The effect of tonsillectomy on impedance audiometry.

In an experimental group of 22 patients undergoing elective tonsillectomies and having normal preoperative middle ear function, there is a significant development of abnormal tympanogram types, loss of crossed acoustic reflexes, and decrease in middle ear compliance on the first postoperative day when compared to a control group. Postoperative recovery of middle ear function begins at one week and is usually completed by one month. The loss of acoustic reflexes occurs in those patients with extreme changes in compliance and abnormal tympanogram types. The authors postulate that these changes in middle ear function in the immediate posttonsillectomy period might be due to the surgical disturbance of the peritubal lymphatic drainage, causing engorgement of the tympanic and tubular mucosa; and to abnormal swallowing with impaired coordination of the nasopharyngeal and tubal musculature. These data are helpful in investigating the tonsillar effect on middle ear function and disease.