Impressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia

Impressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Impressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia Quiceno-Ramirez Santiago, Maria Alejandra Recio-Gómez, Juliana Alarcón, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8554622/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Mar, 2026 Read the published version in Neuroradiology → Version 1 posted You are reading this latest preprint version Abstract Anatomical variants of the cervicocranial vasculature are rare and usually incidental findings. However, their identification is crucial due to their association with other neurovascular pathologies and their profound impact on surgical planning. We report the case of an 84 year-old patient who underwent computed tomography angiography for a suspected stroke. The study incidentally revealed the coexistence of two extremely rare vascular anomalies: agenesis of the left internal carotid artery and a right vertebral artery with a retroesophageal course. This exceptional finding emphasizes the fundamental role of modern imaging techniques in the diagnosis of these entities, which is essential for a correct interpretation of the patient's symptoms, preventing iatrogenic complications during interventional procedures, and understanding altered cerebral hemodynamics. Internal carotid artery vertebral artery vascular anomaly computed tomography angiotrophy Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Anatomical variants of the cervicocranial vasculature are often clinically silent and frequently identified as incidental findings. However, two key considerations exist: first, their described association with other entities, such as arteriovenous malformations or cerebral aneurysms; and second, their significant impact on surgical planning, especially in neurovascular procedures ( 1 ). Contemporary imaging techniques have made it possible to detect and characterize them with greater precision, which highlights their importance in current radiological practice. The internal carotid artery (ICA) may present structural abnormalities such as agenesis, aplasia, or hypoplasia. These are infrequent findings, usually described in asymptomatic patients. In particular, ICA agenesis has an incidence of less than 0.01%, and its limited clinical impact is usually attributed to the adequate collateral circulation provided by the circle of Willis and other intracranial anastomoses ( 2 ) However, in some cases it can manifest with neurological symptoms secondary to intracranial aneurysms or cerebral ischemia ( 3 ). Similarly, vertebral anatomy can also present rare variants. One of the rarest is the aberrant vertebral artery, or “vertebral arteria lusoria”, characterized by an origin distal to that of the left subclavian artery in the aortic arch and a retroesophageal course. The incidence of this variant is extremely low, with only 66 cases reported since the 19th century ( 4 ). In this context, we report an exceptional case of a patient in the ninth decade of life in whom CT angiography incidentally revealed the coexistence of a vertebral arteria lusoria with agenesis of the left internal carotid artery, identified during the evaluation of an acute neurological deficit. Case presentation An 84-year-old male patient with a history of hypothyroidism, hypertension, and coronary artery disease treated with stent placement one month prior to admission presented to the emergency department after a four-hour history of severe neck pain, followed by left hemiparesis and mild dysarthria, without altered mental status or other associated symptoms. On admission, he had elevated blood pressure, but all other vital signs were within normal range. Physical examination revealed an alert and oriented patient with no objective neurological deficits. His NIHSS score was 6, and his capillary blood glucose was 118 mg/dL. A non-enhanced CT scan was performed, followed by CT angiography of intracranial and cervical vessels, which ruled out infarction or acute hemorrhage. The report concluded an ASPECTS score of 10/10, no evidence of large vessel occlusion, territorial infarction or ischemic penumbra (Figure 1). Incidentally, agenesis of the left ICA was identified from its origin (Figure 2), as well as a vertebral arteria lusoria, originating distal to the left subclavian artery in the aortic arch, with a retroesophageal course (Figure 3). Cerebral magnetic resonance angiography (MRA) confirms that the entire anterior circulation originates from the right ICA (Figure 4). During his stay in the emergency room, the patient experienced worsening of neck pain, prompting a cervical spine MRI. The study revealed spondyloarthrosis-related degenerative changes with spinal stenosis at the C3–C4 and C4–C5 levels, without evidence of myelopathy. These findings were interpreted as the likely cause of the neck pain, unrelated to the initial motor deficit, which resolved spontaneously. The patient received pain management, with a satisfactory clinical course and no recurrence of motor symptoms during hospitalization until discharge. Discussion The coexistence of