Protocol Number: 04-N-0264

Title:

MR Rescue: MR and Recanalization of Stroke Clots using Embolectomy

Number:

04-N-0264

Summary:

This study will use magnetic resonance imaging (MRI) to compare embolectomy (surgical removal of a clot) using an experimental device called the Merci Retriever with standard treatment in acute stroke patients and to identify people who might benefit from the device. The Merci Retriever is a small metal wire with a loop at the end that removes clots from arteries, restoring blood flow to the brain, and thus possibly causing symptoms to improve or preventing them from getting worse. MRI is a test that uses a strong magnetic field and radio waves to obtain images of body organs and tissues.

Patients between 18 and 85 years of age who have had a stroke caused by blockage in one of the major brain arteries within 8 hours of the proposed experimental treatment may be eligible for this study. Patients whose stroke results from bleeding may not participate. Candidates are evaluated with a neurological examination, MRI and blood tests.

Participants are randomly assigned to receive treatment with the Merci Retriever plus standard medical care or standard medical care alone. Patients selected for the Merci Retriever undergo an arteriogram to show the blockage in the arteries that supply blood to the brain. For this test, a catheter (plastic tube) is inserted into a blood vessel in the groin that leads to the brain. A smaller tube is then passed directly into the blocked brain artery. A contrast material is injected into the small tube to locate the blockage. Then the Merci Retriever is passed through the tube in the groin and up through the artery to the clot. The device is then pulled back with the clot attached and pulled out of the body. Patients then undergo a second arteriogram to determine if the blood supply in the blocked artery has been restored. During the arteriograms and the embolectomy, patients are given several brief neurological examinations and their blood pressure and heart rhythm are monitored.

All patients receive standard medical care for treatment of acute stroke. Seven days after the stroke, they undergo a repeat MRI scan and brief neurological examination. At 30 days, they have a telephone follow-up, and at 90 days they return to the clinic for a follow-up neurological examination.

Sponsoring Institute:

National Institute of Neurological Disorders and Stroke (NINDS)

Recruitment Detail

Type: Participants currently recruited/enrolled

Gender: Male & Female

Referral Letter Required: Yes

Population Exclusion(s): Children

Eligibility Criteria:

INCLUSION CRITERIA:

New focal disabling neurologic deficit consistent with acute cerebral ischemia (NIHSS greater than or equal to 6).

Age greater than or equal to 18 and less than or equal to 85.

Clot Retrieval Procedure can be initiated within 8 hours of symptom onset.

Large vessel proximal anterior circulation occlusion on MR angiography (internal carotid, M1 or M2 MCA).

Signed informed consent obtained from the patient or patient's legally authorized representative.

Pretreatment MRI performed according to MR RESCUE protocol.

Premorbid modified Rankin score of 0-1.

Allowed but not required: patient treated with IV TPA with persistent target occlusion on post-treatment MR RESCUE protocol MRI performed at the completion of drug infusion (Note: Rapidly improving neurological signs prior to randomization is an exclusion).

EXCLUSION CRITERIA:

NIHSS greater than or equal to 30.

Contraindication to MRI (pacemaker, etc).

Acute intracranial hemorrhage.

Coma.

Rapidly improving neurological signs prior to randomization.

Pre-existing medical, neurological or psychiatric disease that would confound the neurological, functional, or imaging evaluations.

Pregnancy.

Renal Failure (serum Creatinine greater than 2.0 or Glomerular Filtration Rate [GFR] , 30) unless patient is dialysis dependent.

Known allergy to iodine previously refractory to pretreatment medications.

Current participation in another experimental treatment protocol.

Contrast-Enhanced Neck MRA suggests proximal ICA occlusion, proximal carotid stenosis greater than 67%, or dissection.

INR greater than 3.0.

PTT greater than 3 x Normal.

Diffusion-perfusion data cannot be processed my MR RESCUE computer.

Special Instructions:

Currently Not Provided

Keywords:

Ischemia

Brain

Penumbra

Clinical Trial

Endovascular

Recruitment Keyword(s):

None

Condition(s):

Cerebrovascular Accident

Investigational Drug(s):

None

Investigational Device(s):

Concentric Retriever System

Intervention(s):

Device: Concentric Retriever System

Supporting Site:

National Institute of Neurological Disorders and Stroke

Contact(s):

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citation(s):

Fisher M. Characterizing the target of acute stroke therapy. Stroke. 1997 Apr;28(4):866-72.

Furlan M, Marchal G, Viader F, Derlon JM, Baron JC. Spontaneous neurological recovery after stroke and the fate of the ischemic penumbra. Ann Neurol. 1996 Aug;40(2):216-26.

Barber PA, Darby DG, Desmond PM, Yang Q, Gerraty RP, Jolley D, Donnan GA, Tress BM, Davis SM. Abstract Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI. Neurology. 1998 Aug;51(2):418-26.

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