鼓室成形術と術後性真珠腫—再手術例よりの検討

AN OCCURRENCE OF CHOLESTEATOMATA FOLLOWING TYMPANOPLASTY

　I．はじめに

　鼓室成形術の不成功例を再手術すると，術腔に真珠腫塊の見い出される症例がある。最初，それを取り残しにより生じた再発性真珠腫と考えていたが，形成部位が異常であつたり，また前回手術で真珠腫所見なしという症例もあつて，次第にこのような真珠腫の発生に疑いを抱くようになつた。一般には，すでにgraft cholesteatomaや，外耳道に開く巨大な術後乳突腔内での表皮増殖など，新たな真珠腫形成のあることが知られている。

　本論文は，このような鼓室成形術後に形成された真珠腫について，再手術時の所見をもとに種々考察を加えたものである。

　Seventeen cases of postoperative cholesteatoma that have undergone revision surgery are reported. On the basis of findings in the original surgery and the revision, the affections were classified as 11 cases of iatrogenic cholesteatoma, 4 recurrent cholesteatoma and 2 of residual cholesteatoma.

　Residual cholesteatomas were found to be the regrowth of the cholesteatomatous tissues which were left in the tympanic sinus at the time of the original surgery.

　A case of recurrent cholesteatoma occurred because of the retraction of the tympanic membrane into the tympanum following meatotympanoplasty. The other case of recurrency developed as a result of infections and reperforation of the tympanic membrane with continued Eustachian tube insufficiency.

　The iatrogenic cholesteatomas were found to be squamous cysts developing from the remnants of drum epithelium or the canal skin left behind the new ear drum. In 5 of these cases the reason for revision was a sudden and marked drop in hearing, which generally occurred in the 2nd year postoperatively. The others were revised because of graft failures.

　In all cases of revised operations there was no case of intracranial complication nor that of labyrinthine fistula.