TCD Monitoring Technology Guides the Precise Control of Blood Pressure After EVT

Investigators hypothesized that the precise regulation of blood pressure based on the changes of cerebral blood flow parameters under TCD monitoring can better improve the state of cerebral blood flow, reduce the risk of early neurological deterioration and improve the prognosis of the patients.

Accurate monitoring of blood pressure is carried out under TCD monitoring, that is to maintain （mean flow velocity）MFV or （pulse index）PI target blood pressure. The target values of MFV and PI are MFV>37cm/s of （middle cerebral artery)MCA, PI < 1.34cm/s, aMFV>40cm/s of (basilar artery)BA, PI < 0.8cm/s. TCD shows that when the MFV of MCA or BA is lower than the target value, the blood pressure is reduced or discontinued according to the insufficiency of blood flow. and the current blood pressure is maintained once MFV is met. TCD showed that the PI index of MCA or BA was higher than the target value . The blood pressure reduction was treated by excessive perfusion: intravenous infusion of blood pressure drugs , once PI index is up to the standard, maintaining the current blood pressure.

the incidence of 72 hours in National Institute of Health stroke scale increased more than 4 points or National Institute of Health stroke scale Ia score more than 1 points

prognosis of nerve function use Modified Rankin Scale,0~3 is good prognosis and 4~6 is poor prognosis.

Inclusion Criteria: 18 years of age or older; accept EVT treatment within 6 hours of symptoms onset; In selected patients with AIS within 6 to 16 hours of last known normal who have LVO in the anterior circulation and meet other DAWN or DEFUSE 3 eligibility criteria.. In selected patients with AIS within 6 to 24 hours of last known normal who have LVO in the anterior circulation and meet other DAWN eligibility criteria. Exclusion Criteria: Pre - onset mRS>2; severe dementia; threatening life diseases (such as malignant tumor, etc.); non acute ischemic cerebrovascular disease patients undergoing selective intravascular treatment; related sound window closure can not be monitoring with TCD.