Anatomy of vertebral artery hypoplasia and its relationship with clinical implications: a systematic review and meta-analysis of prevalence.

PURPOSE: The vertebral artery (VA) is a vital branch of the subclavian artery, coursing through the transverse foramina of the cervical vertebrae, and playing a crucial role in irrigating the posterior region of the arterial cerebral circle, also known as the Polygon of Willis. Among the various possible alterations that can affect the VA, vertebral artery hypoplasia (HAV) emerges as a significant variant. This study aims to discern the anatomical features of HAV and its correlation with the clinical conditions of the posterior cerebral circulation. METHODS: The databases Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS were searched until January 2024. Two authors independently performed the search, study selection, and data extraction. Methodological quality was evaluated with an assurance tool for anatomical studies (AQUA). Pooled prevalence was estimated using a random effects model. RESULTS: A total of 24 studies met the established selection criteria, with a total of 8847 subjects. In this study, 6 articles were included for the meta-analysis with a total of subjects. The average prevalence of VAH reported in each study was 11% (95% CI 10-12%); the studies had a heterogeneity of 41% based on the funnel plot and a low risk of bias. CONCLUSION: The prevalence of VAH is low, but in the presence of this condition, the changes are mainly in diameter rather than morphological. If it is present, some clinical safeguards must be taken to avoid complications such as stroke.

Bilateral Variation of the Vertebral Artery: Report of a Case and its Clinical Implication / Variación Bilateral de la Arteria Vertebral; Reporte de un Caso y su Implicancia Clínica

SUMMARY: There are many reports on anatomical variations of the vertebral arteries, which may be related to origin, trajectory, caliber, and side. Bilateral variations are less frequent, however, and less common are bilateral variants that differ from each other. The aim of this work was to report the presence of a bilateral variation of the vertebral artery and its functional and clinical implications. Dissection of a female cadaver, fixed in 10 % buffered formaldehyde, which had not undergone any previous surgeries in the study area and had anatomical variations in both vertebral arteries. In each one, follow-up was done from its origin to its end, determining its trajectory, diameters, branching, and anatomical relations. A left vertebral artery was found, starting in the aortic arch and making a sinuous trajectory of 4 curvatures to enter the transverse foramen of C4. The right vertebral artery began as the first branch of the subclavian artery. Its initial trajectory was rectilinear, followed by a right concave curve, a 360° loop that included a second ascending curve, and ended straight before entering the transverse foramen of C6. The coexistence of bilateral variations in the vertebral arteries is possible. This atypical situation can potentially generate vascular and neurological pathologies, but with different symptoms and causes. Knowing these variations and deliberately searching for them will enable the specialist to make a suitable differential diagnosis.

Existen múltiples reportes sobre variaciones anatómicas de las arterias vertebrales, las que se pueden relacionar con origen, trayecto, calibre y lateralidad. Sin embargo, las variaciones bilaterales son menos frecuentes, y menos común es que las variantes bilaterales sean diferentes entre ellas. El objetivo de este trabajo fue reportar la presencia de una variación bilateral de la arteria vertebral y su implicancia funcional y clínica. Disección en un cadáver de sexo femenino, fijado en formaldehido tamponado al 10 %, el cual no presentaba intervenciones quirúrgicas previas en la región de estudio y que tenía variaciones anatómicas en ambas arterias vertebrales. En cada una se realizó seguimiento desde su origen hasta su terminación, pudiendo determinar su trayecto, diámetros, ramificaciones y relaciones anatómicas. Se encontró una arteria vertebral izquierda originada en el arco aórtico, que realizaba un trayecto sinuoso de 4 curvaturas e ingresaba al foramen transverso de C4. La arteria vertebral derecha se originaba como primera rama de la arteria subclavia. Su trayecto inicial era rectilíneo seguido por una curva de concavidad derecha, un loop (giro) de 360° que incluía una segunda curva ascendente y terminaba en dirección recta antes de ingresar al foramen transverso de C6. La coexistencia de variaciones bilaterales en las arterias vertebrales es posible. Esta situación atípica, potencialmente puede generar en la persona patologías neurológicas de origen vascular, pero con sintomatología y causas diferentes. Conocer estas variaciones y realizar una búsqueda intencionada de ellas permitirá el especialista realizar un adecuado diagnóstico diferencial.

