心臓カテーテル検査時の血栓形成および動脈壁損傷に関する実験的検討

Aortic wall injury and thrombogenesis in catheterization:Experimental study

　心臓血管カテーテル検査法は循環器領域において，頻回に行われている検査法であり，他の検査では得られない貴重な，多くの情報をもたらすことから，年々その件数は増加している。

　諸外国においては末梢の微細な塞栓症に至るまで数多くの合併症の報告^1）がみられるが，日本においては心室穿孔や大動脈解離といった重大な合併症以外は，問題として取り上げられていない。しかし，わが国においても検査数の増加に伴い，それに起因する合併症の発生も相次いでいるものと想像される。

Arterial and venous catheterization is a very useful procedure in the diagnosis of heart diseases. How-ever, some complications with thrombogenesis have been reported.

Two kinds of Mikaelson-type non-heparin-coated angiographic catheters (with 6. 5 Fr. and 80 cmlength) were used for the experiments. One was of polyurethane (PUC) and the other of polyethelene (PEC).

Eight experimental dogs were used for each group. The catheter was inserted into the ascending aorta through the femoral artery. No antithrombogenic drugs were given to the animal. One hour later, sodium heparin (100 U/kg) was administered intra-venously. The animal was sacrificed by acute exangu-ination. The aorta was opened longitudinally. The position of the thrombi on the aortic wall was macro-scopically observed and the weight of the thrombi attached to the catheters were measured. A piece of the aorta at each level was excised for light and scanning electron microscopic observations.

Mural thrombi of various lengths still remained on the aortic wall of every dog after the removal of the catheters. Microscopic observation revealed that the mural thrombus was formed on the aortic wall, where the endothelial cells had peeled off and the internal elastic membrane was partially destro-yed. SEM observation also showed that fibrin net-work on the aortic wall where the endotherial cells were peeled off.

Microscopic observation of aortic wall also re-vealed intimal tears, inner elastic membrane injury and bleeding in the elastic membrane. This damage could worsen leading to dissection of the aorta, thrombosis of the abdominal organs. The injury is considered due to mechanical irriation by the catheter.

There are many reports on the complications ac-companying catheterization but, to our knowledge, very few about the damage of the aortic wall.

From this study we conclude that the essential characteristic of the angiographic catheter should be emphasized such as, excellent antithrombogenicity and pliability.