventilation. Design: Prospective study. Setting: University Campus Bio‐Medico of Rome. Participants: Forty consecutive patients who underwent nasal surgery were evaluated for middle ear ventilation and tubal function. Main outcome measures: Pre‐ and postoperative Valsalva and Toynbee tubal function tests, tympanometry and ear fullness sensation were evaluated for both ears of each patient. Results: Results of postoperative tubal function tests were significantly better than preoperative ones (90% versus 46%; P < 0.001). No significant difference in tympanometric values was found. The majority (95%) of the patients reported a postoperative improvement of ear fullness sensation compared with preoperative (25%; P < 0.001). Conclusions: Surgery for chronic nasal obstruction significantly improves clinical tubal function but 1‐month postoperative tympanometric findings remain almost the same.     

Reflux of nasopharyngeal content into middle ear through the eustachian tube

Whether nasopharyngeal content passes into the middle ear in patients without any head and neck pathology during the recovery phase of anesthesia is shown with an objective and prospective method. Thirty-eight patients, 21 female and 17 male, aged between 17 and 76, were included in the study. During the recovery phase of general anesthesia, 10 ml of 5 mCi Tc-99m-MAA was administered intranasally to the patients with a 10-F catheter. A manometer-adapted cuffed intubation tube was placed in the nasal passage so that the cuff was located at the choana. The pressure changes reflecting to the nasopharynx were recorded. The patients were extubated 10 min after the radionuclide was applied. The scintigraphic evaluation was done at the end of the 1st hour of the application of radionuclide. Transmission and emission views were taken with a gamma camera. Passage of nasopharyngeal content into the middle ear via the eustachian tube was not a statistically significant observation. The mean value of maximum pressure reflecting from the nasopharynx did not differ significantly between patients. Our study does not support the hypothesis that nasopharyngeal content passes directly through the eustachian tube into the middle ear and causes deleterious effects.     

儿童鼻窦炎对咽鼓管与中耳传音功能的影响

目的：探讨儿童鼻窦炎对咽鼓管与中耳传音功能的影响及程度,观察治疗鼻窦炎后,中耳传音功能障碍的恢复情况。方法：对儿童鼻窦炎100例和正常儿童50例行耳科检查、咽鼓管咽口观察、声阻抗检查、纯音测听,对比结果;对鼻窦炎合并耳病变的68例患者（128耳）行有针对性的治疗。结果：鼻窦炎患者中鼓膜异常率为64%、咽鼓管咽口异常率为62%、咽鼓管功能异常率为63.5%、鼓室导抗图异常率为62.5%,听力减退47.5%,与正常儿童组相比,差异有统计学意义（P＜0.01）。急性鼻窦炎、亚急性鼻窦炎与慢性鼻窦炎中耳病变的发生率和程度相比,差异有统计学意义（P＜0.05）。治疗鼻窦炎后,中耳传音功能障碍有明显改善。结论：儿童鼻窦炎引起咽鼓管功能的改变,中耳病变发生率较正常儿童显著增高;随病程的延长,发病率增高且程度加重。     

Evolution of middle ear changes after permanent eustachian tube blockage

OBJECTIVE: To develop a valid animal model for otitis media with effusion (OME). DESIGN: Forty specific pathogen-free Wistar rats underwent a procedure based on the permanent obstruction of pharyngeal eustachian tube by means of electrocoagulation without any manipulation. SETTING: Ear Research Group, Department of Otorhinolaryngology, Puerta de Hierro Hospital, Universidad Autonoma de Madrid, Madrid, Spain. MAIN OUTCOME MEASURES: The assessment of OME by otoscopy and tympanometry. The rats were humanely killed at 15 and 90 days, and temporal bones were obtained and processed for histopathologic study. RESULTS: The histopathologic study of the temporal bones demonstrated the occurrence of chronic effusion and mucosal changes owing to mucoperiosteal enlargement. CONCLUSIONS: Comparison with other experimental models was made. Our animal model was consistent and reproducible and resembled human OME.     

Developmental anatomy of the eustachian tube and middle ear in mice.

PURPOSE: It is generally accepted that the development of the tubotympanum has significant bearing on the susceptibility to ear infection. A detailed study of the differentiation of ciliated cells in secretory elements will be useful in understanding both the normal physiology and the pathology of the tubotympanum. METHOD: Serially sectioned temporal bones of 76 mice ranging from gestational age day 11 to postnatal day 21 were examined microscopically. RESULTS: During the period of gestation, the tubotympanic recess was formed at the 12th day and began to extend to form the middle ear between the 13th and 14th days. A rapid increase in the volume of the tubotympanic recess was observed between the 15th and 16th days when a definitive division of the tubotympanic recess into the eustachian tube and middle ear cavity was observed. Postnatally the tubotympanum attained an adult form around day 9, and the maximum change of middle ear volume was noted on day 11, when the mesenchymal tissue in the middle ear cavity disappeared completely. Development of the ciliated cells was observed concurrently in both the eustachian tube and middle ear on the 16th gestational day, one day earlier than the appearance of the epithelial secretory cells in both the eustachian tube and middle ear. The number of ciliated cells and secretory cells increased rapidly after birth. Tubal glands were well developed with evidence of secretory activity around the time of birth. CONCLUSIONS: Based on these findings, one can conclude that the mucociliary defense system starts to develop during the fetal stage and is well established immediately after birth.     

Clearance function of eustachian tube and negative middle ear pressure.

Two experimental studies were performed using 18 cats in order to elucidate the mechanism of the long-lasting course of otitis media with effusion. First, the middle ear (ME) pressure was monitored for 2.5 to 7 hours after filling the whole ME space with saline. On average, -150 mm H2O of negative ME pressure was induced in 3.1 hours. Second, the residual volume of saline with antibiotics, which was put into the ME space 2 to 7 days before, was compared between the side on which tubal ventilatory function was abolished (resection of tensor veli palatini muscle and hamulus pterygoideus) and the opposite, control side. The percentage of the residual volume to the original volume put into the ME was significantly higher on the experimental side (Wilcoxon's ranking test, t = 27.0, p less than .05), and in one ear on the experimental side, the ME pressure showed-150 mm H2O just before the bulla was opened 2 to 7 days later. These results seem to indicate that tubal ciliary clearance function can induce negative ME pressure when there is fluid in the ME, and that the negative ME pressure induced by clearance of the ME fluid may disturb further clearance of the ME fluid. This condition may cause the long-lasting course of otitis media with effusion.