Arterial abnormalities and associated variations of the vertebrobasilar system on the brain base: apropos of a rare case / Anomalías arteriales y variaciones asociadas del sistema vertebrobasilar en la base del cerebro: un caso raro

SUMMARY: The presented case characterizes an association of primitive and definitive arteries with variations on the cadaveric brain base of a very old man. This case is found by the retrospective review of the data archive obtained during many years of cooperation of the author and co-authors. Fenestration of the (ectatic) basilar artery, partial and total duplication of some cerebellar arteries was associated with other variations of the vertebrobasilar and carotid systems. Although this is a case autopsied because of the myocardial infarction, the peculiarity of the case lies in the absence of the aneurysm based on the fenestration or dissection of one of the cerebral arteries.

RESUMEN: El caso presentado caracteriza una asociación de arterias primitivas y definitivas con variaciones sobre la base cerebral cadavérica de un anciano. Este caso se encuentra mediante la revisión retrospectiva de datos obtenidos durante muchos años de un trabajo de cooperación del autor y coautores. La fenestración de la arteria basilar (ectásica), la duplicación parcial y total de algunas arterias cerebelosas se asoció con otras variaciones de los sistemas vertebrobasilar y carotídeo. Si bien se trata de un caso de autopsia a causa de un infarto del miocardio, la peculiaridad del caso radica en la ausencia del aneurisma en base a la fenestración o disección de una de las arterias cerebrales.

Morphologic characterisation of the posterior inferior cerebellar artery. A direct anatomic study.

BACKGROUND: The number of studies on the cerebellar arteries has increased. The purpose of this study was to determine the morphological expression of posterior inferior cerebellar artery in a sample of Colombian population. MATERIALS AND METHODS: One hundred eighty-six posterior inferior cerebellar arteries of fresh cadavers were studied. In each specimen, vertebral arteries were injected with 100 mL of semi-synthetic resin, dyed with mineral red. RESULTS: In the 93 blocks of brainstem and cerebellum evaluated, 174 (93.5%) posterior inferior cerebellar arteries were found. Also, there were 12 (6.5%) ageneses. There was single posterior inferior cerebellar artery in 159 (91.4%) samples and duplicate in 10 (5.7%), while 5 (2.9%) specimens showed hypoplasia. The posterior inferior cerebellar artery originated from the vertebral artery in 121 (69.5%) samples and from the basilar artery in 42 (24.1%) samples; while in 11 (6.4%) it originated in a common trunk with the anterior inferior cerebellar artery. In 101 (83.5%) cases, the posterior inferior cerebellar artery originated from the intracranial segment of the vertebral artery, while 20 (16.5%) samples originated from the extracranial segment. The calibres of posterior inferior cerebellar artery in its proximal and distal segments were 1.45 ± 0.37 mm and 1.33 ± 0.31 mm, respectively. CONCLUSIONS: This study, carried out in cadaveric material, provides relevant qualitative and morphometric information of the posterior inferior cerebellar artery, useful for the diagnosis and clinical management, as well as for the surgical approaches that may compromise this structure.

Dual origin of vertebral artery and intimal relationship with spontaneous artery dissection: a case report and systematic review.

Dual origin of the vertebral artery (VA) is an uncommon anatomical variation. We describe a case of duplication origin at right vertebral artery (RVA) found incidentally in one elderly patient on investigation for cerebral aneurysm. Angiogram study showed a pseudoaneurysm at V4 segment of the RVA associated with embryological anatomy. The authors performed a systematic review of the similar cases reported worldwide.

Kommerell Diverticulum: Right Aortic Arch with Anomalous Origin of Left Subclavian Artery and Duplicity of Right Vertebral Artery in a 16-Year-Old Girl.

