Eustachian Tube Ventilatory Function Research Articles

Normal and abnormal middle ear ventilation.

Studies in infants and children have suggested a functional rather than mechanical obstruction of the Eustachian tube as a predisposing factor in middle ear effusions (MEE). To simulate this condition in the laboratory, an animal model was prepared using juvenile Rhesus monkeys. The tensor veli palatini muscle was transected or expunged posterior to the hamulus of the medial pterygoid lamina. Transection of the muscle resulted in negative middle ear pressure without effusion, whereas when the muscle was expunged, the animals developed a brief episode of negative middle ear pressure followed by a persistent MEE that was sterile for bacteria. An acute bacterial MEE developed following instillation of Streptococcus pneumoniae into the nasopharynx of animals that had had a previous unilateral transection of the muscle. The condition of the middle ear was documented by impedance measurements and presence of the effusion was verified by myringotomy. Animals were periodically examined and tested for Eustachian tube ventilatory function over a period of one year. Before surgical alteration of the tensor muscle. Eustachian tube function tests demonstrated normal ventilatory function, whereas, functional Eustachian tube obstruction patterns similar to studies in children who had MEE were found during the postoperative period. Only after the development of a reliable animal model can current and future methods of management of MEE be tested under controlled laboratory conditions. These data suggest that the Rhesus monkey appears to be an excellent model for the study of normal as well as abnormal tubal function.

Eustachian tube ventilatory function in relation to cleft palate.

The ventilatory function of the Eustachian tube was assessed in a group of infants and children with cleft palate, some of whom had received palatal repair. Those whose palates had been repaired were better able, in general, to equilibrate applied positive middle ear pressures than were those with open clefts. In many of the patients whose palates had been repaired, the results of Eustachian tube function studies were similar to those in normal subjects. Differences in Eustachian tube ventilatory function are assumed to be related to differences in tubal compliance. Excessive compliance probably results in, or exaggerates, functional Eustachian tube obstruction. Improvement in tubal function following palate repair is probably related to factors resulting in greater tubal stiffness.