- Acute ischemic stroke is a medical emergency in which each minute is counted
- TIME-IS BRAIN
- 2 million neurons are lost each minute after ischemic injury
- The therapeutic approach to acute stroke treatment has been deeply transformed over two decades
- Nihilism on stroke treatment is long gone, it has been replaced by the excitement of proven treatment options
- IV thrombolysis – IVT
- Mechanical thrombectomy – EVT
- These two options can reverse ischemia and bring back functions to the patients.
- Without these options these patients will otherwise be destined to death or severe disability
- The three main principles of acute stroke are
- Achieve timely recanalization of the occluded artery and reperfusion of the ischemic tissue
- Optimize collateral flow
- Avoid secondary brain injury
- Three zones of injury may occur the following LVO
- Ischemic core zone (Tissue irreversibly injured)
- Ischemic penumbra (Ischemic but still viable cerebral tissue
- Benign oligemia zone (area with milder reduction in tissue
Perfusion that does not place the tissue at risk)
- Ischemic penumbra,
- Ischemic penumbra is an area of brain tissue that is viable but is critically hypoperfused and will progress to infarct in the absence of timely reperfusion.
- Collateral circulation
- Primary collaterals refers to circle ofwillis —ACOM and PCOM.
- Secondary collaterals refers to Ophthalmic artery and Leptomeningeal arteries
- Tertiary collaterals refers to newly developed vessels through angiogenesis – 1. But overtime thrombi tend to become more fibrin rich 2.Red blood cell rich thrombi are more permeable to blood flow and respond to thrombolytics
- DSA is a gold standard to evaluate the collateral anatomy.
- Both IVT and EVT are safe and effective for the right candidate
- Patient selection is crucial to optimize outcomes
- Attitude of the clinician should be the treatment should be given unless a solid contraindications exits
- Expansion of therapeutic window for emergency reperfusion adds merit to these procedures
- Therapeutic window for IV thrombolysis was extended from 3 to 4 1/2 hours and is has been extended now upto 6 hours.
- T h e ra p e u t i c wi ndow to mechanical thrombectomy
- Upto is for 24 hours
- Upto 6 hours, we may try IVT (IV)
(Thrombolysis ) + EVT (Endovascular treatment)
- After 6 hours are upto 24 hours mechanical thrombectomy can be done if collaterals are good and core volume is small and if it is LVO
- Nature of Thrombus
- Thrombi within the intracranial tree are either formed in situ or reach there as emboli. A freshly formed thrombus is red blood cell rich.
- Hemodynamicaugmentation & BID Targets
- Collateral flow can be protected by avoiding BP drops and supported by the administration of IV fluids.
- If BP drop occurs keep the patient in a laying-flat position for 24 hours after admission (Head-post trial) — Head position stroke trial
- Aspiration should be taken care of
- Vasopressors may be beneficial in selected cases — such as patient with cervical ICA/ LV occlusion.
- Keep the BP around 180/100 for 24 hours.
