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.     

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.     

Site of eustachian tube dysfunction in patients with otitis media with effusion

This study was conducted to identify an exact site of ventilatory dysfunction within the eustachian tube among patients with otitis media with effusion (OME). Using 10 adults with OME, a fine polyethylene tube with a small pore at its tip was inserted into the eustachian tube via its pharyngeal orifice. Negative middle ear pressure was applied through a ventilation tube in the eardrum, and the patients were asked to swallow repeatedly at every 5-mm depth of insertion of the polyethylene tube toward the middle ear. Negative middle ear pressure could be equilibrated by swallowing within 10 mm of tube advancement from the pharyngeal orifice of the eustachian tube in seven of ten patients. It was concluded that the site of tubal ventilatory dysfunction is in the distal part of the cartilaginous portion of the eustachian tube in most adult patients with OME.     

The role of allergy in the pathogenesis of otitis media with effusion

To explain an allergic basis for the development of otitis media with effusion (OME), it was suggested that the middle ear mucosa can act as an allergic "shock organ." To evaluate this possibility, 16 juvenile rhesus monkeys were passively sensitized to pollen by intravenous injection of allergic human serum. All ears were then challenged by insufflation of pollen via the nose and eustachian tube (ET), twice daily, for four to five days. Daily tympanometry and otomicroscopy were performed, and on the last day of challenge, tympanocentesis was done to recover effusions. Five animals were killed and the middle ears were processed for histologic study. The results showed that none of the ears developed a middle ear effusion or OME. It is concluded that middle ear challenge with an appropriate pollen antigen in passively sensitized rhesus monkeys does not initiate an inflammatory reaction in the middle ear or induce OME.     

Tympanic membrane atrophy, scarring, atelectasis and attic retraction in persistent, untreated otitis media with effusion and following ventilation tube insertion

Two hundred and twenty two children with persistent bilateral otitis media with effusion (OME) were treated with unilateral ventilation tube insertion and no treatment to the contralateral ear. The tympanic membrane changes in the operated and unoperated ears were compared during a 12 year follow-up. Segmental atrophy resulted from tube insertion whereas minor scarring and thickening of the pars tensa was related to the middle ear condition. Eighty three percent of untreated ears and 85% of those treated with tubes did not develop atelectasis. Sixty percent of untreated ears and 64% of treated ears did not develop attic retraction. Very few cases (1.5 and 2%) in untreated and treated ears, respectively developed severe atelectasis. The overall duration of OME was assessed from the pre-operative history of hearing loss, the 3 month period of pre-operative observation and the post-operative time with effusion. There is a relationship between duration of the disease and development of both atelectasis and attic retraction.     

Structural changes in the rat middle ear mucosa due to endotoxin and eustachian tube obstruction

The middle ears of 48 rats were used to examine the effects of endotoxin injection, eustachian tube obstruction or a combination of eustachian tube obstruction and endotoxin injection. Animals were killed after 1, 2, 4, or 12 weeks and the middle ears processed for light and scanning electron microscopy. Compared to the normal middle ear mucosa, the epithelial layer was more pseudostratified, cuboidal or cylindrical after endotoxin injection or obstruction of the eustachian tube. In the early phase, numerous ciliated cells occurred in areas originally almost devoid of these cells. At 3 months, degeneration of ciliated cells was observed. The combination of eustachian tube obstruction and endotoxin injection also induced a more pseudostratified, cuboidal or cylindrical epithelium with an increased number of goblet cells. However, an early decrease occurred in the number of ciliated cells in the tympanic orifice of the eustachian tube. Furthermore, inflammatory cells, mainly PMNs, macrophages and lymphocytes, invaded the subepithelial layer after eustachian tube obstruction and endotoxin injection. These structural changes resulted in an impairment of the mucociliary transport system for clearance of the middle ear cavity. For this reason we believe that both endotoxin and eustachian tube obstruction or dysfunction play an important role in inducing persistent mucosal changes in the middle ear cavity, thereby prolonging otitis media with effusion. Received: 13 February 1998 / Accepted: 4 August 1998     

The role of allergic rhinitis in the development of otitis media with effusion: effect on eustachian tube function

