前交通動脈瘤症例に対するInterhemispheric Approachと Pterional Approachの治療成績の比較検討

Evaluation of the Surgical Results of the Interhemispheric Approach in comparison with the Pterional Approach for Anterior Communicating Artery Aneurysms

I．はじめに

　前交通動脈瘤は，解剖学的に①正中線上で深部にある点，②親動脈として左右の前大脳動脈A1より血流を受ける点，③動脈瘤周囲に主要な血管（左右の前大脳動脈A1，A2，Heubner動脈，穿通枝動脈など）がある点，④前交通動脈自体に奇形を含めvariationが多い点，などからその直達手術は脳動脈瘤手術の中でも難易度の高いものの一つである^7,8）．

　前交通動脈瘤に対する到達法は，昔からいくつかの方法が先人達によって行われてきたが，現在一般的に行われている手術法は，pterional approach^9）interhemi—spheric approach^6）の二つの方法である．両者とも利点，欠点がありどちらの方法が優れているかは一概には決めがたい問題である，成書にはそれぞれの利点欠点が個々に書かれているが，同一施設で両手術法の手術成績を比較検討したrelxortはわれわれが渉猟しえた範囲では見あたらなかった．そこで，われわれは過去5年問に当施設で経験した前交通動脈瘤症例に対するこれら二つの方法の手術成績を比較検討してみたので報告する．

From 1986 to 1990, 77 cases of ruptured anterior communicating artery (Aco) aneurysms have been operated on through an interhemispheric approach or a pterional approach.

In this study, we mainly investigated the following factors : surgical outcome, surgical complications, de-gree of evacuation of subarachnoid clot, and frequency of symptomatic vasospasm.

The difference of outcome between the two surgical groups was not statistically significant.

Each operating method had characteristic surgical complications. Pterional approach had a tendency to complicate premature rupture, sacrifice small vessels around the aneurysm, and to result in Korsakoff syn-drome and inadequate clipping. Interhemispheric approach was apt to complicate cerebral contusion, bi-lateral olfactory nerve injury and hemorrhagic infarc-tion clue to sacrifice of the bridging veins.

The pterional approach could evacuate more of the subarachnoid clot than could the interhemispheric approach, but there was no significant difference in fre-quency of symptomatic vasospasm depending on which method was used.