BACKGROUND Kommerell diverticulum with a right-sided aortic arch is a rare congenital anatomical condition most often observed in adults. A possible etiology of the subclavian artery's anomalous origin would be an abnormality in regression of the fourth primitive aortic arch during embryonic development. CASE REPORT We report on the case of a 16-year-old female patient presenting with complaints of occasional tachycardia and mild non-specific dyspnea after anxiety crises. Physical examination revealed lower amplitude of the pulses in the left upper limb compared to the right upper limb, and difference in blood pressure (BP) values of 80×60 mmHg, and 100×60 mmHg, respectively. Different radiological imaging modalities were performed to elucidate a possible vascular abnormality. Multislice detector computed tomography angiography of the thoracic aorta and supra-aortic trunks showed a right-sided aortic arch and an aberrant origin of the left subclavian artery with a retroesophageal course and dilation of its emergence (Kommerell diverticulum), as well as duplicity of the right vertebral artery (RVA). Considering the actual small diameter of the diverticulum and the absence of dysphagia or severe external esophageal compression analyzed by the esophagogram, vascular surgery was not indicated. Since complications have been described in the literature, the patient must be kept under observation in the future. CONCLUSIONS Congenital vascular alterations, including Kommerell diverticulum with right-sided aortic arch and the aberrant origin of the left subclavian artery, should be suspected in otherwise asymptomatic young patients with few clinical manifestations. Investigation with different imaging methods helps to clarify the vascular abnormalities, to support a possible surgical procedure indication, and to monitor the patients in follow-up.

Aberrant Origin of Vertebral Artery and its Clinical Implications.

Aberrant origin of vertebral artery is rare. The anatomical features and clinical significance of this lesion remain to be clarified. A comprehensive collection of the pertinent literature resulted in a cohort of 1286 cases involving 955 patients and 331 cadavers. There were more left than right and more unilateral than bilateral aberrant vertebral arteries. Patients with aberrant origin of vertebral artery were often asymptomatic and in only 5.5% of the patients their symptoms were probably related to the aberrant origin of vertebral artery. The acquired cardiovascular lesions were present in 9.5% of the patients, 20.9% of which were vertebral artery-associated lesions. Eight (0.8%) patients had a vertebral artery dissection. Logistic regression analysis showed significant regressions between bovine trunk and left vertebral artery (P=0.000), between the dual origins of vertebral artery and cerebral infarct/thrombus (P=0.041), between associated alternative congenital vascular variants and cervical/aortic dissection/atherosclerosis (P=0.008). Multiple logistic regression demonstrated that side of the aberrant origin of vertebral artery (left vertebral artery) (P=0.014), arch branch pattern (direct arch origin) (P=0.019), presence of the common trunk (P=0.019), associated acquired vascular disorder (P=0.034) and the patients who warranted management (P=0.000) were significant risk predictors for neurological sequelae. The patients with neurological symptoms and those for neck and chest operations/ interventions should be carefully screened for the possibility of an aberrant origin of vertebral artery. The results from the cadaver metrology study are very helpful in the design of the aortic stent. The arch branch pattern has to be taken into consideration before any maneuver in the local region so as to avoid unexpected events in relation to aberrant vertebral artery.

Aberrant Origin of Vertebral Artery and its Clinical Implications

Abstract Aberrant origin of vertebral artery is rare. The anatomical features and clinical significance of this lesion remain to be clarified. A comprehensive collection of the pertinent literature resulted in a cohort of 1286 cases involving 955 patients and 331 cadavers. There were more left than right and more unilateral than bilateral aberrant vertebral arteries. Patients with aberrant origin of vertebral artery were often asymptomatic and in only 5.5% of the patients their symptoms were probably related to the aberrant origin of vertebral artery. The acquired cardiovascular lesions were present in 9.5% of the patients, 20.9% of which were vertebral artery-associated lesions. Eight (0.8%) patients had a vertebral artery dissection. Logistic regression analysis showed significant regressions between bovine trunk and left vertebral artery (P=0.000), between the dual origins of vertebral artery and cerebral infarct/thrombus (P=0.041), between associated alternative congenital vascular variants and cervical/aortic dissection/atherosclerosis (P=0.008). Multiple logistic regression demonstrated that side of the aberrant origin of vertebral artery (left vertebral artery) (P=0.014), arch branch pattern (direct arch origin) (P=0.019), presence of the common trunk (P=0.019), associated acquired vascular disorder (P=0.034) and the patients who warranted management (P=0.000) were significant risk predictors for neurological sequelea. The patients with neurological symptoms and those for neck and chest operations/ interventions should be carefully screened for the possibility of an aberrant origin of vertebral artery. The results from the cadaver metrology study are very helpful in the design of the aortic stent. The arch branch pattern has to be taken into consideration before any maneuver in the local region so as to avoid unexpected events in relation to aberrant vertebral artery.

