末梢型外傷性脳動脈瘤

TRAUMATIC ANEURYSM OF PERIPHERAL CEREBRAL ARTERY

I．はじめに

　脳動脈瘤の発生の原因としては，先天性，細菌性，動脈硬化性，外傷性などがあげられている。これらのうち，種々なる頭部外傷に起因する外傷性脳動脈瘤は比較的少ないものとされている。しかしながら，この外傷性脳動脈瘤は頭部外傷後，ある期間をおいてからdelayedhemorrhageを招くことがしばしばあり，しかもいつたん破裂するとその死亡率は高いとされており^1,5），発生頻度は低いとしても，頭部外傷後の合併症として重要な位置をしめるものといえよう。

　この外傷性脳動脈瘤の発生は，内頸動脈，あるいは硬膜動脈などに多くみられているが，前，中，後大脳動脈などの領域に発生する脳動脈末梢型の外傷性動脈瘤は比較的少いといわれている。

Two cases of traumatic aneurysm of peripheral cerebral artery were reported.

Case 1. A 6-year-old girl was severely injured on her head by automobile accident. Plain skull films showed depressed fracture in the left frontal region. Left common carotid angiogram 25 days after the injury revealed small aneurysm of a cortical branch of the anterior cerebral artery. Cranioplasty and removal of the aneurysm was performed. Postoperative course of this patient was uneventful.

Case 2. A 4-year-old girl fell downstairs and struck her left temporal region. On admission, she was unconscious and plain skull films showed multiple linear fractures. No aneurysm was demon-strated in the right common carotid angiogram immediately after the head trauma. Since her general condition gradually improved, she dis-charged 23 days after the head trauma.

63 days after the injury, she developed sudden onset of severe headache, vomiting, and status epi-lepticus. Right common carotid angiogram showed a large aneurysm arising from a branch of right pericallosal artery at the free edge of the falx. Parent artery of the aneurysm was clipped. Posto-peratively, the patient made uneventful recovery.

60 repoted cases of traumatic aneurysm of peri-pheral cerebral artery were reviewed and analyzed in etiology, diagnosis, clinical course, treatment and pathogenesis.