MERCI 1: a phase 1 study of Mechanical Embolus Removal in Cerebral Ischemia

• Published in: Stroke (1970) Vol. 35; no. 12; pp. 2848 - 2854
• Main Authors: Gobin, Y Pierre, Starkman, Sidney, Duckwiler, Gary R, Grobelny, Thomas, Kidwell, Chelsea S, Jahan, Reza, Pile-Spellman, John, Segal, Alan, Vinuela, Fernando, Saver, Jeffrey L
• Format: Journal Article
• Language: English
• Published: United States 01-12-2004
• Subjects: Adult; Aged; Aged, 80 and over; Brain Ischemia - surgery; Embolectomy - instrumentation; Female; Humans; Male; Middle Aged
• ISSN: 0039-2499; 1524-4628
• DOI: 10.1161/01.STR.0000147718.12954.60

To report the result of the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) 1 study, a phase 1 trial to evaluate the safety and efficacy of mechanical embolectomy in the cerebral vasculature.
MERCI 1 enrolled 30 patients in 7 US centers. Main inclusion criteria were: National Institutes of Health Stroke Scale score (NIHSS) > or =10; treatment performed within 8 hours from symptoms onset and contra-indication to intravenous thrombolysis; no large hypodensity on computed tomography; and occlusion of a major cerebral artery on the angiogram. Safety was defined by the absence of vascular injury or symptomatic intracranial hemorrhage. Efficacy was assessed by recanalization rate and clinical outcome at 1 month. Significant recovery was defined as 30-day modified Rankin of 0 to 2 in patients with baseline NIHSS 10 to 20 and 30-day modified Rankin of 0 to 3 in patients with baseline NIHSS >20. The procedures were performed with the Merci Retrieval System, a system specially designed for intracranial embolectomy.
Twenty-eight patients were treated. Median NIHSS was 22. Median time from onset to completion of treatment was 6 hours and 15 minutes. Successful recanalization with mechanical embolectomy only was achieved in 12 (43%) patients, and with additional intra-arterial tissue plasminogen activator in 18 (64%) patients. There was one procedure related technical complication, with no clinical consequence. Twelve asymptomatic and no symptomatic intracranial hemorrhages occurred. At 1 month, 9 of 8 revascularized patients and 0 of 10 nonrevascularized patients had achieved significant recovery.
This phase 1 study shows that cerebral embolectomy with the Merci Retriever was safe and that successful recanalization could benefit a significant number of patients, even when performed in an extended 8-hour time window.