Eustachian tube bypass: experimental evidence for total eustachian tube substitution.

Several preliminary reports have appeared in the medical literature in respect to eustachian tube substitution since Zollner first described his inability to open the obstructed eustachian tube. These procedures have the disadvantage that the distal end of the eustachian tube subsitute is inaccessible by other than another operation. This paper is follow-up report to our clinical experience. The purpose of the experiment was to determine whether the middle ear was ventilated by the tympano-oropharyngeal substitute eustachian tube and whether ascending infection occurred. Fourteen ears underwent eustachian tube substitution. The natrual eustachian tubes of these ears were obliterated three to five months after eustachian tube substitution had been performed. The animals were killed three to four months after obliteration of the natural eustachian tubes. Studies of the decalcified sections showed an absence of infection in six of the ears, with mild to severe inflammation in the rest of the specimens.