Endovascular Therapy in Acute Ischaemic Stroke Due to Large Vessel Occlusion

Aim of Study: To develop a standardized patient selection criteria and imaging protocol for endovascular therapy in acute ischaemic stroke (AIS) To create a local efficacy and safety database for intra-arterial mechanical thrombectomy devices use To establish predictors for poor functional outcome despite successful recanalization Study Design: Prospective Subject and Site: 100 acute ischaemic stroke patients with large vessel occlusion At Queen Mary and Ruttonjee Hospital, Hong Kong Duration of participation: 2 years Entry Criteria: Subject must meet all inclusion criteria and none of the exclusion criteria Consent: Both English and Chinese versions of Informed consent are available and will be obtained from patient or his/her next of kin

Our study aim to set a standard patient selection and imaging protocol based on previous positive trials for endovascular therapy in AIS patients. Local efficacy and safety data of the FDA mechanical devices mainly Penumbra Aspiration System and Solitaire Flow Restoration device will be collected to create a local database for future service development. Clinical predictors for poor clinical outcomes despite successful recanalization will be looked for. Intra-arterial treatment consisted of arterial catheterization with a micro-catheter and micro-guide wire to the level of occlusion. Mechanical treatment could involve thrombus aspiration technique or use of a retrievable stent. The method of intra-arterial treatment will leave to the discretion of the involved interventionist. Only devices that have received U.S. Food and Drug Administration (FDA) or Conformite Europeenne (CE) approval will be used in the trial. One or more members of each intervention team have to have completed at least five full procedures with a particular type of device. Outcome and Safety Measures: The primary outcome is 90 days modified Rankin scale. The modified Rankin scale is a 7-point scale ranging from 0 (no symptoms) to 6 (death). A score of 2 or less indicates functional independence. Secondary outcomes include: NIHSS score at 24 hours and at 7 day or discharge if earlier Activities of daily living measured using Barthel index and NIHSS at 90 days Percentage of successful recanalization, defined as modified Thrombolysis in Cerebral Infarction (mTICI) of 2b (more that 50% of distal branches visible) or 3 (all distal branches visible) assessed at the end of procedure Efficacy of work flow with time measure on onset to CT, CT to groin puncture, puncture to reperfusion and number of pass of device before successful recanalization Final infarct volume measured by plain CT brain at 3 days after procedure Death

Patients will be randomized to use either the Aspiration System or one of the stent-retreivers (Trevo / Solitaire) first. Other devices would be used if the first device failed to open the occluded vessel satisfactorily, depending on clinical situation and the involved interventionists' preferences.

Use aspiration system (mainly Penumbra) first, other devices would be used if the first device failed to open the occluded vessel satisfactorily, depending on clinical situation and the involved interventionists' preferences.

Use one of the stent retrievers (Trevo / Solitaire) first, other devices would be used if the first device failed to open the occluded vessel satisfactorily, depending on clinical situation and the involved interventionists' preferences.

The primary outcome is 90 days modified Rankin scale. The modified Rankin scale is a 7-point scale ranging from 0 (no symptoms) to 6 (death). A score of 2 or less indicates functional independence.

NIHSS score at 24 hours and at 7 day or discharge if earlier. NIHSS score describe the clinical severity of stroke symptoms, and is scored from 0 (no symptoms) to 42 (most severe deficits). The total NIHSS score before, at 24 hours after intervention and subsequent follow up will be assessed.

Activities of daily living measured using modified Barthel index (mBI). modified Barthel Index is a measurement of independence of daily living, the score ranges from 0 to 100, with higher score correlating to better outcome.

Percentage of successful recanalization, defined as modified Thrombolysis in Cerebral Infarction (mTICI) of 2b (more that 50% of distal branches visible) or 3 (all distal branches visible) assessed at the end of procedure

Inclusion Criteria: Onset: ≤ 4.5 hours from symptoms onset Age < 80 Premorbid modified Rankin Score (mRS) ≤ 2 NIHSS 8 - 29 Clear and definite symptoms and signs suggesting stroke with hemiparesis as one of the presenting symptoms Plain CT brain showed no evidence of intracerebral haemorrhage and ASPECTS ≥ 7 Multiphasic CT angiogram confirmed proximal vessel occlusion at internal carotid artery (ICA), carotid T junction, proximal middle cerebral artery (M1 segment to proximal M2 with loss of all M2 branches), proximal anterior cerebral artery (segment A1) or basilar artery Exclusion Criteria: Interventionist or angio-laboratory not available Neurological signs rapidly resolving NIHSS>29 Evidence of cerebral haemorrhage or subarachnoid haemorrhage on CT brain ASPECTS<7 Excessive tortuosity of the vessel precluding device delivery Known chronic renal failure with creatinine level >250umol/L Known haemorrhagic diathesis Known coagulation factor deficiency Difficult blood pressure control with persistent systolic blood pressure >185mg or diastolic blood pressure >110mg despite aggressive blood pressure lowering therapy On anticoagulant and INR≥3 On heparin in previous 48 hour and APTT>2x of normal Platelet counts <30 Blood glucose <2.7mmol/L Known severe allergies to contrast medium Seizure as presenting symptoms with post-ictal hemiparesis Life expectancy < 3months Pregnant