Clinical Research Directory

TCD measurement will be collected with TCD low frequency MHz probes. All TCD operations will be performed by a trained sonographer to assess bilateral MCA, ACA, PCA, Siph, and OA. TCD examinations will be performed as soon as possible after EVT, daily for 3 days and, when possible, as close to any reported neurological deterioration or CT brain scan performed within 72 hours of EVT.

TCD parameters are PSV, EDV, MFV, and PI. Sampling volume will be 5-10 mm, and the monitoring depth on transtemporal windows will be adjusted to gather appropriate vessel segment, e.g. 20-30 mm in the leptomeningeal flow, 40-50 mm in the distal MCA, 50-60 mm in the proximal MCA, 70-75 mm in the ACA, 62-70 mm in PCA, and transorbital, including 60-64 mm in the Siph and 50-60 mm in the OA. TAMMV and PI will be automatically derived from preset. Additionally, flow diversion will be assessed as an indirect indicator of arterial occlusion or severe stenosis in the middle cerebral artery (M1). It will be identified by TCD based on the following criteria: (1) low-resistance flow pattern in the anterior or posterior cerebral artery, and (2) mean flow velocity in the ACA or PCA greater than or equal to that in the MCA.

Baseline characteristics will be collected, including age, sex, ethnicity, history of HTN, DM, DLP, CHF, AF, CA, CKD, previous CAD, cirrhosis, mRS, previous stroke or TIA, current antiplatelet usage, current anticoagulant usage, smoking, and alcohol status. This data will be collected through a combination of verbal interviews with participants/LAR legally authorized representatives and a review of their medical history charts.

Clinical data will be collected, including blood pressure values before, during, and after TCD as well as, Door to needle, Door to groin, Groin to first pass, time from recanalization to TCD, baseline NIHSS, site of occlusion, infarct core volume, mismatch volume, mismatch ratio, and IVT treatment status. Classification of stroke etiologies will be collected based on widely accepted TOAST criteria categorized in large vessel atherosclerosis (LAA), cardio-embolism (CE), small vessel occlusion (SAO), Stroke of other determined etiology (SOC), and stroke of undetermined etiology (SUC) \[30\]. This data will be collected by reviewing medical charts from EHR coded as part of standard care.

All follow-up patients receive a phone call as part of standard post thrombectomy care from the stroke nurses to gather modified Rankin Scale at 7 days and 90 days since hospital discharge.