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


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Gobin
Y Pierre
YP
Division of Interventional Neuroradiology, Weill Cornell Medical College, New York Presbyterian Hospital, New York, NY 10021, USA. yvg2001@med.cornell.edu
Starkman
Sidney
S
Duckwiler
Gary R
GR
Grobelny
Thomas
T
Kidwell
Chelsea S
CS
Jahan
Reza
R
Pile-Spellman
John
J
Segal
Alan
A
Vinuela
Fernando
F
Saver
Jeffrey L
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000601:surgery*; D017128:Embolectomy / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged