Letter by Ng et al Regarding Article, “Cervical Carotid Pseudo-Occlusions and False Dissections: Intracranial Occlusions Masquerading as Extracranial Occlusions”

HomeStrokeVol. 48, No. 6Letter by Ng et al Regarding Article, “Cervical Carotid Pseudo-Occlusions and False Dissections: Intracranial Occlusions Masquerading as Extracranial Occlusions” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Ng et al Regarding Article, “Cervical Carotid Pseudo-Occlusions and False Dissections: Intracranial Occlusions Masquerading as Extracranial Occlusions” Felix Ng, MBBS, MPH Mineesh Datta, MBBS, FRANZCR Philip M. Choi, MBChB, FRACP Felix NgFelix Ng Department of Neurosciences, Eastern Health, Melbourne, Victoria, Australia Search for more papers by this author Mineesh DattaMineesh Datta Medical Imaging, Eastern Health, Melbourne, Victoria, Australia Search for more papers by this author Philip M. ChoiPhilip M. Choi Department of Neurosciences, Eastern Health, Melbourne, Victoria, Australia, Eastern Health Clinical School, Monash University, Melbourne, Victoria, Australia Search for more papers by this author Originally published28 Apr 2017https://doi.org/10.1161/STROKEAHA.117.016985Stroke. 2017;48:e140Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: January 1, 2017: Previous Version 1 To the Editor:We read with interest the recent study of Grossberg et al1 on cervical carotid pseudo-occlusion (PO) showing that PO is relatively common in patients with isolated intracranial internal carotid artery occlusion. We are writing to further highlight the clinical relevance of this poorly recognized entity and the need for an alternative noninvasive diagnostic modality for early detection.Misdiagnoses of PO as true occlusions may affect acute clinical decision making in the era of endovascular clot retrieval. When a chronic carotid occlusion is incorrectly suspected, or when a technically challenging procedure too prolonged for timely reperfusion is erroneously anticipated, eligible candidates may be denied urgent invasive angiographic assessment altogether because of presumed futility. This is particularly relevant for patients at Primary Stroke Centers where decisions on interhospital transfer for endovascular clot retrieval may be heavily influenced by findings on initial noninvasive imaging. A reliance on invasive angiography as the sole diagnostic modality will underdiagnose PO in such patients and potentially affect their care adversely.We recently reported the use of perfusion-derived 4-dimensional computed tomographic angiography (4D-CTA) as a novel noninvasive modality to identify PO in the acute stroke setting.2 Using the extended image acquisition time span of computed tomographic perfusion, 4D-CTA captures delayed antegrade flow through the apparently occluded PO segment, which may only opacify after a 50-second delay. The advantage of 4D-CTA compared with other noninvasive imaging is that it can be rapidly reconstructed from routine computed tomographic perfusion data without additional image acquisition or contrast administration and can be easily incorporated into an existing acute stroke multimodal computed tomographic protocol.The use of 4D-CTA as part of routine imaging in hyperacute stroke hence allows immediate differentiation of PO from tandem occlusion to aid interhospital transfer and endovascular clot retrieval decision making. In addition, 4D-CTA may further identify underlying critical carotid stenosis with trickle-flow as a contributory pathology to the PO flow-related artifact.3The true prevalence and clinical importance of PO will emerge as acute vascular imaging becomes a standard of care in the endovascular clot retrieval-era. Future studies evaluating the diagnostic accuracy of 4D-CTA and other noninvasive imaging modalities against microcatheter exploration as the gold standard will help determine the optimal diagnostic protocol to detect PO.Felix Ng, MBBS, MPHDepartment of NeurosciencesEastern HealthMelbourne, Victoria, AustraliaMineesh Datta, MBBS, FRANZCRMedical ImagingEastern HealthMelbourne, Victoria, AustraliaPhilip M. Choi, MBChB, FRACPDepartment of NeurosciencesEastern HealthMelbourne, Victoria, AustraliaEastern Health Clinical SchoolMonash UniversityMelbourne, Victoria, AustraliaDisclosuresNone.FootnotesStroke welcomes Letters to the Editor and will publish them, if suitable, as space permits. Letters must reference a Stroke published-ahead-of-print article or an article printed within the past 4 weeks. The maximum length is 750 words including no more than 5 references and 3 authors. Please submit letters typed double-spaced. Letters may be shortened or edited.References1. Grossberg JA, Haussen DC, Cardoso FB, Rebello LC, Bouslama M, Anderson AM, et al. Cervical carotid pseudo- occlusions and false dissections: intracranial occlusions masquerading as extracranial occlusions.Stroke. 2017; 48:774–777. doi: 10.1161/STROKEAHA.116.015427.LinkGoogle Scholar2. Ng FC, Choi PM, Datta M, Gilligan A. Perfusion- derived dynamic 4D CT angiography identifies carotid pseudo- occlusion in hyperacute stroke.J Neuroimaging. 2016; 26:588–591. doi: 10.1111/jon.12375.CrossrefMedlineGoogle Scholar3. Ng FC, Datta M, Choi PM. Time- resolved 4- dimensional computed- tomography angiography can correctly identify carotid pseudo- occlusion.J Stroke Cerebrovasc Dis. 2016; 25:1005–1006. doi: 10.1016/j.jstrokecerebrovasdis.2016.01.036.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails June 2017Vol 48, Issue 6 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/STROKEAHA.117.016985PMID: 28455325 Originally publishedApril 28, 2017 PDF download Advertisement SubjectsCerebrovascular Disease/StrokeComputerized Tomography (CT)Diagnostic TestingEmbolismStenosis