Type I persistent proatlantal artery associated with fusiform subclavian artery aneurysm: Report of one case.

We report a 61 years old male presenting with a right cerebral infarction, along with a type I persistent left proatlantal artery (PA), which is a form of primitive carotid-basilar anastomosis. The patient had an absence of the ipsilateral vertebral artery (VA) and hypoplasia of the contralateral VA, while the basilar artery was supplied by the PA. Other vascular anomalies present were a fusiform aneurysm of the right subclavian artery, and an A1 segment aplasia of the hypoplastic anterior right cerebral artery, which originated from the anterior communicating artery. To our knowledge these anomalies were not described previously.

Type I persistent proatlantal artery associated with fusiform subclavian artery aneurysm: Report of one case / Arteria proatlántica persistente tipo I asociada a un aneurisma fusiforme de la arteria subclavia: Presentación de un caso

We report a 61 years old male presenting with a right cerebral infarction, along with a type I persistent left proatlantal artery (PA), which is a form of primitive carotid-basilar anastomosis. The patient had an absence of the ipsilateral vertebral artery (VA) and hypoplasia of the contralateral VA, while the basilar artery was supplied by the PA. Other vascular anomalies present were a fusiform aneurysm of the right subclavian artery, and an A1 segment aplasia of the hypoplastic anterior right cerebral artery, which originated from the anterior communicating artery. To our knowledge these anomalies were not described previously.

Two cases of left vertebral artery emerging from a trunk in common with the left subclavian artery from the aortic arch / Dos casos de arteria vertebral izquierda naciendo de un tronco común con la arteria subclavia izquierda del cayado aórtico

Anomalies arising in the embryological development of the aortic arch and its branches are essencial in the emergence of variations in the origin and course of supra aortic vessels. Classically, 95 percent of cases, the aortic arch gives rise to the brachiocephalic artery, left common carotid artery and left subclavian artery. While the left vertebral artery arises normally from the left subclavian artery. In this presentation we describe two cases of the left vertebral artery being born of the aortic arch. The importance of anatomical knowledge of this arterial variety is fundamental for base neck and aortic arch surgery, in cervicothoracic trauma that compromises the vascular elements and in endovascular procedures in the region.

Anomalías desarrolladas en la evolución embriológica del arco aórtico y sus ramos son fundamentales en la aparición de variaciones en el origen y trayecto de los vasos supra aórticos. Clásicamente, en el 95 por ciento de los casos, el arco aórtico da nacimiento a las arterias braquiocefálica, carótida común izquierda y subclavia izquierda. Mientras que la arteria vertebral izquierda nace normalmente de la arteria subclavia izquierda. En este trabajo se exponen dos casos de la arteria vertebral izquierda naciendo del arco aórtico. La importancia del conocimiento anatómico de esta variedad arterial es trascendente para la cirugía de la base del cuello, cayado aórtico, en los traumatismos cervicotorácicos que comprometen los elementos vasculares y en procedimientos endovasculares de la región.

Síndrome do roubo da subclávia / Suclavian steal syndrome

A síndrome do roubo da subclávia refere-se a uma desordem vascular na qual ocorre inversão do fluxo de sangue da artéria vertebral ipsilateral, decorrente de uma estenose proximal à sua origem, geralmente uma oclusão da artéria subclávia ou, mais raramente, do tronco braquiocefálico. É uma doença relativamente rara, relatada em aproximadamente 6% dos pacientes assintomáticos com sopros cervicais. O Doppler pulsado (PW) é útil na análise da artéria vertebral, registrando informações capazes de identicar a presença da Síndrome do Roubo da Subclávia. Com base nas alterações hemodinâmicas da arteria vertebral avaliadas pelo estudo com Doppler Espectral, podem ser identificados três tipos de roubo da subclávia: oculto, parcial e completo. Com o advento da angioplastia transluminal percutânea e, em seguida, dos Stents, muitos advogam esta combinação de procedimentos como o tratamento de escolha dos casos sintomático desta síndrome.

