内頸動脈後交通動脈分岐部の血管膨隆病変—血管写所見及び術中所見からの検討

Dilated Lesion at Internal Carotid Artery Posterior Communicating Artery Junction

I．はじめに

　最近は未破裂動脈瘤に対して，積極的に手術が行われている機会が多い^1-3）．しかし，脳血管写上内頸動脈後交通動脈（IC-PC）分岐部に見られる血管膨隆に関しては，これが真の動脈瘤（AN）であるのか否か診断に苦慮する場合が少なくない．

　私達は，現在まで血管写上長径3mm以上のこの部の血管膨隆26症例28病変に対して外科的治療を行ったが，術中所見では真の動脈瘤は存在せず後交通動脈（Pcom）の起始部そのものが単に拡張しているに過ぎない症例を少なからず経験した．

　本論文では，これらの症例の術中所見と血管写所見を対比し，本病変の形態的特徴及び診断治療上の問題点につき検討した．

The diagnosis and surgical indication of an incidental aneurysm at the IC-PC junction is sometimes vague. In this report, 28 lesions in 26 cases with aneurysmal dilata-tion at the IC-PC junction, which were surgically treated, were analyzed. These lesions are classified according to the operative findings.

Only 6 of the lesions were confirmed to be true aneurysms. However, 19 lesions were the dilated changes of the posterior communicating arteries (Pcom) themselves, without aneurysmal formation. Two lesions were accompanied with blood blister like aneurysm at the wall. Another one was dilated Pcom with peripheral Pcom occlusion.

The correlation between operative findings and angiographic findings are studied, and the importance of the diagnostic angiographic findings of the Pcom is strongly emphasized for their diagnostic value.