PTCA後左主幹部狭窄の進行を認めた1例

Acceleration of the left main coronary artery stenosis following PTCA:A report of a case

　PTCA（経皮的冠動脈形成術）は虚血性心疾患に対する有力な治療法として現在多数の施設で行われており，器具の進歩や術者の熟練に伴い合併症の頻度も減少してきている^1,2）。今回我々は左前下行枝病変にPTCAを施行した6カ月後の造影にて左主幹部に新たに有意狭窄を認めた症例を経験した。我々が調べ得た限りでは本邦では同様の報告はなく，まれではあるが重大なPTCAの合併症と考えられたので報告する。

Acceleration of the left main coronary artery (LMCA) stenosis induced by guiding catheter which was used for percutaneous transluminal coronary angioplasty (PTCA) was demonstrated in a 68 years old man with post-infarction angina. He underwent PTCA to a subtotal lesion in the left anterior des-cending coronary artery (LAD). The LMCA with mild stenosis of 18% reduction of luminal diameter was unchanged during the course of PTCA. The guiding catheter was pushed repeatedly with consi-derable force for introducing balloon catheter due to the rigid lesion in LAD. Progression of the LMCA stenosis to a 64% was demonstrated at 6 months later angiographic restudy. It was conside-red that repetitive sliding of guiding catheter through the LMCA caused subangiographic intimal trauma and facilitate subsequent progression of ste-nosis. We examined the guiding catheter to the LMCA diameter ratio, the angle of the tip portion of the guiding catheter with LMCA, and severity of the target lesion in this case compared with other 27 controls in whom PTCA was performed to the lesion in left coronary artery. No difference of these 3 factors between this case and other 27 cont-rols was obtained. Thus it might be difficult to predict progression of LMCA stenosis by these an-giographic factors. Although the incidence of cathe-ter-induced progression of LMCA stenosis was as low as 1 of 160 cases (0.6%) in our experience, it is important to attend to catheter-induced progres-sion of LMCA stenosis and to make an early detec-tion.