a right vertebral artery lusoria and agenesis of the left internal carotid artery is an exceptionally rare anatomical combination, which underscores the critical relevance of imaging in identifying vascular variants with clinical and surgical implications. To the best of our knowledge, no previous reports of this association are available. Agenesis of the ICA occurs in less than 0.01% of the population. Its embryological origin lies in the aberrant development of the first and third aortic arches between the fourth and eighth weeks of gestation. This can be associated with an increased risk of intracranial aneurysms and secondary subarachnoid hemorrhage due to hemodynamic stress in the collateral circulation, primarily increased wall shear stress, and increased flow velocity in the anterior and posterior communicating arteries and other collateral vessels.( 2 ) Similarly, as in the case of our patient, this anatomical variant can predispose to presenting with neurological symptoms such as aphasia and hemiparesis secondary to a transient ischemic attack, due to either a decompensation in the intracranial collateral circulation or a decrease in cerebral perfusion caused by concomitant atherosclerotic disease.( 2 , 5 ). In a review by Zhang et al., who evaluated 54 patients reported in the literature with agenesis of at least one ICA, they found that those patients between 0 and 20 years of age presented with developmental delay (13/24, 52.2%), associated with abnormal development of the pituitary gland or its blood supply, or symptoms related to subarachnoid hemorrhage (6/24, 25%), demonstrating aneurysm formation and rupture secondary to hemodynamic changes. Patients between 25 and 45 years of age were predominantly asymptomatic, and the finding was made incidentally. For patients over 40 years of age, the main symptomatology was related to transient ischemic attacks (10/23, 43.5%), such as aphasia and hemiparesis, evident in the case presented, and this is associated with decompensated intracranial collateral circulation or decreased cerebral perfusion due to an atherosclerotic plaque.( 5 ). On the other hand, vertebral arteria lusoria is an extremely rare anomaly, typically originating from the proximal descending aorta and taking a retroesophageal course to reach the transverse foramen of C7.( 6 ) Gailloud conducted a systematic search using terms similar to "vertebral artery lusoria," finding 66 reported cases since 1859 with this finding. However, in none of these instances was it associated with clinical symptoms or cardiovascular abnormalities. Though this anomaly is expected to represent a higher risk of dissection or luminal injury along its course, its finding is usually incidental. There is also no evidence that vertebral arteries or aortic origin predispose to cerebrovascular disorders.( 7 ) Nevertheless, it does constitute a surgical risk of developing uncontrollable bleeding during esophageal or aortic procedures.( 4 ) Conclusion The coexistence of agenesis of the left internal carotid artery and a lusoria right vertebral artery is an exceptional anatomical finding. This case highlights the critical importance of advanced imaging techniques for identifying vascular variants that, although frequently asymptomatic, can have significant clinical implications, including potential surgical risks during neurovascular or esophageal interventions. Recognizing these anomalies is essential to guide clinical evaluation, prevent complications, and safely plan invasive procedures. Statements and Declarations Consent to publish The participant has consented to the submission of the case report to the journal. Funding or competing interests The authors have no relevant financial or non-financial interests to disclose. References Case D, Seinfeld J, Folzenlogen Z, Kumpe D (2015) Anomalous Right Vertebral Artery Originating from the Aortic Arch Distal to the Left Subclavian Artery: A Case Report and Review of the Literature. J Vasc Interv Neurol 8(3):21–24 Cohen JE, Gomori JM, Leker RR (2010) Internal carotid artery agenesis: diagnosis, clinical spectrum, associated conditions and its importance in the era of stroke interventions. Neurol Res 32(10):1027–1032 Paşaoğlu L, Vural M, Ziraman I, Uyanιk SA (2011) Left internal carotid artery agenesis associated with basilar and left vertebral artery aneurysm. J Clin Imaging Sci 1:60 Gailloud P (2024) Vertebral arteria lusoria-Hyrtl’s original description (1859), case illustration, and literature analysis. Surg Radiol Anat 46(10):1633–1642 Zhang P, Wang Z, Yu FX, Lv H, Liu XH, Feng WH et al (2018) The clinical presentation and collateral pathway development of congenital absence of the internal carotid artery. J Vasc Surg 68(4):1054–1061 Yuan SM (2016) Aberrant Origin of Vertebral Artery and its Clinical Implications. Braz J Cardiovasc Surg 31(1):52–59 Lazaridis N, Piagkou M, Loukas M, Piperaki ET, Totlis T, Noussios G et al (2018) A systematic classification of the vertebral artery variable origin: clinical and surgical implications. Surg Radiol Anat 40(7):779–797 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 17 Mar, 2026 Read the published version in