Multi MERCI (Mechanical Embolus Removal in Cerebral Ischemia [MERCI™])

A Multinational Controlled Registry to Evaluate the Concentric Merci Retriever System (Mechanical Embolus Removal in Cerebral Ischemia [MERCI™])

The primary objectives of the Multi MERCI trial were:

• to evaluate the addition of the Merci L5 Retriever
• additionally permit use of the Merci Retrieval System in the setting of persistent clot following IV t-PA treatment (use in the 0-8 hour window for patients ineligible for IV t-PA was also permitted)

Per the Multi MERCI protocol, up to 230 patients could be treated at up to 30 centers.

The intended trial indication for the Merci L5 Retriever was to restore blood flow in the neurovasculature by removing thrombus in patients experiencing ischemic stroke. Patients that were contraindicated or failed treatment with intravenous t-PA were allowed to be enrolled under the Multi MERCI protocol.

Per the Multi MERCI protocol, following inclusion of the Merci L5 Retriever the operating physician was required to initiate treatment with the Merci L5 Retriever. At the physician's discretion, subsequent passes could be made with the Merci L5 Retriever, Merci X6 Retriever and/or Merci X5 Retriever.

Adverse events were adjudicated by an independent Data Safety and Monitoring Board (Capital DSMB).

Inclusion Criteria:

• Angiographically confirmed large vessel ischemic stroke (occlusion may include the following: internal carotid artery (ICA), M1/M2, vertebral, or basilar arteries)
• Intervention is able to be performed within 8 hours of symptom onset
• Patients > 18 years of age
• NIHSS score 8+
• Failed IV t-PA treatment or contraindicated for IV t-PA

Exclusion Criteria:

• International Normalized Ratio (INR) > 3.0
• Platelet count < 30,000
• Heparin use in previous 24 hours with PTT > 2X normal
• Baseline bloog glucose < 50 mg/dL
• Baseline computed tomography (CT) showing mass effect with midline shift
• Severe sustained hypertension (SBP > 185 or DBP > 110) that cannot be controlled with medication
• Patient is pregnant, has anticipated life expectancy < 3 months, or has severe allergy to contrast medium
• Arterial stenosis > 50% proximal to embolus
• Excessive arterial tortuosity that precludes the study device from reaching the target area