Safety and Effectiveness of Mechanical Thrombectomy Using the Anaconda ANA5 Device

The objective of this study is to assess the safety and effectiveness of mechanical thrombectomy using the ANA funnel catheter to treat people with acute ischemic stroke within 24 hours of symptom onset. The device facilitates the placement of other devices such as stent retrievers and intravascular catheters during the procedure.

The objective of this prospective randomized study is to assess the primary safety and effectiveness of mechanical thrombectomy (MT) using the ANA funnel catheter in its intended use as a device to facilitate the insertion and deployment of other devices (i.e., stent retrievers and intravascular catheters) and to allow flow restriction during MT procedures performed in subjects experiencing acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO) of the internal carotid artery (ICA) and treated within 24 hours of symptom onset.

Acute reperfusion success after one pass (First Pass Effect, FPE) with ANA will be compared to an active control using the same stent retrievers delivered by an approved guide catheter with or without an intermediate catheter per conventional techniques. The study is designed to demonstrate that the use of ANA does not adversely impact the safety and effectiveness of a conventional stent retriever MT procedure.

Similar to other ancillary devices used in MT, the ANA device is designed to facilitate the delivery of stent retrievers and other catheters during these procedures. Its design aims to enhance procedural success and efficiency of stent retriever-based MT procedures by facilitating flow arrest during clot retrieval. This approach has been shown to improve rates of revascularization and good clinical outcome after three months. Numerous studies have established the value of flow arrest during MT, yet it is only used in a minority of procedures most likely due to concerns related to navigability, complexity and safety of the currently available devices.

Use of the ANA to facilitate MT with a stent retriever may provide a simplified approach to flow restriction, and may achieve similar acute reperfusion outcomes to commonly used approaches that combine direct aspiration with an intermediate catheter to actuate clot retrieval with a stent retriever (control). The study will report acute reperfusion success after a single thrombectomy pass with three of the most commonly employed stent retrievers, namely Solitaire, Trevo and pRESET. Procedural safety will be assessed by comparing the rate of procedure related sICH within 24 hours of the intervention between study arms.

Eligibility Criteria:
Key Inclusion Criteria:

1. A new focal disabling neurologic deficit consistent with acute cerebral ischemia.
2. Baseline National Institutes of Health Stroke Scale (NIHSS) obtained prior to procedure ≥ 8 points and ≤ 25 points.
3. Pre-ictal modified Rankin Score (mRS) score of 0,1 or 2.
4. Treatable within 24 hours of symptom onset, defined as point in time when the subject was last observed to be asymptomatic; treatment start is defined by arterial puncture time.
5. If indicated, thrombolytic therapy shall be initiated per the institution's usual care and the most recent version of the AHA/ASA Guidelines. Subjects eligible for IV thrombolysis should receive it without delay.
6. Occlusion (eTICI ≤ 1 flow) of the terminal carotid artery, middle cerebral artery M1 segment or, dominant or proximal M2 segment, indicated for mechanical thrombectomy, confirmed with conventional angiography or CTA/MRA.

Key Exclusion Criteria:

1. Subject was diagnosed with a stroke in the past year.
2. Clinical symptoms suggestive of bilateral stroke or stroke in multiple territories.
3. Severe, sustained uncontrolled hypertension refractory to treatment (systolic blood pressure \>185 mmHg or diastolic blood pressure \>110 mmHg).
4. Known pregnancy and/or lactating female.
5. CT or MRI evidence of hemorrhage (the presence of microbleeds is allowed).
6. Significant mass effect with midline shift.
7. Evidence of intracranial tumor (except small meningioma).
8. History of preexisting stent proximal to or at the occlusion site that may preclude safe deployment or recovery of the stent retriever.
9. Vessel tortuosity too difficult to allow endovascular access of the intracranial ICA per investigator judgement. Indicators of vessel tortuosity include but are not limited to the presence of carotid loops and type 3 aortic arches.
10. Evidence of tandem lesions, including complete occlusion, high grade stenosis or arterial dissection in the extracranial or internal carotid artery (ICA), requiring treatment or preventing access to thrombus.
11. Subjects with known or suspected underlying intracranial atherosclerotic lesions responsible for the target occlusion.
12. Subjects with occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation).
13. Anatomical or physiological restrictions (e.g., severe stenosis, vasospasm, high tortuosity, etc.) detected via angiogram likely to result in an inability to position the guide catheter or to deploy the ANA or intermediate catheter in the targeted ICA segment with acceptable vessel diameter as defined in the Instructions for Use.