PURPOSE: The pathogenesis of otitis media with effusion (OME) is considered multifactorial, with viral upper respiratory tract infection and eustachian tube dysfunction. Allergy may be related to the pathogenesis of OME or to another etiological factor. We investigated the role of allergic rhinitis (AR) in children with OME and evaluated eustachian tube function in patients with AR. MATERIALS AND METHODS: We prospectively analyzed the prevalence of AR, serum eosinophil count, and serum total IgE concentrations in 123 children with OME and in 141 controls. IgE concentration in middle ear effusion was compared in children with OME with and without AR, and eustachian tube function after a nasal provocation test was compared between patients with AR and controls. RESULTS: The prevalence of AR in children with OME (28.4%) and control subjects (24.1%) did not differ significantly. These 2 groups also showed no differences in total eosinophil count and serum and middle ear effusion IgE concentration. Abnormalities in eustachian tube function were the same in patients with AR and controls. CONCLUSIONS: Allergic rhinitis may not be related to the development of OME in children.     

Eustachian tube function before recurrence of otitis media with effusion

OBJECTIVE: To study the role of eustachian tube function in the development of recurrent otitis media with effusion (OME) in children treated with tympanostomy tubes for OME. DESIGN: Prospective cohort study. SETTING: Three academic and general hospitals. PATIENTS: Children aged 2 to 7 years with a first clinical episode of OME that persisted for at least 3 months; 136 (81%) of 168 eligible children participated. All children received tympanostomy tubes for bilateral OME at study entry. MAIN OUTCOME MEASURE: Recurrence of OME within 6 months of tube extrusion. RESULTS: No statistically significant differences were present in eustachian tube function test results between ears that developed recurrent OME and those that did not. The difference in passive ventilatory function between ears with and without OME recurrence was 10 daPa (95% confidence interval, -24 to 43 daPa) for opening pressure and -3 daPa (95% confidence interval, -18 to 11 daPa) for closing pressure. The overall difference in the proportion of ears with and without OME recurrence that could not equilibrate positive and negative applied pressures was 12% (95% confidence interval, -2% to 26%). The proportions of ears with and without OME recurrence that induced negative pressure in the middle ear by forcefully sniffing were 22% and 31%, respectively (P = .75). CONCLUSION: Measurement of ventilatory and protective eustachian tube function using the forced response test, the pressure equilibration test, and the sniff test has no value in predicting whether children have an increased risk of OME recurrence.     

Anatomy of the chinchilla bulla and eustachian tube: I. Gross and microscopic study

The middle ear mucosa and eustachian tube of the normal chinchilla were studied quantitatively and under light microscopy to determine the distribution of each cell type of the lining epithelium and subepithelial gland. The middle ear mucosa consisted of columnar epithelium, cuboidal epithelium, and squamous epithelium. The lining epithelium of the eustachian tube was ciliated pseudostratified columnar epithelium. These epithelia were composed of ciliated, secretory, nonciliated (nonsecretory), and basal cells. The density of the ciliated cells was highest in the columnar epithelium area of the transitional zone of the middle ear mucosa. However, the density of the secretory cells was highest in the pharyngeal orifice of the eustachian tube. The nonciliated cell density was highest in the squamous epithelium area of the middle ear mucosa and decreased progressively toward the tympanic orifice of the eustachian tube. In the eustachian tube, the nonciliated cell density was highest in the pharyngeal portion of the eustachian tube, especially in the upper portion of the lateral wall. The subepithelial glands were tubuloacinar mixed glands composed of serous demilunes and mucous acini. The glands were localized primarily in the pharyngeal orifice and pharyngeal portion of the eustachian tube, and their ductal openings were present primarily in the inferior portion of the eustachian tube.     

Negative middle ear pressure and otitis media with effusion after surgery under general anesthesia

