重症高脂血症（タイプIIa，ホモ接合体）による若年者冠状動脈硬化症に対するA-Cバイパス手術の経験

Aortocoronary bypass surgery in an 18 year-old woman with severe hypercholesterolemia (Familiar hyperlipoproteinemia IIa, Homozygote)

　高脂血症は冠状動脈硬化症の重要なリスク因子でありヘテロ接合体家族性高脂血症を有する狭心症，心筋梗塞患者は比較的しばしばみられる。一方，ホモ接合体は稀であるがきわめて重篤な高脂血症を発生し若年のうちに高度の冠状動脈硬化症を来たしてくる^1）。著者らは家族性高脂血症タイプIIa，ホモ接合体患者で不安定狭心症を呈した18歳女子の1例に大動脈—冠状動脈バイパス移植術（A-Cバイパス手術）を行い，更に再発した狭心痛に対し再バイパス手術を行った。初回手術より1年8月，再手術より10ヵ月を経過した現在移植された2本の大伏在静脈グラフトは良好に開存し狭心痛は全く消失した。ホモ接合体家族性高脂血症に対するA-Cバイパス手術の報告は未だなく，その長期成績に関しては不明であるが本手術を行うことによって臨床的にきわめて良好な緩解を得ることができた症例を経験したので報告する。

An 18 year-old woman with severe hyper-cholesterolemia (1000 mg/dl) due to type IIa familiar hyperlipoproteinemia underwent double aortocoronary bypass surgery for unstable angina pectoris. Four months after the surgery, one of the saphenous vein grafts (LAD) became severely narrowed with resultant recurrence of angina which progressed rapidly. Re-grafting using the new saphenous vein was carried out with complete disappearance of angina again. Ten months after the second operation, both grafts to the LAD and RCA are patent and the patient is completely free from angina with no medications. The graft to the RCA has been well patent since the first surgery. The cause of the LAD graft stenosis was severe intimal-medial hyperplasia. No cholesterol deposit or foam cells were identified.

To our knowledge, no report has been made of surgical treatment for coronary artery disease due to severe hypercholesterolemia of homozygote type of hyperlipoproteinemia. Although there is no evidence that the surgery can improve the poor prognosis of this disease, it is apparent from our experience that the surgery can give an excellent amerioration of intractable angina pectoris. The effect of surgery is also evidenced by exercise EKG test and left ventricular function study during exercise.