The Role of Coronary Arteriography in Demonstration of Mural Thrombosis after Angioplasty (10)

Yet 33 percent of AT— thrombi were of the same size as AT + values, ranging from 27 percent to 75 percent of the arterial lumen area. In these cases, negativity of the arteriogram must be explained by factors other than small thrombus size or the lumen-stretching effect of arterial distention.
Our data indicate that the composition of thrombus may influence its arteriographic demonstration, fibrin-rich thrombi being more likely to be detected than fibrin-poor ones. However, the information given by this variable is not independent of size alone.
Slowed blood flow could enhance contrast material retention and favor demonstration of thrombi, as suggested by the high sensitivity of arteriography in detecting occlusive thrombosis in acute myocardial infarction.’ In 12 of 17 AT + dogs, unlike AT— dogs, arterial flow was slowed, most often in association with large intracoronary thrombi. Although the effects of slowed flow upon thrombus demonstration cannot be separated from those of size alone, other factors contributing to decreased flow should also be considered, such as superimposed vasospasm and even arteriolar constriction. Finally, the complex geometric configuration of mural thrombi must be mentioned. For example, in many cases, the thrombus is attached to the wall by a narrow peduncle; the arteriographic contrast that fills the space between the thrombus and the wall may preclude demonstration of a rather bulky intraluminal structure. Also, a flat thrombus attached to the dilated portion of an artery could be quite large relative to the lumen area and yet induce little absolute decrease in lumen area, thus escaping arteriographic detection.