Does Early Surgical Intervention of Middle Ear Atelectasis Improve Long-term Results and Prevent Cholesteatoma?

Atelectasis of the tympanic membrane (TM) is a frequently encountered otologic abnormality, yet the treatment of atelectasis remains controversial. This controversy stems in part from the fact that the term atelectasis may refer to a variety of conditions that have very different clinica l behav ior . Some authors differentiate fibroadhesive otitis media or retraction pockets from atelectasis, whereas Buckingham considered these conditions to be advanced stages of atelectasis. In addition, atelectasis of the pars tensa and pars flaccida clearly have different risks and surgical treatment. To evaluate clinical outcomes, Sade and Berco developed a separate staging system for pars tensa atelectasis that is widely used (Table). This grading system, however, does not account for the thickness of fibrosis or other factors that influence outcome, such as the degree of hearing loss or ossicular erosion. Atelectasis of the TM appears to be very common and may be asymptomatic. A survey of 1372 school children in Finland found retraction of the TM in 10% of 7-year-old children, with evidence of adhesion in 1.3%. In a long-term follow-up study of children 3 years after tympanostomy tube placement, Tos et al reported an initial finding of TM atrophy and adhesion (myringopexy) in 3% of patients, which increased to 5% of the subjects at the final follow-up visit 5 years later. Their detailed analysis revealed that patients who initially presented with atrophy and myringopexy may persist or progress to more severe stages of adhesive disease. Li et al reported an 8.9% incidence of severe atelectasis in 112 children followed after tympanostomy tube insertion. In a large series, Luxford and Sheehy also reported that atelectasis was the indication for tympanostomy in 3% of patients. The underlying disorder in atelectasis is eustachian tube dysfunction leading to retraction and atrophy of the TM with loss of the organized collagenous layer. This atrophy converts the middle ear into a collapsible compartment in response to only minor changes in middle ear pressure. Persistent eustachian tube problems may therefore lead to a recurrence of the disease after treatment. Once the TM is retracted onto the ossicles or promontory, it may become adherent to the underlying structures and lead to acquired cholesteatoma. The risk of cholesteatoma has been noted clinically in long-term follow-up studies of atelectasis. In their prospective study, Tos et al reported that 4% of 52 patients with TM atrophy developed attic cholesteatomas, and 1 case of a sinus tympani cholesteatoma was diagnosed among 10 patients with adhesive otitis media followed for at least 6 years. In another study of 39 patients with grade III atelectasis, most ears improved or remained stable without treatment, while roughly 10% deteriorated, possibly leading to cholesteatoma formation. In a review of his experience with 520 atelectatic ears including retraction pockets, Sade reported the eventual deterioration to cholesteatoma in 2% to 10% of ears. In addition to the risk of cholesteatoma, adhesion of the TM alone may lead to erosion of the ossicles. Thus, although atelectasis in itself is a benign disease, the potential risk of cholesteatoma or ossicular erosion has led many otologists to adJames E. Saunders, MD