The Impact of Full Collapse on the Risk of Ischaemic Stroke in Patients with Carotid Near-Occlusion

Carotid near occlusion (CNO) is a severe carotid stenosis associated with a reduction in the calibre of the extracranial internal carotid artery distal to the stenosis. 1 Johansson E. Fox A. Carotid near-occlusion: a comprehensive review, part 1—definition, terminology, and diagnosis. AJNR Am J Neuroradiol. 2016; 37: 2-10 Crossref PubMed Scopus (49) Google Scholar The risk of ipsilateral stroke in patients with CNO is a controversial issue. While a post hoc analysis of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) reported a lower risk of ipsilateral stroke for medically treated patients with CNO compared with patients with severe (70–99%) carotid stenosis 2 Fox A.J. Eliasziw M. Rothwell P.M. Schmidt M.H. Warlow C.P. Barnett H.J.M. Identification, prognosis, and management of patients with carotid artery near occlusion. AJNR Am J Neuroradiol. 2005; 26: 2086-2094 PubMed Google Scholar , more recent studies have shown that the CNO recurrence rate may be higher. 3 Johansson E. Öhman K. Wester P. Symptomatic carotid near-occlusion with full collapse might cause a very high risk of stroke. J Intern Med. 2015; 277: 615-623 Crossref PubMed Scopus (37) Google Scholar ,4 Gu T. Aviv R.I. Fox A.J. Johansson E. Symptomatic carotid near-occlusion causes a high risk of recurrent ipsilateral ischemic stroke. J Neurol. 2020; 267: 522-530 Crossref PubMed Scopus (23) Google Scholar The lack of a clear CNO definition may have led to heterogeneous cohorts, which could explain this disparity in results.