Relationship between thrombus composition and prognosis in patients with acute ischemic stroke undergoing mechanical thrombectomy

•In this study, we conducted a retrospective analysis of histopathological examination of retrieved thrombi from 50 patients with acute ischemic stroke. Our aim was to assess the composition of endovascularly retrieved thrombi and its relationship with the clinical outcomes of mechanical thrombectomy.•In this study, we found tha the composition of the thrombus can play a significant role in determining the thrombectomy strategy for endovascular therapy. Erythrocyte-rich thrombi were found to be associated with shorter time intervals from puncture to reperfusion. No significant differences were observed in the RBC fraction and fibrin fraction between large artery atherosclerosis and cardioembolism. Furthermore, patients with erythrocyte-rich thrombi exhibited more favorable clinical outcomes compared to those with fibrin-rich thrombi. Mechanical thrombectomy has emerged as the primary endovascular treatment for acute ischemic stroke. Numerous studies have investigated the relationship between thrombus composition and factors such as pharmacological thrombolysis, stroke etiology, mechanical thrombectomy, and radiological imaging. However, limited research has explored the association between thrombus composition and clinical outcomes. This retrospective analysis examined the histopathological examination of thrombi retrieved from 50 patients with acute ischemic stroke between May 2020 and May 2023. The composition of the retrieved thrombi was assessed using HE staining to quantify the proportions of red blood cells, white blood cells, platelets, and fibrin. Based on the predominant composition of the thrombus, the patients were divided into two groups: erythrocyte-rich and fibrin-rich. Demographics, clinical characteristics, and clinical outcomes assessed by the National Institutes of Health Stroke Scale (NIHSS) score and modified Rankin Scale (mRS) scores were collected retrospectively. Of the 50 patients, 23 were classified in the erythrocyte-rich group, and 27 were classified in the fibrin-rich group. There were no significant differences between the two groups in terms of age, sex, stroke subtype, history of hypertension and diabetes, thrombus location, NIHSS scores, mRS scores on admission, the time interval from symptom onset to hospitalization and reperfusion, or the rate of successful reperfusion. However, erythrocyte-rich thrombi were associated with a shorter time interval from puncture to reperfusion. No significant differences were found in the r