Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy
Condition: Stroke
MeSH terms: Stroke
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to compare the effectiveness of treating acute ischemic stroke
      with mechanical embolectomy using the Merci Retriever or the Penumbra System within 8 hours
      of symptom onset to standard medical treatment, and to identify people who might benefit from
      mechanical embolectomy by the appearance of stroke on multimodal computerized tomography (CT)
      or magnetic resonance (MR) imaging.
    

Detailed description: 
      Stroke most commonly occurs when there is a blockage of blood flow to one of the arteries in
      the brain. The blockage is often caused by a clot. There is currently only one FDA-approved
      stroke treatment. However, only 2 percent of ischemic stroke patients receive this treatment
      because it must be given within 4.5 hours of the stroke onset. There is an overwhelming need
      for new treatments that extend the time window to treatment since most individuals with
      stroke arrive at the hospital after the 4.5-hour time window.

      Two of the most promising new devices are the Merci Retriever, a tiny corkscrew device, and
      the Penumbra System, an aspiration device. Both are designed to remove clots from arteries
      and thereby restore blood flow to the brain.

      The primary purpose of this study is to compare the effectiveness of treatment with the Merci
      Retriever or Penumbra System within 8 hours of symptom onset to standard medical treatment,
      and to identify people who might benefit from the devices by the appearance of the stroke on
      multimodal computerized tomography (CT) or magnetic resonance imaging (MRI). Previous testing
      has determined that the use of the Merci Retriever is successful in opening up blocked blood
      vessels in approximately ½ of the individuals in whom it is used, and the Penumbra System is
      successful in opening up blocked blood vessels in approximately 80% of the individuals in
      whom it is used.

      A total of 120 participants from approximately 30 different medical centers will be enrolled
      into this study. Participants will be randomized to either receive treatment by mechanical
      embolectomy with the Merci Retriever or Penumbra System and standard medical care or
      treatment with standard medical care alone. Standard care for stroke patients may include
      intravenous fluid, careful regulation of blood pressure, blood-thinning medicine (such as
      heparin or warfarin), anti-platelet medicine (such as aspirin or clopidogrel), and
      rehabilitation therapies.

      Participants undergoing the Merci Retriever or Penumbra System procedure will have a cerebral
      arteriogram with pictures taken with dye prior to the procedure to determine the location of
      the blockage, and following the procedure to determine if blood supply has been restored. The
      total mechanical embolectomy procedure with either device will take approximately 1 to 2
      hours. Participants will have brief neurological exams several times during this time to
      monitor changes in their neurological condition.

      Participants will have follow-up visits, including neurological exams, at 30 days and at 90
      days.

      This study is part of the Specialized Program of Translational Research in Acute Stroke
      (SPOTRIAS), which allows researchers to enhance and initiate translational research that
      ultimately will benefit stroke patients by treating more patients in less than 2 hours, and
      finding ways to treat additional patients later.
    

Intervention name(s): Merci Retriever and Penumbra System
Intervention type(s): Device
Intervention description(s): The MERCI (Mechanical Embolus Removal in Cerebral Ischemia) Retriever consists of a flexible, nickel titanium (nitinol) wire with a helical-shaped distal tip. The helical distal tip is covered with a platinum radiopaque coil, which facilitates fluoroscopic visualization. The body of the MERCI Retriever is covered with a hydrophilic coating that helps facilitate device placement. The MERCI Retriever is available in 6 configurations (Merci Retrievers X6, L5, L4, L6, V series, DAC).
The Penumbra System uses a reperfusion catheter in parallel with a separator component and an aspiration source to achieve separation of the thrombus and subsequent aspiration of the occlusion from the vessel. The system is available in different sizes according to the target vessels (041 Reperfusion Catheter/Separator pair for use in vessels larger than 3mm, notably the ICA and M1; 032 Reperfusion Catheter/Separator pair for use in vessels 2mm - 3mm, notably the M2).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: stroke; ischemic stroke; blood clot; Merci Retriever; Penumbra System; embolectomy; magnetic resonance imaging; MRI; CT; SPOTRIAS