Valve section of the eustachian tube.

Research on the eustachian tube (ET) and related paratubal structures was carried out by serial section of the temporal bone-ET specimens. In the cadaveric studies, the mid-cartilaginous section of the ET presented a curved slit-like lumen. It is believed that this section functions principally as a valve mechanism and acts like an active sphincter of the ET. This report illustrates the dynamic movement of the valve section in a living ET which can be observed by using a superfine fibreoptic videomicroendoscope. Disorders of the open-close mechanism of the valve section in a diseased ET due to different aetiologies are also discussed. This study indicated that transtympanic ET microendoscopy had considerable potential for exploring fascinating new aspects of the physiology, pathophysiology and anatomy dynamics of the ET.