[The condition of the Eustachian tube and its influence on the middle ear].

Any functional disturbance in the auditory tube may be documented morphologically. We demonstrated in case of a block changes within the tubal mucosa and in the adjacent salivary glands. Complete obliteration of the lumen is a very rare instance caused only by severe trauma or as a possible result of heavy inflammatory damage to the mucosa. A lack of ventilation produces in the tympanic cleft a vacuum, followed by a typical effusion out of the altered mucosa. Anaerobic conditions favour hyper and metaplastic transformation of the epithelium. The clinical picture resembles the non-purulent, closed form of otitis, serous otitis media. The missing clearance makes the discharge within the tympanic cleft a great challenge to the mucosa. Granulation tissue proliferates, an enzyme production is initiated and phagocytes help to eliminate or to organize the middle ear content. The clinical picture corresponds to otitis media adhaesiva. If the auditory tube is blocked long enough, the healing result leads to the atelectatic tympanon caused by scare tissue, dystrophic calcification, fatty degeneration of granulation tissue, fibrocystic transformation of the mucosa. The ossicular chain, if not destroyed or interrupted, is fixed. A very dangerous condition is caused by retractionpockets within the ear drum membrane. They give rise to secondary acquired cholesteatoma. In the beginning of the whole process we see the nonfunctioning auditory tube, provoked by an infection. The development of the tubal tonsil and the perivascular aggregations of immunocompetent cells lead to the opinion, that the tube is an immunological not only a mechanical barrier against ascending infections. Favoured by antibiotic treatment the inflammation is localized by the body's own defence within the tympanic tube and causes the blockage, the loss of function, which influences heavily the middle ear and its lining.