POST-VACCINE-INDUCED IMMUNE THROMBOTIC THROMBOCYTOPENIA (VITT) STROKE: LITERATURE REVIEW AND PROPOSAL OF A THERAPEUTIC ALGORITHM FOR THE ACUTE PHASE

Background and aims: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but catastrophic syndrome characterized by venous and arterial thrombosis, with thrombocytopenia and antibodies against platelet factor-4 (PF4)/polyanion, typically 5-30 days from the first dose of a DNA viral vector vaccine. Very rarely, acute ischemic stroke (AIS) can be the result of VITT. The aim of this study was to define the clinical and radiological characteristics, outcome and therapeutic options of VITT patients with AIS. Methods: We carried out a systematic review of the literature till October 27, 2021 using MEDLINE, PUBMED and Google Scholar databases in order to collect all the published articles related to the development of AIS after vaccination against SARS-CoV-2. Results: We identified 16 patients from case reports or case series published in peer-reviewed journals affected by AIS and confirmed VITT. All patients had received the first dose of ChAdOx1 ncov19 vaccine within 10 days (median). 81% (n=13/16) of the patients had occlusion of the middle cerebral artery (MCA) or its branches, 43.7% (n=7/16) also had thrombotic occlusion of the intracranial internal carotid artery. 45.4% (n=5/16) of the patients with proximal MCA occlusion developed a malignant MCA infarct. Only one patient received intravenous thrombolysis, while three patients underwent mechanical thrombectomy. Conclusions: The management of AIS due to large vessel occlusion in VITT is challenging. Based on the available literature, we propose a therapeutic protocol for acute stroke patients presenting to the Emergency Department within the time window for reperfusion strategies.

Endovascular Reperfusion of Acute Large Vessel Occlusion Stroke

Acute stroke treatment continues to evolve with optimization of systemic intravenous thrombolysis and endovascular mechanical thrombectomy (MT) for intracranial large vessel occlusion (LVO). Neurointerventional techniques to achieve reperfusion in acute LVO stroke initially involved local intra-arterial infusion of thrombolytic agents. The subsequent development of MT devices has resulted in more complete and faster arterial recanalization while maintaining patient safety. Today, MT is standard of care for LVO stroke up to 24 h from last known well. In this chapter, we discuss various endovascular recanalization techniques for LVO stroke with illustrative cases.