内頸動脈起始部に特異な病変を示したFibromuscular Dysplasia

Fibromuscular Dysplasia at the Internal Carotid Origin: A case of carotid web

I．はじめに

　Fibromuscular dysplasia（以下FMD）は，1938年に，Leadbetterら^10）により腎動脈撮影において初めて報告され以後頭頸部におけるFMDは欧米にて300以上を数えるに至った．しかし日本では比較的まれな病態で報告も少なく，30余例の報告のみである^15）．その好発部位は腎動脈がもっとも多く，ついで頭蓋外内頸動脈，椎骨動脈とされており，内頸動脈の病変は第2頸椎の高さに圧倒的に多い．今回われわれはTIAにて発症し，内頸動脈起始部に，“web shape”を示した狭窄性病変を認め，病理所見からFMDと判明した1例を経験した．本邦での報告はいまだみられず，文献的考察を含めて報告する．

A case of fibromuscular dysplasia at the internal carotid origin is reported.

A 45-year-old, right-handed woman who was in good health, experienced 5 - 6 second episodes of numbness and tingling in her right hand and lip. She had no history of medical illness or trauma.

The patient suffered the same sort of attack almost seven years after her first episode.

General examination was unremarkable. There was no sign of residual neurologic deficit. Cerebral angiography demonstrated a discrete filling defect at the internal caro-tid coign. There was no evidence of atherosclerosis in the intracranial or extracranial vessels. The lesion occluded approximately 58% of the lumen. A carotid endar-terectomy was performed and a web shaped' tissue was removed from the posterior aspect of the right inter-nal carotid artery. Microscopic examination of the sur-gical specimen demonstrated intimal fibrosis, consistent with the diagnosis of fibromuscular dysplasia. In addition to our patient, eight other cases of cephalic fibromuscular dysplasia have been reported in the form of an internal carotid web. This type of lesion is unique because the changes involve only the intima of the ves-sels without involvement of the medial structure as is seen in the usual form of fibromuscular dysplasia. Moreover, 5 out of 9 patients reported had the repeated episodes of the ischemic symptom, suggesting patients with this particular lesion have higher risk for stroke than those with the usual “string of beads” lesion. In these pa-tients, surgical treatment should be considered, especial-ly if medical therapy is unsuccessful.