Role of the mastoid in tympanic membrane reconstruction.

Otologists have long debated the importance of the mastoid in determining the success or failure of tympanic membrane reconstruction. The pneumatic spaces within the mastoid represent an "air reservoir" which can be drawn upon during periods of eustachian tube dysfunction and buffer the middle ear against the development of detrimental negative pressures. Mastoid inflammatory disease, if untreated, may result in recurrent suppuration and graft failure. Small mastoid volume, aside from its well known association with chronic infectious middle ear disease, has been shown to effect adversely graft survival following myringoplasty. In 48 patients undergoing myringoplasty with simple mastoidectomy, neither small mastoid size nor inflammatory mastoid disease significantly decreased the rate of graft healing. This suggests that simple mastoidectomy is an effective means of repneumatizing the mastoid and eradicating mastoid sources of infection. The successful surgical creation of a pneumatized mastoid cavity in communication with the middle ear was confirmed by postoperative computerized tomographic (CT) scans. In failed cases, CT scanning predictably identified residual mastoid disease. Simple mastoidectomy is considered to be a safe and useful adjunct to myringoplasty in selected cases of chronic otitis media with perforation.