MR angiography imaging of absence vertebral artery causing of pulsatile tinnitus: a case report / Imagen angiográfica a través de RM de la ausencia de arteria vertebral causante de tinitus pulsatil: reporte de caso

Absence of the vertebral artery is rare, and incidentally encountered in radiological imaging technics. We reported a 74 years old man suffering from pulsatile tinnitus with absence of the left vertebral artery. The purpose of the case report is the description absence of the vertebral artery causing of pulsatile tinnitus, in order to offer useful data to anatomists, otorhinolaryngologist, radiologists, vascular, head and neck surgeons.

La ausencia de la arteria vertebral es rara, y accidentalmente encuentrada en técnicas de imagen radiológica. Reportamos un hombre de 74 años que sufre de tinnitus pulsátil con la ausencia de la arteria vertebral izquierda. El propósito del reporte del caso es la descripción de la ausencia de arteria vertebral que causante del tinitus pulsátil, con el fin de ofrecer datos útiles para anatomistas, otorrinolaringólogos, radiólogos, cirujanos vasculares y de cabeza y cuello.

Arteria vertebral izquierda aberrante / Aberrant left vertebral artery

Se presenta una variación anatómica de la arteria vertebral izquierda, detectada en un cadáver utilizado para docencia en el Departamento de Anatomía de la Escuela de Medicina de la Pontificia Universidad Católica de Chile. En el mediastino superior del cadáver mencionado, se pudo apreciar que el arco aórtico da origen, de derecha a izquierda, a las siguientes ramas: arteria braquiocefálica, arteria carótida común izquierda, arteria vertebral izquierda aberrante y, finalmente, la arteria subclavia izquierda. La arteria vertebral izquierda aberrante se origina en la parte más alta del arco aórtico, presentando en este punto un diámetro de 4 mm; luego asciende a la izquierda de la carótida común ipsilateral y por sobre la cara anterolateral de la columna vertebral, tomando contacto con ramos cardíacos del tronco simpático cervical. Luego de un trayecto de 95 mm, ocupando el mediastino superior y la raíz del cuello, se hace profunda entrando en el foramen transverso de la 6 vértebra cervical, donde su calibre se ha reducido a 2,65 mm. En el presente trabajo, se discute la evolución que presentan las arterias intersegmentarias dorsales cervicales en la antímera izquierda que permite explicar esta variación anatómica.

An anatomical variation of the left vertebral artery, detected in a cadaver used for teaching purposes in the Department of Anatomy, School of Medicine, Catholic University of Chile is presented. In this case, the aortic arch gives rise, from right to left, to the following branches: the brachiocephalic artery, the left common carotid artery, the aberrant vertebral left artery and, finally, the left subclavian artery. The aberrant left vertebral artery originates from the top of the aortic arch, presenting here a diameter of 4 mm, then ascends to the left of the common carotid ipsilateral, over the anterolateral aspect of the spine, making contact with cardiac branches of the cervical sympathetic trunk. After ascending 95 mm, occupying the upper mediastinum and the root of the neck, the artery enters the transverse foramen of the 6th cervical vertebra, where its diameter was reduced to 2.65 mm. In this paper we discuss the development of the cervical dorsal intersegmental arteries in the left antimera, process that could explain this anatomical variation.

Neurovascular compression in painful tic convulsif.

This article describes the case of a 67-year-old woman who presented with a typical left hemifacial spasm of 8-month duration. After 2 months, she experienced lacinating and sharp shock-like pain in the left side of her face affecting the V1 and V2 territories and a discrete attenuation of nauseous reflex on the left side. CT angiography and MRI revealed significant compression of left cranial nerves V, VII, VIII, IX and X by a giant and tortuous vertebro-basilar arterial complex. This case illustrates the nonlinearity of the relationship between the presence of the stressor factor and the actual manifestation of the disease.

Fetal carotid-vertebrobasilar anastomoses: persistent hypoglossal artery associated with further variations of the circle of Willis.

During a routine dissection of the head and neck regions, a right persistent hypoglossal artery was found in a male individual who had died at approximately 40 years of age. This variation is associated with hypoplasia of the right and left vertebral arteries and absence of the right posterior communicating artery. Clinical implications of this variation are described. The article includes a review of the fetal carotid-vertebrobasilar anastomoses, their embryological explanation and associated pathologies.