Neuroradiology → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8554622","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":575089116,"identity":"6f24cde2-4371-4027-855a-39e909f3ffd6","order_by":0,"name":"Quiceno-Ramirez 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14:07:29","extension":"html","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":28115,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/c1931e1924c73eb74bea1337.html"},{"id":100409503,"identity":"2347e6bf-6ef9-494f-91d9-1267095ed366","added_by":"auto","created_at":"2026-01-16 13:07:16","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":511433,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eNon-enhanced CT brain (A), relative cerebral blood volume map (B) and mean transit time map (C) with no evidence of established infarction, ischemic penumbra or acute hemorrhage in brain parenchyma.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/911894072a20379ee34409cc.png"},{"id":100422484,"identity":"ce1e25cb-8fab-458b-bfed-6540f1473021","added_by":"auto","created_at":"2026-01-16 14:08:06","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":295394,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eAngioCT of the neck and carotid vessels, showing absence of opacification of the left internal carotid artery from its bifurcation (A, white arrow) and in its petrous portion (B, red arrow). The carotid canal was never developed.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/b40f35ff23a8271831d7ef98.png"},{"id":100410903,"identity":"d904db0a-cc84-497e-a50a-04a6cac7f610","added_by":"auto","created_at":"2026-01-16 13:09:34","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":270805,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eCT angiography of the neck and carotid vessels (A and B) showing the origin of the right vertebral artery from the aortic arch (white arrow) with a retroesophageal course (yellow arrow), constituting an aberrant variant. (C) Axial oblique MIP reformat demonstrates the aortic origin of the artery. Cinematic rendering (D) demonstrating the aberrant vertebral artery course from its origin to the right vertebral foramina.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/fe5be5b6f1d12cdfc911756b.png"},{"id":100410046,"identity":"a944c4b5-df9a-4606-bae8-a1df292cddcc","added_by":"auto","created_at":"2026-01-16 13:07:44","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":336049,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eMRA brain showing absence of left internal carotid artery. ACAs: Anterior cerebral arteries. RMCA: Right middle cerebral artery. LMCA: Left middle cerebral artery. RICA: Right internal carotid artery. RPCA: Right posterior cerebral artery. LPCA: Left posterior cerebral artery. BA: Basilar artery. RVA: Right vertebral artery. LVA: Left cerebral artery. LECA: Left external carotid artery.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/b3148679ad860241251f0f54.png"},{"id":105223759,"identity":"8dc240a3-3004-41cc-9d9d-6888266100c5","added_by":"auto","created_at":"2026-03-23 16:10:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1992966,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8554622/v1/fdc1f894-f33e-4d7f-981e-aa24804b7ba4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eImpressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAnatomical variants of the cervicocranial vasculature are often clinically silent and frequently identified as incidental findings. However, two key considerations exist: first, their described association with other entities, such as arteriovenous malformations or cerebral aneurysms; and second, their significant impact on surgical planning, especially in neurovascular procedures (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Contemporary imaging techniques have made it possible to detect and characterize them with greater precision, which highlights their importance in current radiological practice.\u003c/p\u003e \u003cp\u003eThe internal carotid artery (ICA) may present structural abnormalities such as agenesis, aplasia, or hypoplasia. These are infrequent findings, usually described in asymptomatic patients. In particular, ICA agenesis has an incidence of less than 0.01%, and its limited clinical impact is usually attributed to the adequate collateral circulation provided by the circle of Willis and other intracranial anastomoses (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) However, in some cases it can manifest with neurological symptoms secondary to intracranial aneurysms or cerebral ischemia (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSimilarly, vertebral anatomy can also present rare variants. One of the rarest is the aberrant vertebral artery, or \u0026ldquo;vertebral arteria lusoria\u0026rdquo;, characterized by an origin distal to that of the left subclavian artery in the aortic arch and a retroesophageal course. The incidence of this variant is extremely low, with only 66 cases reported since the 19th century (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn this context, we report an exceptional case of a patient in the ninth decade of life in whom CT angiography incidentally revealed the coexistence of a vertebral arteria lusoria with agenesis of the left internal carotid artery, identified during the evaluation of an acute neurological deficit.