Prognostic Role of Microembolic Signals After Endovascular Treatment in Anterior Circulation Ischemic Stroke Patients

Background Endovascular treatment (EVT) is an effective therapy for acute ischemic stroke due to large artery occlusion of the anterior circulation. Yet some patients do not experience clinical improvement despite successful recanalization and reperfusion. The reasons are unknown, but one possible explanation is microvessel obstruction downstream. The aim of this study was to assess the presence of microembolic signals (MES) with transcranial Doppler and define their role as predictors of clinical outcome in stroke patients after EVT. Materials and Methods We enrolled 40 consecutive patients (23 men, mean age 65.8 ± 7.6 years) with an acute ischemic stroke caused by large artery occlusion of the anterior circulation who underwent EVT. Presence and rate of MES were assessed by 60-minute transcranial Doppler monitoring at the end of the procedure and after 15 days from stroke onset. Results MES were detected in 65% (26/40) of patients after EVT. Ipsilateral carotid occlusion (P = 0.05), ≥50% ipsilateral carotid stenosis (P = 0.05), incomplete recanalization (P = 0.03), and inadequate collaterals (P = 0.04) were associated with a significantly higher MES count, which was correlated with a worse functional prognosis (P = 0.03), higher mortality (P = 0.02), higher distal embolization burden even outside the original ischemic territory (P = 0.02), and higher risk of cardiovascular events (P = 0.04). Conclusions MES monitoring in stroke patients after EVT provides useful prognostic information, sheds light on the lack of clinical improvement despite successful recanalization, and might guide medical treatment in higher risk patients.