The infant's "post-isthmus" region of the eustachian tube in health and disease.

The size of the eustachian tube post-isthmic lumen in infants and children less than 2 years old is discussed. The material in our study consisted of serially sectioned eustachian tubes of twenty-six normal temporal bones and fourteen temporal bones harboring acute and secretory otitis media. The size of the eustachian tube lumen was measured with the aid of a millimetric grid mounted on a microscope. These measurements have shown that: There is no increase in the lumen size of the post-isthmic region of the eustachian tube from birth to 2 years of age. Each age group presents a considerable range in luminal area, compatible with the natural biologic distribution. No obstruction of the eustachian tube lumen was encountered in any of the pathologic specimens. There is no significant statistical difference between the lumen size of the post-isthmic region coming from normal temporal bones as compared with those from temporal bones with acute or secretory otitis media.