Classification of pathological epidermization (cholesteatoma) of the middle ear NMAO

Abstract

The periodicals published over the past 5 years showed that interest in the issue of surgical treatment of chronic otitis media, including one complicated by cholesteatoma, did not wane despite the large accumulated experience of schools in otosurgery around the globe. In our opinion, there are currently some significant problems of terminology in the clinical anatomy of the ear, in particular, the nomenclature of the upper floor of tympanic cavity, which negatively affects the comparison and reproducibility of the results of surgical treatment of chronic otitis media. The critical analysis of the current classification of middle ear cholesteatoma proposed in 2017 and validated in Russia in 2021 demonstrates certain difficulties in using the pathohistological term “cholesteatoma”, as well as the basic inaccuracy in defining the concept and structure of the anterior parts of the epitympanum. The work aims to develop and present a new classification of pathological middle ear epidermization (cholesteatoma), which is based on the pathophysiology of middle ear ventilation. The modern concepts on the mechanisms of middle ear ventilation reveal its important role in developing the pathological epidermization and secondary cholesteatoma. The use of three-dimensional modelling of airway ventilation makes it substantially easier to follow the pathophysiological mechanisms of development of tympanic membrane retraction. The tympanic diaphragm consists of more than 10 composite elements. Understanding the pathophysiological principles underlies the proposed classification of pathological middle ear epidermization (cholesteatoma), which is based on the prevalence of middle ear and surrounding anatomical formation injuries. The pathological process area is coded using the abbreviation of the National Medical Association of Otorhinolaryngologists. In this abbreviation, each letter corresponds to a specific anatomical region. The tympanic diaphragm represents the boundary between the regions. Each letter is assigned an index corresponding to the degree of pathological epidermization invasion into the structures of the middle ear, temporal bone and cranial cavity. The authors provide a table, which serves as a visual aid for ease of coding the diagnosis. Examples of how to formulate a diagnosis in accordance with otoscopic illustrations are given.