小児滲出性中耳炎におけるatelectatic earの経過

Clinical Course of Atelectatic Ears in Children

I．はじめに

　小児滲出性中耳炎の病変に起因する中耳，および鼓膜のさまざまな病的変貌のうち，特徴的な1つの変化としてatelectatic earが見られる。atelectatic earについて，Sade^1）は鼓膜が岬角に近づいた状態と簡潔に記載している。典型的な小児のatelcctasisでは鼓膜の菲薄化が著明で，水に濡れた和紙のような外観を呈し，切開を行うと切開創は哆開し易い（図1）。

　これらの変化は中耳腔および耳管の病変を反映するもので，滲出性中耳炎の病態やその経過を理解する上に大切な変化と考えられる。しかし，この病変が滲出性中耳炎の経過途上のどの位置に位し，その後どのような経過をたどるのか，詳細は明らかでなくその病因に関する疑問の他に臨床的見地より次の問題が不明瞭なまま残されている。

　In 120 children who required tympanostomy tube insertion for treatment of serous otitis media during the past five years, the authors found 44 atelectatic ears beyond stage 2 after Sade's classification in 25 children, and followed up these children for 1/2 to 5. 1/2 years (mean duration, 2 years and 4 months).

　Atelectasis of the middle ear often associated with atrophy of the drum was seen in 27 ears (61%) without previous tube insertion and in 13 ears (30%) with previous insertion, which would suggest that atelectasis and atrophy are the results of the disease per se rather than tube insertion.

　The mean duration of intermittent hearing loss in children with atelectasis prior to operation was 14 months. Atelectasis may be considered as a chronic stage of otitis media with effusion.

　Except for 30 dB conductive loss at the low frequency range seen in two cases with cleft palate, no serious complications such as severe hearing impairment, adhesive otitis or cholesteatoma were seen in the series. For clinical purposes, atelectasis can be classified into two large categories, namely, atelectasis with effusion (wet atelectasis) and atelectasis without effusion (dry atelectasis) based upon the presence or absence of effusion.

　Atelectasis with effusion is the active stage of secretory process and atelectasis without effusion is its sequelae. Atelectasis with effusion is subdivided into grade 1 to grade 4 after Sadé and atelectasis without effusion may be into 4 grades; grade 1 with atrophy, grade 2 with tympanosclerosis, grade 3 adhesive otitis and grade 4 cholesteatoma.