Transcranial Doppler After Endovascular Treatment to Evaluate Collateral Status and Outcomes in Patients With Large-Vessel Occlusion.

Background: Recent advances in endovascular therapy (EVT) have led to significant improvements in functional outcomes of patients with stroke. However, early neurological deterioration after EVT has remained a concerning issue. This cohort study was designed to assess the feasibility of early transcranial Doppler (TCD) after EVT and to identify associations between TCD findings and early neurological deterioration. Methods: Between October 16, 2020, and March 28, 2021, we recruited 20 patients with acute ischemic stroke with large-vessel occlusion who underwent EVT. Five patients were excluded because of a poor temporal window; 2 had an unsuccessful intervention. Using TCD, we measured peak systolic velocity, end-diastolic velocity, mean flow velocity, and pulsatility index for all selected arteries before and within 60 minutes after EVT. We also examined the association between active leptomeningeal collateral flow after EVT and early neurological deterioration. Patients were followed for 3 months, and disability was measured using the modified Rankin scale. Results: Two patients had early neurological deterioration with elevated blood pressure and active leptomeningeal flow despite successful EVT. Most patients with poststroke disability (modified Rankin scale>2) had either flow diversion or active leptomeningeal collateral flow in the presence of elevated blood pressure (≥170/93 mm Hg). In cases without early neurological deterioration and in those with a modified Rankin scale<2, we did not observe any flow diversion or active leptomeningeal collateral. They also had a blood pressure of ≤155/85 mm Hg after EVT. All patients with hemorrhagic transformation had evidence of hyperemia on TCD. Conclusions: Early TCD is a feasible and safe approach to evaluate cerebral blood flow before and after EVT and identify those at risk of early neurological deterioration. For the next phase of this study, we plan to manage blood pressures based on individualized cerebral flow and the presence of active collateral arteries after EVT.