A short history of thrombectomy - Procedure and success analysis of different endovascular stroke treatment techniques.

BACKGROUND: The historical development of interventional stroke treatment shows a wide variation of different techniques and materials used. Thus, the question of the present work is whether the technical and procedural differences of thrombectomy techniques lead to different technical and clinical results. METHODS AND RESULTS: Analysis of a mixed retrospective/prospective database of all endovascular treated patients with an occlusion of the Carotid-T or M1 segment of the MCA at a single comprehensive stroke center since 2008. Patients were classified regarding the technical approach used. Six hundred sixty-eight patients were available for the final analysis. Reperfusion rates ranged between 56% and 100% depending on the technical approach. The use of balloon guide catheters and most recently the establishment of combination techniques using balloon guide catheters, aspiration catheters and stent retrievers have shown a further significant increase in the rates of successful recanalization, full recanalization and first-pass recanalization. Additionally, the technical development of interventional techniques has led to a subsequent drop in complications, embolization into previously unaffected territories in particular. CONCLUSION: Technical success of MT has improved substantially over the past decade owing to improved materials and procedural innovations. Combination techniques including flow modulation have emerged to be the most effective approach and should be considered as a standard of care.Level of evidence: Level 3, retrospective study.

The Impact of Histological Clot Composition in Embolic Stroke.

PURPOSE: Thrombus composition has been suggested to have a decisive impact on the outcome of patients treated by mechanical thrombectomy because of embolic stroke. The recent development of stent retrievers allows collection and, hence, histopathological analysis of fresh thrombus material. Against this background, the aim of this prospective study was to assess the impact of thrombus composition on mechanical recanalization, clinical outcome and stroke etiology. METHODS: Thirty-four patients suffering from acute ischemic stroke due to occlusion of the distal internal carotid artery/carotid-T, anterior cerebral artery, or middle cerebral arteries were mechanically recanalized, and thrombus material was obtained. Histological thrombus composition was compared with imaging, clinical, and neurointerventional data. RESULTS: The main findings were that a higher percentage of white blood cells (WBCs) in the thrombus was associated with (i) cardioembolic etiology, (ii) extended mechanical recanalization time, and (iii) less favorable recanalization (Thrombolysis in Cerebral Infarction score) and clinical outcome (National Institute of Health Stroke Scale). CONCLUSION: Our results suggest that thrombi with a high WBC fraction are related to more organized thrombi of cardioembolic origin associated with less favorable recanalization and clinical outcome in acute ischemic anterior circulation stroke. WBC-mediated immunological and coagulatory processes may play a key role in thrombus formation and pathogenesis of stroke warranting further investigation.