Mechanical Thrombectomy for Acute Ischemic Stroke

Abstract

Background and Purpose-Endovascular mechanical thrombectomy may be used during acute ischemic stroke due to large vessel intracranial occlusion. First-generation MERCI devices achieved recanalization rates of 48% and, when coupled with intraarterial thrombolytic drugs, recanalization rates of 60% have been reported. Enhancements in embolectomy device design may improve recanalization rates. Methods-Multi MERCI was an international, multicenter, prospective, single-arm trial of thrombectomy in patients with large vessel stroke treated within 8 hours of symptom onset. Patients with persistent large vessel occlusion after IV tissue plasminogen activator treatment were included. Once the newer generation (L5 Retriever) device became available, investigators were instructed to use the L5 Retriever to open vessels and could subsequently use older generation devices and/or intraarterial tissue plasminogen activator. Primary outcome was recanalization of the target vessel. Results-One hundred sixty-four patients received thrombectomy and 131 were initially treated with the L5 Retriever.Mean ageϮSD was 68Ϯ16 years, and baseline median (interquartile range) National Institutes of Health Stroke Scale score was 19 (15 to 23). Treatment with the L5 Retriever resulted in successful recanalization in 75 of 131 (57.3%) treatable vessels and in 91 of 131 (69.5%) after adjunctive therapy (intraarterial tissue plasminogen activator, mechanical). Overall, favorable clinical outcomes (modified Rankin Scale 0 to 2) occurred in 36% and mortality was 34%; both outcomes were significantly related to vascular recanalization. Symptomatic intracerebral hemorrhage occurred in 16 patients (9.8%); 4 (2.4%) of these were parenchymal hematoma type II. Clinically significant procedural complications occurred in 9 (5.5%) patients. Conclusions-Higher rates of recanalization were associated with a newer generation thrombectomy device compared with first-generation devices, but these differences did not achieve statistical significance. Mortality trended lower and the proportion of good clinical outcomes trended higher, consistent with better recanalization. (Stroke. 2008;39:1205-1212.)

Acute stroke intervention by interventional cardiologists

“…However, intravenous thrombolysis is less effective in large intracerebral vessel occlusion (distal internal carotid artery or proximal MCA), where mechanical thrombectomy with or without intra-arterial thrombolysis achieves higher patency rates [10,14,28,29]. Consistent with outcomes reported for acute myocardial infarction, early and successful recanalization of the stroke-related artery appears to correlate with improved clinical outcomes [13,[30][31][32].…”

“…The mechanical embolus removal in cerebral ischemia (MERCI) trial led to the FDA approval of the Merci Retrieval System (Concentric Medical, Mountain View, CA) for mechanical thrombectomy of large cerebral vessels [13]. Since its initial approval, this device has been redesigned, resulting in improved recanalization rates, especially when used in conjunction with other modalities [14]. The penumbra device (Penumbra, San Leandro, CA) is an FDA-approved thrombectomy catheter, which demonstrated promising results in a recently reported efficacy trial [15].…”

Intra-arterial Therapy for Acute Ischemic Stroke

“…The follow-up study, the Multi MERCI trial was an international, multicenter, single-arm trial with plans to obtain further safety data of the first generation Merci Retrievers (X5 and X6), explore the safety and technical efficacy of the devices in patients who "fail" IV thrombolysis, and collect safety and efficacy data on the secondgeneration Retriever (L5) [55,72]. A total of 177 patients were enrolled in the Multi MERCI trial, but the device was deployed in only 164 patients, with a mean age of 68.1± 16.0 years.…”

Mechanical Thrombectomy in Basilar Artery Thrombosis: Technical Advances and Safety in a 10-Year Experience

“…During the last decade, several transarterial techniques for mechanical thrombectomy (MT), including suction, have been introduced in acute stroke therapy [7][8][9][10][11]. MT seems to be a more effective and probably less hazardous endovascular technique than intra-arterial fibrinolysis to achieve rapid and complete restoration of the blood flow, which is crucial for a favourable prognosis in patients with BAO [2][3][4]6].…”

“…MT seems to be a more effective and probably less hazardous endovascular technique than intra-arterial fibrinolysis to achieve rapid and complete restoration of the blood flow, which is crucial for a favourable prognosis in patients with BAO [2][3][4]6]. The recent MERCI [9,10] and Penumbra [8] studies presented promising recanalization rates in the anterior and posterior circulation. Similar results have been reported in small studies and case reports considering the vertebrobasilar circulation alone [7,11].…”