[Acute coronary occlusion during transluminal angioplasty: role of coronary thrombosis]

We here report on 2 patients treated by transluminal coronary angioplasty, who presented baseline angiographic aspects of an intracoronary thrombus upon vessel stenosis. In both cases mechanical dilatation was successful in increasing vessel diameter, but was complicated by activation of the thrombotic process with clot proliferation--as shown by multiple coarse filling defects irregularly stained by contrast material--and vessel occlusion. The intracoronary injection of streptokinase achieved partial slowing of the thrombotic process, but did not succeed in inhibiting it completely or in restoring vessel patency. As clinical conditions were stable, the patients were not sent to emergency surgery, but were treated conservatively with anticoagulants and platelet inhibitors: in only one patient the procedure was followed by moderate myocardial enzyme release. In both cases the coronary artery was patent at short term angiographic control. These 2 cases confirm that in the outset of transluminal angioplasty an acute coronary occlusion can be managed conservatively by thrombolytic treatment when thrombus formation can be clearly identified the cause of vessel occlusion: the activation of spontaneous lytic systems can completely restore vessel patency. If coronary occlusion was of short duration or collateral supply was adequate, myocardial infarction may not occur and emergency coronary surgery will not be necessary.