"Revolutionizing Stroke Care: Endovascular Therapy and Neuro Intervention in Acute Ischemic Stroke with Dr. Ganesh"
🌟 Greetings, everyone! Dr. Ganesh here, and today, we're exploring a groundbreaking topic that's transforming the landscape of stroke care: Endovascular Therapy and Neuro Intervention in Acute Ischemic Stroke (AIS). Whether you're a healthcare professional, a patient, or simply intrigued by medical advancements, this discussion is tailored for you.
2. Time is brain
Ischemic core zone, blood flow less than 10% to 25% of the normal cerebral
blood flow with consequent loss of oxygen and glucose results in rapid
depletion of energy stores, leading to necrosis of neurons and glial cells.
It is estimated that 1.9 million neurons are lost during each minute of ischemia
3. ENDOVASCULAR
THERAPY
Why Endovascular therapy
Narrow time window with IV tPA
Contraindications (recent surgery, coagulation abnormalities, and a history of ICH)
i.v tPA is less effective at opening LVO
Early recanalization after i.v tPA in only about one third of patients with an occlusion of the internal-
carotid-artery
4. Extended window
Role in scenarios of
Slow progressors
Wake up stroke
Unwitnessed stroke
LVO with minor deficits and then
worsen later
• Factors which predict response
in Extended time window
• Core clinical mismatch
• Core Penumbra mismatch
>1.8,Core<70ml
• DWI-FLAIR mismatch
5. Tissue window
Concept of “tissue window” v/s time window has proved useful for selecting patients for
mechanical thrombectomy up to 24 hours from symptom onset.
This concept made development and optimization of endovascular therapies for acute
ischemic stroke
Penumbra -Described as the area of brain tissue that is still viable but is critically hypo
perfused and will progress to infarct in the absence of timely reperfusion
6. Tissue window
The duration of the penumbra in humans varies substantially, depending on
factors such as
Degree of collateral blood flow supply,
Cerebral perfusion pressure,
Susceptibility of tissue to ischemia and ischemic preconditioning
Location of the vessel occlusion
Factors such as hyperglycemia, body temperature, and oxygen delivery
capacity
9. Mechanical Thrombectomy Eligibility–Vessel
Imaging
NIHSS score is the best of the LVO prediction instruments.
Threshold of ≥10 would provide the optimal balance between sensitivity
(73%) and specificity (74%).
Threshold of ≥6 would have 87% sensitivity and 52% specificity.
The sensitivity of CTA and MRA compared with the gold standard of catheter
angiography ranges from 87% to 100%, with CTA having greater accuracy
than MRA.
10. For patients who meet criteria for MT, noninvasive vessel imaging of the intracranial
arteries is recommended during the initial imaging evaluation
Risk of contrast-induced nephropathy secondary to CTA imaging is relatively low,
particularly in patients without a history of renal impairment
11. Perfusion imaging
For patients planned for
endovascular revascularization
presenting after 6 hours of
symptom onset
3 parameters:
A) Mean transit time.
B) Cerebral blood volume.
C) Cerebral blood flow.
13. Class- 1a
Class 2a- Last seen normal 16-24 hours from symptom onset (meeting criteria)
Class 2b- M2,M3 involvement, PCA territory, MRS >1, ASPECT <6, NIHSS <6
INDICATIONS-MT
14. Mechanical thrombectomy
Multiple randomized trials have shown thrombectomy benefit, up to 24 hours
after symptom onset.
MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, EXTEND-IA, THRACE, DAWN,
DEFUSE 3 Trials
Benefit was consistent across age groups
Patient selection criteria varies based on time
o Within 6 hours and 6-24 hours since last normal, advanced imaging with CT
perfusion or MRI/MR Perfusion is necessary to select patients
Stent retrievers are preferred devices
17. DAWN (DWI or CTP Assessment With Clinical Mismatch in
the Triage of Wake-Up and Late Presenting Strokes Undergoing
Neuro intervention) 6-24 HOURS
Trial included patients at a median of 12.5 hours from onset and showed the
largest effect in functional outcome ever described in any acute stroke treatment trial
(35.5% increase in functional independence)
DEFUSE 3 (Diffusion and Perfusion Imaging Evaluation for
Understanding Stroke Evolution 3) 6-16 HOURS
Patients treated with MT at a median of 11 hours after onset had a 28% increase
in functional independence and an additional 20% absolute reduction in death or
severe disability.