Abstract Conclusion: Negative middle ear pressure was observed in many patients and otitis media with effusion (OME) developed in 3.3% of ears after surgery under general anesthesia. Gas dynamics in the middle ear cavity induced by nitrous oxide inhalation anesthesia and transient blockage of the eustachian tube induced by surgery are considered to be involved in development of OME after surgery under general anesthesia. Objectives: The goal of this prospective study was to investigate middle ear pressure and the prevalence of middle ear effusion in patients after surgery under general anesthesia, to ascertain whether surgery under general anesthesia induces OME. Methods: Otoscopic inspection and tympanometry were performed before surgery (Pre), 1-2 days after surgery (Post-1), and 5-9 days after surgery (Post-2) under general anesthesia in 180 ears of 97 adult patients. Results: Effusion accumulated in the tympanum in six ears (3.3%) of five patients at Post-1. All patients were anesthetized with nitrous oxide. At Post-2, effusion disappeared in all cases. The mean middle ear pressure in all ears was -17.8 daPa at Pre and -60.6 daPa at Post-1, showing a significant reduction from Pre to Post-1 (p < 0.001). At Post-2, the pressure was -18.4 daPa, with no significant difference from that at Pre (p = 0.74).     

鼻内镜下咽鼓管扩张导管治疗慢性分泌性中耳炎13例分析

目的 探讨鼻内镜下咽鼓管扩张导管治疗慢性分泌性中耳炎的方法和疗效。方法 对13例(15耳)慢性分泌性中耳炎患者采用经鼻内镜下插入咽鼓管扩张导管至其峡部,加压并持续扩张其球囊2min,然后经外耳道行鼓膜穿刺抽液,用地塞米松冲洗鼓室,再用含丝裂霉素C明胶海绵涂擦鼓膜穿刺部5min。结果 全部病例均一次插管成功,随访4~5个月,11例(11耳)疗效满意,耳闷胀感消失,声阻抗提示鼓室图由“B”型恢复为“A”型,纯音听阈测试提示听力提高10~20dB,内镜检查鼓室无积液,无感染、出血、鼓膜穿孔等并发症。2例伴有过敏性鼻炎患者(4耳)于术后3个月又出现闷胀感,轻度听力下降,但无鼓室积液,经抗炎和抗过敏治疗后症状消失。结论 鼻内镜下咽鼓管扩张导管治疗分泌性中耳炎操作简便、微创,疗效好。     

Middle ear ventilation tubes

Twenty years have now passed since the first tube was placed through the tympanic membrane for middle ear ventilation. In this relatively short period of time, many different ideas for tube design have emerged and are presented. The types of middle ear fluid formation and the relationship of this formation to impaired eustachian tube function are discussed. The main indication for indwelling tubes is chronic secretory otitis media with effusion which fails to respond to conservative treatment; however, indications have been expanded with continued experience. The complications associated with the use of middle ear ventilation tubes are presented. Five years' experience using ventilation tubes in 1,460 ears is reported. Conclusions are based on data compiled from this study.     

Cytokine expression in experimental chronic otitis media with effusion in mice

OBJECTIVES: Although otitis media with effusion (OME) is still a common disease in children and adults, the pathogenesis is not yet fully understood. We studied the effects of intratympanic injection with endotoxin purified from nontypeable Haemophilus influenzae on the characteristics of middle ear effusion (MEE). METHODS: Murine model of OME was developed by eustachian tube (ET) blockage followed by intratympanic inoculation with endotoxin (endotoxin group) or saline (control group). The mice were decapitated and histological changes and the production of inflammatory cytokines in MEEs were examined 3 days, 2 weeks, and 2 months after injection. RESULTS: All mice showed OME until 2 months after ET blockage. Most MEEs in the control group were serous, and mucoid or pultaceous MEEs were found only in the endotoxin group. Subepithelial space of middle ear mucosa was severely thickened with the infiltration of a large number of mononuclear cells in the endotoxin group. The levels of tumor necrosis factor-alpha (TNF-alpha) in MEEs were significantly higher in the endotoxin group than in the control group at all time points. Further, in situ hybridization showed that TNF-alpha messenger RNA was expressed not only by leukocytes and macrophages in MEEs but mononuclear cells present in the subepithelial space of middle ear mucosa. CONCLUSIONS: These results indicate that ET blockage is essential for the induction of serous MEE and additional administration of endotoxin is associated with the production of mucoid MEE accompanied by histological changes with inflammatory cell infiltration and cytokine production in the tympanic cavity.     

