Factors affecting recovery of mastoid aeration after ear surgery.

Fifty-six patients after tympanomastoid surgery were examined to determine recovery of mastoid aeration and various pre- and intraoperative factors such as eustachian tube (ET) function, how the mastoid mucosa had been treated during surgery and whether or not a large silastic sheet had been placed in the middle ear or a ventilation tube used. Mastoid aeration recovery was confirmed by computed tomography in 27 of the 57 cases (47%) within 12 months of surgery. Among the factors examined, preservation of the epitympanic mucosa was found to be most important in mastoid aeration recovery. Use of a large silastic sheet to cover the area from the bony ET and tympanic cavity to epitympanum, aditus ad antrum or antrum was found to be of some help in recovery mastoid aeration after complete resection of the mucosa and mastoid air cells. Preoperative ET function, anterior tympanotomy and use of a ventilation tube did not influence recovery.