Managing Intracoronary Thrombus During PCI

Abstract

Occlusive or nonocclusive thrombosis triggered by a disrupted or eroded atherosclerotic plaque is the anatomic substrate of most acute coronary syndromes including ST-segment elevation myocardial infarctions (AMI). For this pathological substrate, macro- and microembolization during percutaneous coronary intervention (PCI) in the setting of AMI is frequent and may result in obstruction of the microvessel network, and decreased efficacy of reperfusion and myocardial salvage. Thrombus may complicate other complex anatomic conditions associated with an altered flow such as ectatic or aneurysmatic coronary arteries, degenerated venous grafts, or coronary stents. Removal of thrombus before any other intervention may dramatically decrease the risk of no-flow, and has the potential for improvement in survival. Many types of thrombectomy removal or protection devices are currently available, from low technology catheters based on manual thrombus aspiration, including proximal or distal antiembolic protection devices, to high technology devices using mechanical energy allowing fragmentation and removal of thrombus. Studies on thrombectomy before stenting have produced conflicting results and there is no consensus as to their routine use in lesions containing thrombus. Other procedural approaches include specific covered and self-expandable stents for thrombus jailing, or deferred stenting after prolonged infusion of antithrombotic drugs.