Eustachian tube endoscopy in patients with chronic ear disease

OBJECTIVES/HYPOTHESIS: A paucity of research exists on trans-eustachian tube endoscopy to evaluate the status of the eustachian tube. Fuller examination of the role of the eustachian tube in chronic ear disease is needed, particularly because the eustachian tube has been implicated in the chronicity and pathogenesis of chronic ear disease. Therefore the purpose of this study was to evaluate the eustachian tube, based on observations from trans-eustachian tube endoscopy. STUDY DESIGN: Twenty-two adult patients with chronic ear disease gave informed consent to participate in a prospective, trans-eustachian tube endoscopic investigation. METHODS: Flexible, fiberoptic, nonarticulating (outside diameter of 0.5 mm) and articulating (outside diameter of 1.0 mm) endoscopes (coherent fused bundle of 3,000 pixels) were employed. The eustachian tube endoscopy was performed under general endotracheal anesthesia as the initial part of a larger, otological surgical procedure for chronic ear disease. The endoscope was passed from the middle ear (transtympanic approach) to the nasopharynx. RESULTS: The 0.5-mm endoscope passed entirely through the eustachian tube from the tympanic orifice into the pharyngeal orifice in 16% of the cases. Stenotic blockage occurred at the infundibulum in 37%, isthmus in 42%, and fossa of Rosenmuller in 5% of cases. The eustachian tube mucosa was abnormal in 64% of cases. The risk for abnormal eustachian tube mucosa was four times greater for persons with long-standing disease (> or = 20 y) than for persons without long-standing disease (<20 y). The mean therapeutic efficiency of ossicular reconstruction was higher for the subgroup with normal than for the subgroup with abnormal eustachian tube mucosa. CONCLUSIONS: The findings of trans-eustachian tube endoscopy provide objective evidence concerning eustachian tube status in persons with chronic ear disease and have implications for the timing of surgical intervention (ossicular reconstruction).     

Partial oxygen tension of middle ear cavity in a normobaric environment

The present theory of eustachian tube function and middle ear ventilation posits that oxygen absorbed by the middle ear mucosa causes negative middle ear pressure which is relieved by periodic opening of the eustachian tube during swallowing and yawning. Measured by a PO2 sensor (Clark type) inserted into the middle ear cavity of normal adults through the eustachian tube, the partial oxygen pressure of the tympanic cavity was found 53.7 +/- 6.5 Torr (N:22). It was about one-third of ambient pressure (about 150 Torr), and showed no change when the eustachian tube was opened by swallowing. Our second study measured the effect of alterations in the systemic arterial blood oxygenation on middle ear gas exchange in 23 guinea pigs ventilated using 21% (room air), 50%, 70% and 100% oxygen at constant carbon dioxide blood gas tension. Partial oxygen tension (PO2) of middle ear cavity was measured by inserting a PO2 sensor into the tympanic bulla through a bore hole. The following results were obtained: (1) PO2 of the middle ear cavity was 39.3 +/- 2.2 Torr at room air, 42.2 +/- 0.84 Torr at 50%, 46.6 +/- 1.1 Torr at 70% and 54.5 +/- 3.7 Torr at 100% oxygen breathing. (2) There was a significant correlation between PO2 of the middle ear cavity and systemic arterial hyperoxygenation noted. Y = 30.79 + 0.056.X (r = 0.9440) (3) The rate of oxygen diffusion in the middle ear cavity was 2.665 x 10(-5) ml/min/cm2 and the rate of oxygen absorption in the middle ear space was 2.874 x 10(-5) ml/min/cm2. No significant difference between the rate of diffusion and that of absorption of oxygen in the middle ear cavity was noted. In our third study, electron microscopy shows that the submucosal capillaries of the human mastoid cells are structures which facilitate the intra- and extravascular transport of substances. It is known from these results that tympanic cavity pressure is kept equal to ambient pressure, or slightly higher to atmospheric pressure, by the respiratory function of the middle ear and mastoid cells so that outflow of air from the tympanic cavity to the pharyngeal orifice occurs during the ventilation of the eustachian tube at ambient pressure and inflow of air from the pharynx to the tympanic cavity is prevented in the absence of environmental pressure changes. The middle ear cavity has respiratory function, and in particular, such function of the mastoid cavity, which is larger in volume than the tympanic cavity, plays a significant role.(ABSTRACT TRUNCATED AT 400 WORDS)     

