General EVT Considerations
General Considerations for EVT - For Low ASPECTS - use your own judgment (pending revision of guidelines)
"General Considerations for EVT" Flow Chart:
Overall, for all vessel occlusions amenable for EVT, a discussion with INR is recommended. "General Considerations for EVT" follows a colour coding:
Green boxes are "signposts" of criteria to consider for EVT: baseline function, clinical, radiographic, and timing (last seen well) characteristics of the patient.
Purple boxes are consideration elements that warrant further discussion with INR as these patients do not automatically get considered for EVT.
Blue boxes represent patients that require an individualized approach.
The Yellow box represent patients that have met all previous criteria (Pre-stroke status, Signs and Severity of Deficit, Imaging criteria) and are candidates for EVT.
Please note detailed imaging criteria, listed below ("CSBPR 2018 Guidelines - Imaging Criteria for EVT") for patients within 6hrs and beyond 6hrs after stroke onset.
DAWN / DEFUSE 3 Criteria - to be used for > 6hr for EVT Consideration
RAPID Training (www.irapid.com/training-rapid)
Late EVT Window, Greater than 6 hours (6-24Hrs)
DEFUSE3 criteria
ICA or MCA-M1 occlusion (carotid occlusions can be cervical or intracranial; with or without tandem MCA lesions) by MRA or CTA AND
Target Mismatch Profile on CT perfusion or MRI (ischemic core volume is < 70 ml (CBF<30), mismatch ratio is >/= 1.8 and mismatch volume* is >/= 15 ml) Alternative neuroimaging inclusion criteria (if perfusion imaging or CTA/MRA is technically inadequate): If CTA (or MRA) is technically inadequate:
Tmax>6s perfusion deficit consistent with an ICA or MCA-M1 occlusion AND Target Mismatch Profile (ischemic core volume is < 70 ml, mismatch ratio is >1.8 and mismatch volume is >15 ml as determined by RAPID software)
DAWN criteria (core measured CBF<30)
0-<21 cc core infarct and NIHSS ≥ 10 (and age ≥ 80 years old)
0-<31 cc core infarct and NIHSS ≥ 10 (and age < 80 years old)
31 cc to <51 cc core infarct and NIHSS ≥ 20 (and age < 80 years old)
Lastly a word of caution. ALWAYS ensure you look at NCCT to assess hypo-density and correlate this with CBF core recalling that you may have a sub-acute infarct with luxury perfusion (therefore CBF>30 i.e. not showing as core on threshold to CBF map).
Graphic/table reference: Stroke, G. A., 2018. (n.d.). Use of Imaging to Select Patients for Late Window Endovascular Therapy. Am Heart Assoc. http://doi.org/10.1161/STROKEAHA.118.021011.)