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Nihilism on stroke treatment is long gone, it has been replaced by the excitement of proven treatment options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 is an area of brain tissue that is viable but is critically hypoperfused and will progress to infarct in the absence of timely reperfusion.
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.