中性粒细胞胞外诱捕网络在分泌性中耳炎中的作用及其研究进展

分泌性中耳炎(OME)是以传导性聋及鼓室积液为主要特征的中耳非化脓性疾病。冬春季多发,是儿童和成人听力下降的常见原因。部分患者的病程过长,最终导致黏连性中耳炎、胆脂瘤等病变,形成不可逆的听力损害。OME的发生发展主要与咽鼓管功能障碍、中耳局部感染和变态反应相关,但是,其病理机制目前尚不明确。中性粒细胞胞外诱捕网络(NETs)作为中性粒细胞捕获和杀灭病原体的一种新作用机制,参与循环、呼吸、肿瘤及自身免疫性疾病的发生和发展;并且作为新的治疗靶点,NETs的抑制剂对这些疾病的治疗已经取得了一定进展。前期研究在OME患者或动物模型的中耳积液中发现了NETs相关蛋白,提示NETs也参与OME的疾病进展。本文就NETs在OME中的作用及其研究进展作一综述。     

Influence of the Gas Exchange Function Through the Middle Ear Mucosa on the Development of Sniff-Induced Middle Ear Diseases

To investigate the influence of gas exchange function through the middle ear mucosa on the development of sniff-induced middle ear diseases, the authors examined the mastoid pneumatization among patients with sniffing habit using computed tomography, and also examined the change of negative middle ear pressure induced by sniffing using tympanogram. In 20 ears with cholesteatoma or adhesive otitis media, the areas of mastoid cavity measured at the level of the lateral semicircular canal were significantly smaller than those in 26 ears with otitis media with effusion (OME) or attic retraction and in eight normal ears with sniffing habit (P < .01 and P < .0001, respectively). In 26 ears with OME or attic retraction, the areas of mastoid cavity were significantly smaller than those in eight normal ears with sniffing habit (P < .0001). By contrast, in the four ears with sniff-induced middle ear disease, the recovery of negative middle ear pressure in 5 minutes without swallowing was less than 10 mm H₂O, whereas in all seven ears with normal eardrum, negative middle ear pressure recovered by more than 20 mm H₂O in 5 minutes. These findings suggested that impairment of gas exchange function through the middle ear mucosa, as well as eustachian tube dysfunction, might be closely related to the development of sniff-induced middle ear diseases.     

Optimizing effectiveness of laser tympanic membrane fenestration in chronic otitis media with effusion. Clinical and technical considerations

OBJECTIVE: To describe the patient, disease and clinical characteristics that optimize the effectiveness of laser tympanic membrane fenestration (LTMF) to treat chronic otitis media with effusion (OME). SETTING: Four pediatric otolaryngology tertiary referral centers. IRB approved; participation by informed consent. METHODS: An observational clinical effectiveness trial was conducted in 164 ears (94 children), who had chronic OME. All patients were candidates for insertion of pressure equalization tubes (PETs) but agreed to undergo LTMF instead. Clinical and audiologic follow-up are reported at 90 days after LTMF. OUTCOME MEASURES: Clinical effectiveness was defined as an effusion free middle ear at otoscopy with A or C1 tympanogram and normal hearing. RESULTS: At 90 days, 66% of the 95 evaluable ears were effusion free, all with normal hearing. Children younger than 4 years (P<0.04), who had shorter durations of effusion (P<0.009), and who experienced longer duration of fenestration patency (FP) (P<0.009) correlated to improved outcomes. CONCLUSIONS: The use of LTMF to create 2--3 weeks of middle ear ventilation in patients with chronic OME (middle ear effusion (MEE) for 3 months or greater) is effective in 66% of 95 (58%) of ears evaluable at 90 days follow-up. This study provides basic information needed to optimize the use of LTMF today and enhance research efforts in the future.     

Long-Term Middle Ear Ventilation

Successful long-term middle ear ventilation was established in 12 patients with chronic eustachian tube hypofunction that had failed to respond to repeated myringotomy and tympanotomy tube insertions by conventional techniques. The 12 patients (13 ears) had insertion of an untrimmed large flange “Per-Lee” type tube through a posterior-inferior tympanomeatal flap approach. The flange extended under the long process of the malleus, and into the hypotympanum and middle ear opening of the eustachian tube. The stem of the tube was brought out through the inferior central pars tensa. All tubes have remained in place for more than three years without serious complications providing adequate middle ear ventilation and preventing adherence of the tympanic membrane to the promontory.