The clinical manifestations of proximal (extracranial) internal carotid artery occlusions (pICAOs) may range from asymptomatic to acute, large, and devastating ischemic strokes. The etiology and ...pathophysiology of the occlusion, intracranial collateral status and patient’s premorbid status are among the factors determining the clinical presentation and outcome of pICAOs. Rapid and accurate diagnosis is crucial and may be assisted by the combination of carotid and transcranial duplex sonography, or a computed tomography/magnetic resonance angiography (CTA/MRA). It should be noted that with either imaging modalities, the discrimination of a pseudo-occlusion of the extracranial internal carotid artery (ICA) from a true pICAO may not be straightforward. In the absence of randomized data, the management of acute, symptomatic pICAOs remains individualized and relies largely on expert opinion. Administration of intravenous thrombolysis is reasonable and probably beneficial in the settings of acute ischemic stroke with early presentation. Unfortunately, rates of recanalization are rather low and acute interventional reperfusion therapies emerge as a potentially powerful therapeutic option for patients with persistent and severe symptoms. However, none of the pivotal clinical trials on mechanical thrombectomy for acute ischemic stroke randomized patients with isolated extracranial large vessel occlusions. On the contrary, several lines of evidence from non-randomized studies have shown that acute carotid endarterectomy, or endovascular thrombectomy/stenting of the ICA are feasible and safe, and pοtentially beneficial. The heterogeneity in the pathophysiology and clinical presentation of acute pICAOs renders patient selection for an acute interventional treatment a complicated decision-making process. The present narrative review will outline the pathophysiology, clinical presentation, diagnostic challenges, and possible treatment options for pICAOs.
Reperfusion of the ischemic brain parenchyma with intravenous thrombolysis and/or mechanical thrombectomy is the cornerstone of acute ischemic stroke treatment. A paradigm shift from “time is brain” ...to a more precision medicine approach now called “imaging is brain”, has taken place during the last decade. This transformation has been fueled by the progress in neuroimaging. Advanced Neuroimaging incorporates perfusion imaging in order to depict real-time cerebral perfusion disturbances and provide maps of the penumbra and ischemic core that will inform individualized clinical decisions. Advance neuroimaging has now a fundamental role in triaging patients that will receive reperfusion treatments beyond the conventional time windows of 4.5 hours for intravenous thrombolysis and 6 hours for mechanical thrombectomy. We provide a narrative review of all the pivotal observational studies and randomized-controlled clinical trials that supported the use of advance neuroimaging, as well as technical issues and pitfalls that may be useful for its implementation in routine clinical practice.
