70歳以上の高齢者の未破裂動脈瘤の手術適応と問題点

Surgical Indication and Problems of Patients Aged over 70 Years with Unruptured Aneurysms

I．はじめに

　1997年5月に日本脳ドック学会から出された脳ドックのガイドラインでは70歳以上の高齢者の未破裂脳動脈瘤を手術することは積極的に勧められていない^2）．1996年までわれわれの施設でも70歳以上の未破裂脳動脈瘤の手術適応は本人の意思に任せてきた．しかし高齢であるとの理由で手術せずに外来で経過観察していた未破裂脳動脈瘤の76歳女性が，脳動脈瘤が発見された8カ月後の1996年5月に重度のくも膜下出血で搬入されるという非常に苦い経験をした．それ以来当科では70歳以上の未破裂脳動脈瘤でも重篤な基礎疾患あるいは高度の脳血管障害の既往を有しない場合には根治術を考慮すべきであるという方針を取ってきた．

　今回市立函館病院脳神経外科で経験した70歳以上の未破裂脳動脈瘤18例の予後から，高齢者の未破裂脳動脈瘤の手術適応と問題点について検討したので報告する．

Surgical indication and problems of patients aged over 70 years with unruptured aneurysms were investi-gated.

Clinical features of eighteen cases of unruptured cerebral aneurysms were analyzed. The location of thecerebral aneurysms were in the internal carotid artery in five cases, in the middle cerebral artery in tencases, in the anterior cerebral artery in 2 cases and in the basilar artery in 1 case. The size of the aneu-rysms was less than 10mm in diameter in 17 cases and giant in one case.

Treatment of these aneurysms was classified into two groups as follows; the conservative treatmentgroup (four cases) and the surgical treatment group (14 cases). The therapeutic results of the conservativegroup were good recovery in 2 cases, and death in 2 cases. On the other hand, the results of surgical groupwere good recovery in 12 cases and fair in 2 cases. Operative complications were recognized in two cases.Consciousness disturbance and left hemiparesis was recognized in one case. Right hemiparesis was recog-nized in the another case. Postoperative MR imagings or CT scan presented small cerebral infarctions inthe corona radiata in both cases. The cause of infarction was thought to be the occlusion of lenticulostriatearteries.

From these data, in patients aged over 70 years with unruptured cerebral aneurysms, surgery should beconsidered not only from the aspect of aneurysmal size and its site, but also from the aspect of cerebralblood flow of the patient.