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

Abstract

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

Audiometric Outcomes and Middle Ear Disease following Cerebrospinal Fluid Leak Repair

“…15,16 Adequate ventilation of the middle ear cleft involves a complex network of pathways and gas pressure exchange mechanisms that, when disturbed, can allow for the development of chronic ear disease. 17 Undergoing repair may potentially disrupt this system from placement of graft materials obstructing the attic, postsurgical inflammation and scar formation, and drilling of the mastoid gas exchange system. For instance, if postoperative fibrosis obstructs the isthmus in the presence of a complete tensor fold, 18,19 there is significant disturbance in epitympanic ventilation even in the presence of normal eustachian tube function.…”

Otitis media with effusion in adults with patulous Eustachian tube

“…Dilatory ET dysfunction may be due to negative pressure in the middle ear cleft. 15 Although the etiology of OME is believed to be multifactorial, ET dysfunction is thought to be one of the most important reasons responsible for development of this disease. Dilatory ET dysfunction has been characterized as an important factor in the pathogenesis of OME.…”

On the functional compartmentalization of the normal middle ear. Morpho-histological modelling parameters of its mucosa

“…For instance, models of gas exchange have often used the traditional ME compartments of TC and MACS, while assuming a uniform histo-morphology (Ar et al, 2007;Doyle, 2017;Fink et al, 2003;Kania et al, 2004;Kanick et al, 2005;Swarts et al, 2010) and approximating the ME diffusion distance to the thickness of the promontory mucosa (Ar et al, 2007;Kanick et al, 2005;Yoon et al, 1990). In constructing such models, we need to know more about regional variations in the blood vessel density, diffusion distance, mucosa thickness, density of the lamina propria, and the surface area of active mucosa (Alper et al, 2017;Doyle, 2017;Marcusohn et al, 2010;Swarts et al, 2010).…”