[Progress in middle ear dysventilation research].Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2019 Apr 07; 54(4):303-306.ZE
Disfunction of Eustachian tube will cause negative pressure of middle ear, which may result in tympanic membrane retraction pocket. Severe pocket can consequently cause cholesteatoma. In clinical practice it is not uncommon to find a cholesteatoma limited to epitympanum, with an otherwise normal pars tensa and mesotympanum. This review explains the theory of "selective epitympanic dysventilation syndrome" developed by endoscopic technique. In the majority of the patients, the only ventilation pathway to the epitympanum is through the tympanic isthmus. Even if Eustachian tube function has recovered, an isthmus blockage with selective epitympanic dysventilation may lead to common attic cholesteatoma.