Thrombi in Acute Stroke Patients: Histopathological Analysis after Mechanical Thrombectomy

Abstract Background The introduction of stent retrievers has made the complete extraction and histological analysis of human thrombi possible, although many studies have evaluated the retrieved thrombus by mechanical thrombectomy to assess its impact on success of acute stroke treatment, the results remain controversial, in this study we attempt to assess the impact of thrombus composition on mechanical recanalization, clinical outcome and stroke etiology. Objective Study the histopathological composition of thrombi extracted from acute stroke patients through mechanical thrombectomy, and correlate the findings with the causes of stroke, the imaging findings as well as thrombectomy efficacy in terms of the number of recanalization maneuvers, retrieval resistance, and time to achieve successful reperfusion. Patients and Methods The study was carried out at Ain Shams University hospitals to Patients presented to emergency department with large vessel occlusion and were candidate for mechanical thrombectomy. Participants were selected as sample sizes of 26 according to those meeting the inclusion Criteria for participant: patients with acute ischemic stroke with evidence of middle cerebral artery occlusion or internal carotid artery occlusion confirmed via cerebral angiography, Age ≥ 18 years old, NIHSS ≥ 6, Aspect score ≥ 6, time from onset to groin puncture is Within 24 hours, Patients for whom cerebral thrombus could be retrieved and collected during mechanical thrombectomy for histopathological analysis, and Agreement for written informed consent for participation or their nearest relatives in this study). Results In our study, Erythrocyte-rich thrombi were present in 16 cases, while fibrin-rich thrombi were present in 5 cases. A cardioembolic etiology was significantly more prevalent among the patients with erythrocyte-rich thrombi than among those with fibrin/platelet and a P- value of < 0.001. Puncture to final reperfusion time was significantly highest in cases with RBC-rich with P-value of < 0.001, and Number of passes needed to achieve reperfusion was significantly highest in cases with RBC-rich with P-value 0.002. Conclusion The current study showed Erythrocyte-rich thrombi were associated with a reduced number of recanalization maneuvers, shorter arrival-to-recanalization time interval, and more favorable clinical outcomes. This study also suggests that the histological composition of retrieved thrombi is significantly different between stroke subtypes. Cardioembolic thrombi have a higher percentage of erythrocytes and fewer fibrin/platelet than do non cardioembolic thrombi.