Evaluation of the CONDA Stent Retriever in Acute Ischemic Stroke

ARTEMIS is a pilot prospective, multi-center, single-arm, open-label, interventional study. Standard of care clinical and imaging stroke assessments will determine subject eligibility. The objective of this study is to assess the performance, safety and preliminary efficacy of mechanical thrombectomy (MT) using the CONDA device in its intended use as a stent retriever to enable the entrapment and removal of clotted blood in the neurovasculature in subjects experiencing acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO) and treated within 24 hours of symptom onset. The ARTEMIS study is designed to demonstrate that the use of CONDA does not adversely impact the safety and effectiveness of a conventional stent retriever MT procedures.

Inclusion criteria

• Age 18 to 85 years.
• Informed consent was obtained from subject or acceptable subject surrogate (e.g., next of kin, or legal representative).
• New focal disabling neurologic deficit consistent with acute cerebral ischemia.
• Baseline NIHSS obtained prior to procedure ≥ 6 points and ≤ 25 points.
• Pre-ictal mRS score of 0, 1 or 2.
• Treatable within 24 hours of stroke symptom onset.
• If indicated, thrombolytic therapy shall be initiated following recommendations established by the AHA/ASA and/or ESO Guidelines. Subjects eligible for IV thrombolysis should receive it without delay.
• Extended Thrombolysis in Cerebral Infarction (eTICI) Score 0 - 1, confirmed by angiography or CTA/MRA of the:

• Intracranial internal carotid artery (ICA)
• Middle cerebral artery - M1 segment
• Middle cerebral artery - M2 proximal or dominant segments
• Imaging criteria:

• Alberta Stroke Program Early CT Score (ASPECTS) 6 to 10 on baseline CT or DWI-MRI.
• If automated assessment, core volume of ≤50 cc on CTP/ DWI-MRI.

Exclusion criteria

The following exclusion criteria will be assessed pre-operatively:

• Rapid neurological improvement prior to enrollment suggesting resolution of stroke.
• Subject was diagnosed with a stroke in the last 6 months.
• Clinical symptoms suggestive of bilateral stroke or stroke in multiple territories.
• Clinical presentation suggests subarachnoid hemorrhage.
• Known hemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with antivitamin K, with INR >3.0.
• Known baseline glucose of <50 mg/dL or >400 mg/dL.
• Severe, sustained uncontrolled hypertension refractory to treatment (systolic blood pressure >185 mmHg or diastolic blood pressure >110 mmHg).
• Serious, advanced, or terminal disease with anticipated life expectancy of less than 1 year.
• Known history of severe sensitivity (more than rash) to contrast medium.
• Known history of severe sensitivity to nickel, titanium metals or their alloys.
• Known renal insufficiency with creatinine ≥3 mg/dL or glomerular filtration rate (GFR) <30 mL/min.
• Subject requires hemodialysis or peritoneal dialysis.
• Subject is a current user or has a recent history of cocaine and/or heroin use.
• Known pregnancy and/or lactating female.
• Subject is participating in a concurrent study involving an investigational drug or device that would impact the primary endpoint of this study.
• Subject is unlikely to be available for a 90-day follow-up (e.g., no fixed home address, visitor from overseas, etc.)
• CT or MRI evidence of hemorrhage (the presence of microbleeds is allowed).
• CT or MRI evidence of significant mass effect with midline shift.
• CT or MRI evidence of intracranial tumor (except asymptomatic meningioma of ≤ 2cm in diameter).
• CT or MR evidence of cerebral vasculitis.
• Suspicion of aortic dissection, presumed septic embolus, or bacterial endocarditis.
• History of preexisting stent proximal to or at the occlusion site that may preclude safe deployment or recovery of the stent retriever.

The following exclusion criteria will be assessed intra-operatively:

• eTICI score improvement to greater than eTICI 1 after initial screening and prior to intervention.
• Initially treated with a different thrombectomy device during the current study procedure.
• Vessel tortuosity too difficult to allow endovascular access of the intracranial internal carotid artery (ICA) per investigator judgement. Indicators of vessel tortuosity include but are not limited to the presence of carotid loops and type 3 aortic arches.
• Evidence of tandem lesions, including complete occlusion, high-grade stenosis or arterial dissection in the extracranial or intracranial internal carotid artery (ICA), requiring treatment or preventing access to thrombus.
• Underlying intracranial atherosclerotic disease (ICAD) lesions responsible for the target occlusion.
• Occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation).
• Inability to gain arterial access.