TRIALS SHOWING SUPERIORITY OF LATE MT # OVER standard
care
18. Mechanical Thrombectomy: Over 6 hours
Eligibility criteria based upon the DEFUSE 3 trial for patients who can start
treatment (femoral puncture) within 6 to 16 hours
Deficit on the NIHSS of ≥ 6 points
Prestroke baseline mRS score ≤2
Intracranial arterial occlusion of ICA or M1 segment of the MCA
A target mismatch profile on CT perfusion or MRI defined as an ischemic
core volume <70 ml, a mismatch ratio (penumbra/ischemic core) >1.8, and a
mismatch volume (penumbra-ischemic core) >15 mL
Age 18 to 90 years
19. Mechanical Thrombectomy: Over 6 hours
Eligibility criteria based upon DAWN trial for patients who can start treatment
(femoral puncture) within 6 to 24 hours
NIHSS of ≥10 points
Prestroke disability: baseline modified Rankin scale (mRS) score ≤1
Intracranial arterial occlusion of ICA or M1 segment of the MCA
A clinical-core mismatch according to age:
NIHSS ≥10 and an infarct volume <21 mL
NIHSS 10 to 19 and an infarct volume <31 mL
NIHSS ≥20 and an infarct volume <51 Ml
Normally NIHSS >15 a/w infarct volume of >56ml, 8-13 will have 32 ml
and 1-7 will have 8ml infarct volume.
Clinical core mismatch indicates salvageable tissue(penumbra)
20. MT IN POSTERIOR CIRCULATION
STROKE
BEST- RCT TRAIL comparing MT with standard medical care for patients
with acute vertebra basilar occlusion who could be treated within eight hours
Was stopped early for slow recruitment and high crossover rate after enrolling 131
patients
Compared with standard medical care, patients assigned to endovascular
therapy had similar rates of favorable outcome and 90-day mortality by intention-
to-treat analysis.
21. MT IN POSTERIOR CIRCULATION
STROKE
BASICS trial
300 patients with acute ischemic stroke attributed to basilar artery occlusion,
there was no statistically significant difference in outcomes for endovascular
therapy compared with medical therapy .
However, there was a non significant trend of benefit with endovascular treatment in
both trial.
22. MT IN POSTERIOR CIRCULATION
STROKE
BAOCHE trial -Basilar Artery Occlusion Chinese Endovascular was presented at
the European Stroke Organisation Conference2022 on May 6.
ATTENTION trial- was presented at the same meeting, also showing a benefit of
MT in patients with basilar artery occlusion stroke.
The two trials, which were both conducted in China, differed slightly in that
ATTENTION recruited patients presenting within 12 hours of stroke onset
whereas BAOCHE enrolled patients in the 6- to 24-hour time window.
Both trials have shown remarkably similar results, with large increases in the
number of patients achieving favorable functional outcomes when treated with
thrombectomy.
23. Mechanical thrombectomy-Procedure
Treatment of choice for acute ischemic stroke patients with proximal MCA
or ICA occlusion.
2 techniques :- a) Stent retriever devices
b) Aspiration devices
24.
25. SBP between
150 to 180
mmhg prior to
reperfusion
Can be done
under general
anesthesia or
conscious
sedation
Post procedure
BP <140mmhg
26.
27. Limitations of MT
Only an estimated 10 percent of patients with acute ischemic stroke have a
proximal large artery occlusion in the anterior circulation present early enough to
qualify for MT within 6 hours
9 percent of patients presenting in the 6 to 24 hour time window may qualify for
MT
Only a few stroke centers have sufficient resources and expertise to deliver this
therapy
32. Conclusion
Intravenous thrombolysis with i.v tPA – within 4.5hours
If treatment can be initiated within 6 hours there is no need for additional
imaging like perfusion studies.
The time window for EVT is 24 hours
33. References
Endovascular Treatment of Acute Ischemic Stroke By Gisele S. Silva, MD, MPH, PhD;
Raul G. Nogueira, MD CONTINUUM - 2020; 310–331
Endovascular Treatment of Acute Ischemic Stroke in Clinical Practice: Analysis of
Workflow and Outcome in a Tertiary Care Center Karin Weissenborn frontiers
neurology june 2021
AHA guidelines –secondary prevention of stroke 2021
Mechanical thrombectomy for acute ischemic stroke Up To Date
Bradley and Deroffs neurology in clinical practice 8th edition