Post-Market Registry on Use of Merci Retrieval System. Primary data to be collected will include:

• Post-procedure revascularization success
• 90-day mRS 0-2
• 90-day mortality

The Merci Registry is a prospective multicenter registry with up to 3000 patients enrolled at a maximum of 100 sites.

The registry requires use (at least one pass in the intracranial vasculature) of any Merci Retriever device (X Series, L Series, V Series) in the setting of acute ischemic stroke due to large vessel intracranial occlusion.

Inclusion Criteria:

• Patient with ischemic stroke is treated with a Merci Retriever that is indicated for thrombus removal in ischemic stroke. "Treated" is defined as being when a Merci Retriever is deployed in the neurovasculature of a patient with an ischemic stroke
• Patient/patient's surrogate provides informed consent and is willing to comply with the protocol requirements and complete required clinical evaluations, or in the absence of informed consent, an IRB/EC approved waiver of consent and executed data use agreement are in place

Exclusion Criteria:

-There are no exclusion criteria for this protocol

All patients with ischemic stroke treated with a Merci Retriever either alone or in combination with adjunctive therapies such as lytics will be included in the Registry.