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eAn 84-year-old male patient with a history of hypothyroidism, hypertension, and coronary artery disease treated with stent placement one month prior to admission presented to the emergency department after a four-hour history of severe neck pain, followed by left hemiparesis and mild dysarthria, without altered mental status or other associated symptoms. On admission, he had elevated blood pressure, but all other vital signs were\u0026nbsp;within normal range. Physical examination revealed an alert and oriented patient with no objective neurological deficits. His NIHSS score was 6, and his capillary blood glucose was 118 mg/dL.\u003c/p\u003e\n\u003cp\u003eA non-enhanced CT scan was performed, followed by CT angiography of intracranial and cervical vessels, which ruled out infarction or acute hemorrhage. The report concluded an ASPECTS score of 10/10, no evidence of large vessel occlusion, territorial infarction or ischemic penumbra (Figure 1).\u003c/p\u003e\n\u003cp\u003eIncidentally, agenesis of the left ICA was identified from its origin (Figure 2), as well as a vertebral arteria lusoria, originating distal to the left subclavian artery in the aortic arch, with a retroesophageal course (Figure 3).\u003c/p\u003e\n\u003cp\u003eCerebral magnetic resonance angiography (MRA) confirms that the entire anterior circulation originates from the right ICA (Figure 4).\u003c/p\u003e\n\u003cp\u003eDuring his stay in the emergency room, the patient experienced worsening of neck pain, prompting a cervical spine MRI. The study revealed spondyloarthrosis-related degenerative changes with spinal stenosis at the C3\u0026ndash;C4 and C4\u0026ndash;C5 levels, without evidence of myelopathy. These findings were interpreted as the likely cause of the neck pain, unrelated to the initial motor deficit, which resolved spontaneously. The patient received pain management, with a satisfactory clinical course and no recurrence of motor symptoms during hospitalization until discharge.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe coexistence of a right vertebral artery lusoria and agenesis of the left internal carotid artery is an exceptionally rare anatomical combination, which underscores the critical relevance of imaging in identifying vascular variants with clinical and surgical implications. To the best of our knowledge, no previous reports of this association are available.\u003c/p\u003e \u003cp\u003eAgenesis of the ICA occurs in less than 0.01% of the population. Its embryological origin lies in the aberrant development of the first and third aortic arches between the fourth and eighth weeks of gestation. This can be associated with an increased risk of intracranial aneurysms and secondary subarachnoid hemorrhage due to hemodynamic stress in the collateral circulation, primarily increased wall shear stress, and increased flow velocity in the anterior and posterior communicating arteries and other collateral vessels.(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eSimilarly, as in the case of our patient, this anatomical variant can predispose to presenting with neurological symptoms such as aphasia and hemiparesis secondary to a transient ischemic attack, due to either a decompensation in the intracranial collateral circulation or a decrease in cerebral perfusion caused by concomitant atherosclerotic disease.(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn a review by Zhang et al., who evaluated 54 patients reported in the literature with agenesis of at least one ICA, they found that those patients between 0 and 20 years of age presented with developmental delay (13/24, 52.2%), associated with abnormal development of the pituitary gland or its blood supply, or symptoms related to subarachnoid hemorrhage (6/24, 25%), demonstrating aneurysm formation and rupture secondary to hemodynamic changes. Patients between 25 and 45 years of age were predominantly asymptomatic, and the finding was made incidentally. For patients over 40 years of age, the main symptomatology was related to transient ischemic attacks (10/23, 43.5%), such as aphasia and hemiparesis, evident in the case presented, and this is associated with decompensated intracranial collateral circulation or decreased cerebral perfusion due to an atherosclerotic plaque.(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOn the other hand, vertebral arteria lusoria is an extremely rare anomaly, typically originating from the proximal descending aorta and taking a retroesophageal course to reach the transverse foramen of C7.(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e) Gailloud conducted a systematic search using terms similar to \"vertebral artery lusoria,\" finding 66 reported cases since 1859 with this finding. However, in none of these instances was it associated with clinical symptoms or cardiovascular abnormalities.