Eosinophilic otitis media diagnosis using flow cytometric immunophenotyping

Objectives: (1) To assess the ability of flow cytometric immunophenotyping to detect and quantitate eosinophils in patients with eosinophilic otitis media (EOM). (2) to evaluate the association of EOM to bronchial asthma.

Methods: Twenty-one patients with chronic otorrhea or middle ear effusion (MEE) were included in this prospective cohort study. Group I composed of 10 patients (14 ears) and associated to bronchial asthma. Group II included 11 patients (11 ears) without bronchial asthma. Samples of MEE were sent for flow cytometric analysis at initial presentation. Patients with positive eosinophils on flow cytometric immunophenotyping were analyzed after one-month course of dexamethasone eardrops.

Results: EOM was diagnosed in all patients of group I and in three patients of group II. The mean eosinophils percentage was 43.5% and 14.2% for group I and group II, respectively (p?=?.006). Those patients showed a significant response to dexamethasone eardrops, both on clinical examination and on flow cytometric analysis with a decrease in eosinophil levels post-treatment. However, this improvement was temporary and symptoms recurred after treatment cessation. Bronchial asthma was not associated to all patients with EOM.

Conclusion: Diagnosis of EOM remained mostly clinical; flow cytometry immunophenotyping of MEE may be helpful as an additional tool in diagnosis and monitoring the response to treatment, particularly in non-asthmatic patients.     

Gastroesophageal reflux and sequelae of chronic tubotympanal disorders in children

Objective—To compare sequelae of chronic tubotympanal disorders in children with and without gastroesophageal reflux (GER).

Material and Methods—In 32 patients with chronic tubotympanal disorders GER was studied by means of 24-h continuous esophageal pH monitoring. After a period of 2–6 years (mean 4 years) sequelae of the tubotympanal disorders were examined, together with the clinical status of the ears and hearing status. The criteria for classification into mild, moderate and severe sequelae were based on the clinical status of the ear. Hearing was determined using tonal audiograms. Conductive hearing loss was classified as either slight (≤ 35 dB hearing loss in speech frequencies) or severe (>35 dB hearing loss in speech frequencies).

Results—In the group of 16 patients (mean age 6.1 years) with GER, sequelae were observed in 29 ears (mild, n=11; moderate, n=5; severe, n=13). Hearing impairment was determined in 20 ears (mild, n=8; severe, n=12). In the group of 16 patients (mean age 7.1 years) without GER, sequelae were observed in 17 ears (mild, n=11; moderate, n=1; severe, n=5). Hearing impairment was determined in 10 ears (mild, n=6; severe, n=4).

Conclusion—The total number of ears with sequelae and the total number of ears with conductive hearing impairment were significantly higher in patients with GER.     

Prediction of gastroesophageal reflux in otitis media with effusion in adults

Conclusions. The measurement of pepsinogen I (PGI) in middle-ear effusions (MEEs) and a questionnaire on the frequency symptoms of gastroesophageal reflux (GER) disease are tools that can be used to screen for the existence of GER. Objective. To seek methods that would be beneficial as a screen for the presence of GER among adult patients with OME. Materials and methods. Fifty-eight adult outpatients with OME were asked to answer a questionnaire of the frequency scale for symptoms of GER disease. Samples of MEEs were obtained from each subject and were measured for concentrations of PGI and PGII. Some patients were followed up after being treated with a proton pump inhibitor. Results. The percentage of patients with high PGI concentrations in their MEEs was higher in those with GER-related symptoms than in those without GER-related symptoms. Moreover, OME was present bilaterally in a higher percentage of patients with GER-related symptoms. There were patients in whom PGI levels decreased after receiving treatment for GER.     

Technical pitfalls in middle ear gas studies: Errors introduced by the gas permeability of tubing and additional dead space

Conclusions We demonstrated errors introduced by the gas permeability of the tubing and additional dead space. Materials with practically no permeability, such as glass, must be used to overcome the loss or gain of gas through the walls of tubes used for studying ME gas variations. Experiments conducted at a constant volume (variable pressure) require the smallest possible tubing volume in order to obtain good sensitivity and improve the accuracy of the results.

Objectives Experimental studies that investigate middle ear (ME) gas exchanges, using either pressure measurements or volume changes, are conducted using various tubing connections between the ME and a measuring device. The aims of this study were to highlight experimental problems due to the errors introduced by (i) the gas permeability of the tubing used and (ii) additional dead space in experiments conducted at constant volume.

Material and methods The problem of the gas permeability of the tubing was addressed by comparing three types of tube (silicone, polyethylene, PVC) with a glass tube. Horizontally placed tubes were connected to a syringe filled with pure CO₂ via a gas-tight valve. The end of each tube tested was plunged into colored water (5% Coomassie Brilliant Blue R-250). The tube was washed out with CO₂ until gas bubbles were seen leaving it. The valve was then closed and the movement of water in the tube was observed. The same experiments were repeated for pure O₂. The problem of the error introduced by the additional dead space volume was addressed at a theoretical level using the well-known gas laws. Two conditions were studied: condition A, in which the experiment was conducted at constant pressure and the volume was measured; and condition B, in which the experiment was conducted at constant volume and the pressure was measured. The main outcome measure of each condition was the calculated variation in the final number of moles of gas involved.

Results No water movement was observed in glass tubes. In contrast, plastic tubes exhibited significant gas permeability effects for both CO₂ and O₂. The colored solution advanced at a faster rate with CO₂ than O₂ but differently for each type of tubing. For condition A, gas transfer was independent of the volume of the external tubing and was accurately measured by the displacement of the droplet in the lumen. In contrast, for condition B, the pressure variations were influenced by the volume of the tubing.     

Aquaporin-2 in the human endolymphatic sac

Objective To detect and localize aquaporin-2 (AQP-2), a water channel regulated by the antidiuretic hormone, in human endolymphatic sac.

Material and Methods Human endolymphatic sacs were sampled during removal of vestibular schwannomas via a translabyrinthine approach. Samples were immediately fixed in 10% formalin (24 h) and embedded in paraffin; in situ hybridization and immunohistochemistry were performed with an AQP-2-specific probe and a polyclonal antibody.

Results Both AQP-2 mRNA and protein were detected in the epithelium of the endolymphatic sac. AQP-2 immunostaining was mainly cytoplasmic, suggesting that most AQP-2 was located in intracellular pools.

Conclusion In the endolymphatic sac, AQP-2 probably participates in the homeostasis of endolymph; the possibility of reducing the volume of endolymph by inhibiting its expression and membranous insertion using an antidiuretic hormone inhibitor represents a new therapeutic approach for the treatment of Ménière's disease.     

Surgical anatomy and pathology of the middle ear

Middle ear surgery is strongly influenced by anatomical and functional characteristics of the middle ear. The complex anatomy means a challenge for the otosurgeon who moves between preservation or improvement of highly important functions (hearing, balance, facial motion) and eradication of diseases. Of these, perforations of the tympanic membrane, chronic otitis media, tympanosclerosis and cholesteatoma are encountered most often in clinical practice. Modern techniques for reconstruction of the ossicular chain aim for best possible hearing improvement using delicate alloplastic titanium prostheses, but a number of prosthesis‐unrelated factors work against this intent. Surgery is always individualized to the case and there is no one‐fits‐all strategy. Above all, both middle ear diseases and surgery can be associated with a number of complications; the most important ones being hearing deterioration or deafness, dizziness, facial palsy and life‐threatening intracranial complications. To minimize risks, a solid knowledge of and respect for neurootologic structures is essential for an otosurgeon who must train him‐ or herself intensively on temporal bones before performing surgery on a patient.