The Evolution of Technology

The historical development of technologies for catheter-based reperfusion of the acutely ischemic human brain is brief but eventful (Table). The first clinical patients were treated with local microcatheter delivery of intra-arterial fibrinolytics in the mid-1990s. The first mechanical recanalization technique, primary intra-arterial balloon angioplasty, was described a few years later. Over the subsequent decade and a half, successive waves of innovative mechanical thrombectomy devices were introduced. The rapid proliferation of technology reflects the inherent dynamic of biomechanical device development, characterized by rapid engineering innovation focused on a well-circumscribed target, in contrast to the slower, more deliberate arc of drug development, which requires extensive testing of each new molecular entity for unexpected off-target effects on diverse organs.The heterogeneity of target vascular lesions in cerebrovascular disease mandates a diversity of mechanical treatment options for deployment by interventionalists. In many patients, the intracranial occlusion is an embolus that has arisen from the heart or a proximal aortocervical arterial source and landed in a relatively normal recipient artery. Such target thrombi respond well to retrieval and aspiration strategies. In other patients, the occlusive lesion is comprised of an in situ intracranial atherosclerotic plaque with supervening thrombosis. These target lesions will not respond well to retrieval devices, which catch on the plaque, or to aspiration devices, which are effective only for the thrombus component. However, they do respond well to angioplasty and stenting, which accomplish controlled cracking and dissection of the underlying atherosclerotic lesions.1 There is a notable race, ethnic variation in the composition of intracranial occlusions.2 Among whites, emboli from the heart or extracranial arterial sources are common; among Asians and blacks, in situ intracranial atherosclerosis with supervening thrombosis is more frequent. As a result, the most effective and commonly used mechanical treatment strategies vary regionally across the globe.The endovascular …