\u003c/p\u003e \u003cp\u003eThough this anomaly is expected to represent a higher risk of dissection or luminal injury along its course, its finding is usually incidental. There is also no evidence that vertebral arteries or aortic origin predispose to cerebrovascular disorders.(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) Nevertheless, it does constitute a surgical risk of developing uncontrollable bleeding during esophageal or aortic procedures.(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe coexistence of agenesis of the left internal carotid artery and a lusoria right vertebral artery is an exceptional anatomical finding. This case highlights the critical importance of advanced imaging techniques for identifying vascular variants that, although frequently asymptomatic, can have significant clinical implications, including potential surgical risks during neurovascular or esophageal interventions. Recognizing these anomalies is essential to guide clinical evaluation, prevent complications, and safely plan invasive procedures.\u003c/p\u003e"},{"header":"Statements and Declarations","content":"\u003cp\u003e\u003cem\u003eConsent to publish\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe participant has consented to the submission of the case report to the journal.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFunding or competing interests\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCase D, Seinfeld J, Folzenlogen Z, Kumpe D (2015) Anomalous Right Vertebral Artery Originating from the Aortic Arch Distal to the Left Subclavian Artery: A Case Report and Review of the Literature. J Vasc Interv Neurol 8(3):21\u0026ndash;24\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCohen JE, Gomori JM, Leker RR (2010) Internal carotid artery agenesis: diagnosis, clinical spectrum, associated conditions and its importance in the era of stroke interventions. Neurol Res 32(10):1027\u0026ndash;1032\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaşaoğlu L, Vural M, Ziraman I, Uyanιk SA (2011) Left internal carotid artery agenesis associated with basilar and left vertebral artery aneurysm. J Clin Imaging Sci 1:60\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGailloud P (2024) Vertebral arteria lusoria-Hyrtl\u0026rsquo;s original description (1859), case illustration, and literature analysis. Surg Radiol Anat 46(10):1633\u0026ndash;1642\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang P, Wang Z, Yu FX, Lv H, Liu XH, Feng WH et al (2018) The clinical presentation and collateral pathway development of congenital absence of the internal carotid artery. J Vasc Surg 68(4):1054\u0026ndash;1061\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYuan SM (2016) Aberrant Origin of Vertebral Artery and its Clinical Implications. Braz J Cardiovasc Surg 31(1):52\u0026ndash;59\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLazaridis N, Piagkou M, Loukas M, Piperaki ET, Totlis T, Noussios G et al (2018) A systematic classification of the vertebral artery variable origin: clinical and surgical implications. Surg Radiol Anat 40(7):779\u0026ndash;797\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Internal carotid artery, vertebral artery, vascular anomaly, computed tomography angiotrophy","lastPublishedDoi":"10.21203/rs.3.rs-8554622/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8554622/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAnatomical variants of the cervicocranial vasculature are rare and usually incidental findings. However, their identification is crucial due to their association with other neurovascular pathologies and their profound impact on surgical planning. We report the case of an 84 year-old patient who underwent computed tomography angiography for a suspected stroke. The study incidentally revealed the coexistence of two extremely rare vascular anomalies: agenesis of the left internal carotid artery and a right vertebral artery with a retroesophageal course. This exceptional finding emphasizes the fundamental role of modern imaging techniques in the diagnosis of these entities, which is essential for a correct interpretation of the patient's symptoms, preventing iatrogenic complications during interventional procedures, and understanding altered cerebral hemodynamics.\u003c/p\u003e","manuscriptTitle":"Impressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-16 11:11:37","doi":"10.21203/rs.3.rs-8554622/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"dade569e-0c1d-4a97-925e-3da9fef2d1d3","owner":[],"postedDate":"January 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-23T16:06:49+00:00","versionOfRecord":{"articleIdentity":"rs-8554622","link":"https://doi.org/10.1007/s00234-026-03962-5","journal":{"identity":"neuroradiology","isVorOnly":false,"title":"Neuroradiology"},"publishedOn":"2026-03-17 15:59:02","publishedOnDateReadable":"March 17th, 2026"},"versionCreatedAt":"2026-01-16 11:11:37","video":"","vorDoi":"10.1007/s00234-026-03962-5","vorDoiUrl":"https://doi.org/10.1007/s00234-026-03962-5","workflowStages":[]},"version":"v1","identity":"rs-8554622","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8554622","identity":"rs-8554622","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}