経過観察中に動脈瘤が増大した細菌性脳動脈瘤の1例

Bacterial Intracranial Aneurysm Associated with Infective Endocarditis:a case showing enlargement of aneurysm size

I．はじめに

　われわれは，感染性心内膜炎が原因で発生した細菌性脳動脈瘤でその経過観察中に動脈瘤の径が増大した中大脳動脈末梢の部分的血栓性動脈瘤を経験した．細菌性動脈瘤は稀に経験する動脈瘤であるが本症例における動脈瘤の増大の機序，治療上の問題点等につき若干の知見を得たので報告する．

The authors report a case of bacterial intracranial aneurysm associated with infective endocarditis. A 48-year-old male was admitted on March 26, 1994, with complaints of difficulty in speaking and mild swelling of the right leg following mild fever. On examination he showed motor aphasia and mild weakness of the right upper and lower limbs. Cardiac auscultation re-vealed a grade 3/6 holosystolic murmur. Laboratory data revealed signs of infection through white blood cell count and CRP. Enterococcus faecalis was isolated from the blood culture at the time of admission. A com-puterized tomographic (CT) scan and magnetic reso-nance (MR) imaging showed a round mass with peri-f ocal edema. Angiography revealed an aneurysm from the precentral artery of the left middle cerebral artery. A mycotic aneurysm due to bacterial endocarditis was diagnosed. The patient was treated with high doses of antibiotics. However, angiography 2 weeks after the in-itial study demonstrated the enlargement of the aneurysm and severe narrowing of the angular artery. On April 19, excision of the aneurysm was performed. Operative findings showed degeneration and thickening of the walls of the aneurysm. After the operation, anti-biotic therapy was continued. The patient was asymp-tomatic upon discharge and has continued to do well. Repeated angiography on September 12 showed no further aneurysm.

There is a danger of rupture in mycotic aneurysm due to bacterial endocarditis. It is important to repeat angiography and to manage the primary disease. If an aneurysm enlarges with serial angiography, it should be treated surgically without further delay.