内頚動脈周囲の強固な癒着により，頚動脈内膜剝離術を断念せざるを得なかった内頚動脈狭窄症の1症例

A Case of Internal Carotid Artery Stenosis with Discontinuance of Carotid Endarterectomy due to the Tight Adhesions around the Internal Carotid Artery

Ⅰ．はじめに

　頚部放射線治療や頚部手術の既往のある内頚動脈狭窄症は，ハイリスク群に分類されるため頚動脈内膜剝離術（carotid endarterectomy：CEA）の適応にならないとされている⁸⁾．

　今回われわれは，頚動脈壁と周囲軟部組織との強固な線維性癒着のため，CEAを断念せざるを得なかった内頚動脈狭窄症の1例を経験した．本症例には頚部の放射線治療や手術歴はなかったが，27年間に及ぶ繰り返す慢性中耳炎と，4回に及ぶ鼓室形成術の手術歴があった．そのため，慢性中耳炎からの炎症の波及が，頚動脈周囲の強固な線維性癒着の原因となったと考えられた．われわれの知り得た範囲では，このような長期間に及ぶ耳鼻科疾患の既往をCEAハイリスク群とした報告はなく，きわめて稀な症例と考えられたため，文献的考察を加え報告する．

　A 73-year-old female visited her local doctor after repeatedly experiencing temporary weakness in her left upper and lower extremities. The patient underwent a cervical magnetic resonance imaging (MRI) scan and was diagnosed with right internal carotid artery stenosis. Despite administration of antiplatelet drugs,her symptoms continued,and she was referred to our department for medical treatment. Her medical history revealed hypertension,hyperlipidemia,and cholesteatoma. We diagnosed symptomatic internal carotid artery stenosis and performed carotid endarterectomy (CEA). However,tight adhesions between the carotid artery and surrounding tissue made separation difficult,and surgery had to be discontinued. Some of the extracted adherent tissue consisted of hyalinized fibrous tissue that had the appearance of soft tissue which had organized because of inflammation. Although there have been no reports of cholesteatoma directly causing adhesion around the internal carotid artery,it has been reported to have led to abscess formation in the parapharyngeal space adjacent to the carotid space. Because the boundaries of the parapharyngeal space and carotid space are anatomically incomplete,inflammation often affects the area between them. As far as we know,this report,which also includes a discussion of the literature,is the first to indicate that cholesteatoma causes strong adhesions around the carotid artery.