超選択的局所線溶療法が有効であった左房内粘液腫による中大脳動脈塞栓症の1例

Superselective Fibrinolysis for a Middle Cerebral Artery Embolism Caused by a Left Atrial Myxoma : case report

I．はじめに

　脳主幹動脈閉塞症，特に中大脳動脈閉塞症（MCAO）に対する治療法として超選択的局所線溶療法（LIF）が行われ，その有用性が報告されている^2,3,21）．

　今回われわれは，左房内粘液腫によるMCAOに対しLIFを施行し再開通を得た症例を経験したが，粘液腫による脳塞栓の原因として腫瘍周囲に付着した血栓，また腫瘍そのものによる場合の2つが考えられる．現在までに左房粘液腫による脳塞栓は多くの報告がみられるが^{4,6-9,11,13,15,16,19，23）}，LIFを行った報告は少な^13），粘液腫に起因する脳塞栓に対する治療法についても考察を加え報告する．

A case of successful treatment by local fibrinolysis of a middle cerebral artery embolism caused by a thrombus from a left atrial myxoma is reported.

A 62-year-old woman using a pacemaker and suffering from sick sinus syndrome was admitted on De-cember 29th 1996, complaining of transient restlessness. CT and cerebral angiography revealed no abnor-mal vascular lesions. Eighteen months after the initial episode, she suffered a sudden onset of left hemi-paresis and loss of consciousness. CT scan performed during the second episode revealed no lesions and, in particular, no early CT infarction sign, but emergent cerebral angiography revealed a right middle cerebral artery embolic occlusion. Local fibrinolysis using a tissue plasminogen activator was performed within 3 hours after the beginning of the episode, and partial recanalization was obtained within one hour after in-itiation of the fibrinolytic therapy. On the first hospital day, though CT revealed a small low-density area in the right basal ganglia, motor deficits gradually improved. Considering the possibility of a cardiac source of the embolism, trans-esophageal echocardiography was performed and revealed a left atrial tumor suspected to be a myxoma. It was removed by surgery on the 34th hospital clay. Histological examination proved it to be a myxoma. Nine months after local fibrinolytic therapy, the patient returned to work. The diagnosis of cerebral embolism caused by cardiac myxoma is difficult to make at the time when the patient is first examined after admission. It is also hard to discover during emergent cerebral angiography with fibrinolytic therapy. Therefore, in the case of patients with cerebral embolism for which local fibrino-lysis is ineffective, it should be presumed that cardiac myxoma is the source of the embolus. Direct PTA alone may be effective for such tumoral embolism.