冠動脈三枝慢性完全閉塞の成立条件—冠動脈閉塞部位と側副血行路との関係

The necessary conditions of chronic total occlusion of all three coronary vessels:the relationship between portions of coronary occlusion and collateral vessels

　【目的】三枝慢性完全閉塞にいたるには，冠動脈にいかなる条件が必要かを明らかにしたい。【対象】過去20年間に施行した約5,000例の冠動脈造影中，前下行枝，回旋枝，右冠動脈の三枝に慢性完全閉塞を示した5例。【結果および考案】側副血行路の供給枝は右室枝，中隔枝，左房回旋枝であり，冠閉塞部位は計15枝中13枝が冠動脈中間部であった。左心機能が良好な3例は，すべて中間部閉塞で良好な側副血行路を認めた。近位部閉塞の1例は高度の左心機能障害があり，経過中突然死した。狭心症の病歴が5〜21年と長期であったことは，側副血行路発達の要因になり得ると思われる。【結語】三枝慢性完全閉塞の発現条件は、①冠閉塞部位が冠動脈中間部より末梢に位置し，②右室枝，中隔枝，左房回旋枝など近位部分枝から良好な側副血行路が出ており，②狭心症の病歴が長いことなどが考えられた。

This study was performed to define the conditions present in chronic total occlusion of all three coro-nary vessels.

Each left descending coronary artery (LAD), left circumflex branch (LCX) and right coronary artery (RCA) was totally occluded angiographically in 5 patients (mean age 64, male 3, female 2).

Four of them had history of myocardial infarction. Anginal type was effort angina in all patients, and two cases showed unstable angina.

Good collateral supply was found in the distal por-tions of occluded vessels from proximally located branches, such as Conus branch, Right ventricular branch, Septal branch and Left atrial circumflex branch. Almost all of the occlusions were located at mid portions (13/15: mid, 2/15: proximal). Ejec-tion fractions (EF%) of the 5 patients were 70%, 69 %, 60%, 28% and 22% respectively. EF was corre-lated with the degree of collateral supply and one of them (22%) ended in sudden death.

These findings suggest that the mid portion occlu-sion, good collateral supply and a long history of angina pectoris are important factors involved in chronic total occlusion of the three coronary vessels.