Structure and Healing Capacity of the Rat Tympanic Membrane After Eustachian Tube Occlusion

Abstract

Obstruction of the Eustachian tube in rats results in an accumulation of serous fluid in the middle ear cavity. the fluid was first detected in the attic, and subsequently the whole cavity became filled. However, when a perforation of the tympanic membrane was performed in connection with experimental tube obstruction, the mesotympanon was found free from fluid, but not the attic, as long as the perforation remained open. After 9-11 days of obstruction the pars flaccida was found to be maximally retracted, forming a non-adhesive clean retraction pocket. in addition, marked ultrastructural changes were found to have taken place in the pars flaccida following tube obstruction. Finally, in spite of the occluded Eustachian tube, traumatic tensa perforation was found to heal rapidly.