Intraoperative identification of the lateral spinal artery in a case of craniocervical junction dural arteriovenous fistula surgically obliterated.

BACKGROUND: The formation of a dural arteriovenous fistula (DAVF) at the craniocervical junction is rare. Such a fistula can be fed by the branches of the vertebral and external carotid arteries. The lateral spinal artery can branch from the vertebral artery. The feeders of a DAVF at the craniocervical junction are often diagnosed on preoperative angiography, and there is little reported evidence on the intraoperative diagnosis of the lateral spinal artery. CASE DESCRIPTION: An 84-year-old man presented with motor weakness and sensory disturbance of the lower extremities. Edematous changes in the medulla oblongata and cervical spinal cord were observed on magnetic resonance imaging. Cerebral angiography revealed a DAVF fed by a branch of the vertebral artery, with a shunting point located in the dura of the right condyle; the main drain was the anterior spinal vein. The DAVF drain was surgically obliterated to prevent hemorrhagic events and improve neurological symptoms. Intraoperatively, an artery branching from the feeder of the DAVF was identified and preserved. The patient had a good postoperative course, and the neurological symptoms were ameliorated. Follow-up cerebral angiography revealed proximal branching of the lateral spinal artery from the feeding artery of the DAVF. CONCLUSION: A lateral spinal artery was identified intraoperatively while a DAVF at the craniocervical junction was obliterated. This suggests that preoperative imaging should be carefully reviewed, and endovascular procedures should consider such possibilities to avoid adverse ischemic outcomes.

The carotid and vertebral arteries discovery ­ initial findings / A descoberta das artérias carótidas e vertebrais ­ achados iniciais

The studies on the vascular system, including the cervicocephalic arteries (carotid and vertebral arteries), present a long trajectory, having their deep roots in the far past, considering the Western authors, having as representatives the Greek sages Alcmaeon, Diogenes, Hippocrates, Aristoteles, Rufus, and Galenus. They produced pivotal knowledge dissecting mainly cadavers of animals, and established solid bases for the later generations of scholars. The information assembled from these six authors makes it possible to build a quite clear picture of the vascular system, here specifically focused on the cervicocephalic arteries, and mainly of the extracranial segments. Thus, the carotid system became fairly well identified, origin, course, and name, as well as the origin of the still unnamed arteries running through the orifices of the transversal processes of the cervical vertebrae, and entering into the cranium. Almost all that was then known about human anatomy, since this period, and then throughout the Middle Ages, was extrapolated from animal dissections. This state of affairs was maintained until the 14th century, when human corpses dissections were again allowed.

Os estudos do sistema vascular, incluindo as artérias cervicocefálicas (artérias carótidas e vertebrais), apresentam um longo percurso, tendo suas raízes profundas no passado distante, considerando os autores ocidentais, tendo como representantes os doutos gregos Alcméon, Diógenes, Hipócrates, Aristóteles, Rufus e Galenus. Eles produziram conhecimento pivotal, dissecando principalmente cadáveres de animais e estabelecendo bases sólidas para as gerações futuras de estudiosos. A informação reunida desses seis autores permite construir um quadro bastante claro do sistema vascular, aqui focado especificamente nas artérias cervicocefálicas e principalmente nos seus segmentos extracranianos. Assim, o sistema carotídeo ficou bastante bem identificado, origem, trajeto e nome, assim como a origem das ainda não nomeadas artérias que percorrem os orifícios dos processos transversos das vértebras cervicais e entrando no crânio. Quase tudo que era conhecido sobre anatomia humana, desde esse período, e depois ao longo da Idade Média, foi extrapolado a partir de dissecções de animais. Esse estado de coisas foi mantido até o século 14, quando a dissecção de cadáveres humanos foi novamente permitida.

Bilateral vertebral arteries arising distal to the left subclavian artery: embryological and anatomical description.

Abnormalities in the origin of vertebral arteries are relatively uncommon, but extremely rare when this abnormality happens on both sides. We present an anatomic variation in which both vertebral arteries came from the proximal descending thoracic aorta beyond the left subclavian artery with no other supra-aortic vessels accompanying the abnormality. The right vertebral artery took a retro-oesophageal course (lusoria artery), while the right and the left vertebral arteries enter the transverse foramina at the 7th cervical vertebra. From an embryological point of view, and overall controversial, this anomaly can be explained by the bilateral persistence of the 8th intersegmental artery as the origin of vertebral artery, instead of the dorsal segment of the 7th intersegmental artery being the origin, which is normally the case. The adequate identification of vertebral artery anomalies in complementary explorations is very important to avoid misdiagnosed vertebral occlusions or unexpected vertebral artery injuries during supra-aortic trunks, thyroid, and oesophagus open surgeries, among others, or even over the course of endovascular procedures.

Side-to-Side Microvascular Anastomosis Using Rat Cervical Vessels.

BACKGROUND: Side-to-side anastomosis is the most challenging anastomosis owing to the difficult intraluminal suturing technique, which requires practice in the microsurgical laboratory before application in patients in the operating room. The objective of this study was to describe 2 side-to-side microvascular anastomosis training models using rat cervical vessels. METHODS: Two side-to-side microvascular anastomosis training models, one with rat cervical vessels between bilateral common carotid arteries (CCAs) (CCA-CCA anastomosis) and one with a unilateral CCA and the anterior facial vein of the external jugular vein (EJV) (CCA-EJV anastomosis), were studied. Diameters of CCA and anterior facial vein, distances between temporary clips and length of arteriotomies, and vascular clipping time were recorded. Patency rates were evaluated immediately and 7 days after the procedure. RESULTS: Diameters of CCA and anterior facial vein were 1.00-1.20 mm and 1.40-1.80 mm, respectively. A segment of vessel slightly longer than the arteriotomy or venotomy was temporarily clipped; mean lengths between temporary clips in CCA-CCA anastomosis and CCA-EJV anastomosis of 6.48 ± 0.66 mm and 8.02 ± 0.45 mm, respectively, were used in the study. The minimum distance between the corner of the arteriotomy or venotomy and the clip was 1 mm. The mean vascular temporary clipping times in CCA-CCA anastomosis and CCA-EJV anastomosis were 40.05 ± 3.92 minutes and 42.50 ± 4.82 minutes, respectively. Patency rates of 100% were achieved in all anastomoses. CONCLUSIONS: CCA-CCA and CCA-EJV side-to-side anastomosis models using rat cervical vessels are feasible and effective side-to-side anastomosis training models.

Assessing Vascular Function in Patients With Neck Pain, Headache, and/or Orofacial Pain: Part of the Job Description of All Physical Therapists.

SYNOPSIS: Vascular serious adverse events can occur after examining, manipulating, mobilizing, and prescribing exercise for the cervical spine. Patients presenting with neck pain and headache who develop a vascular serious adverse event during or after treatment may have vascular flow limitations that go unrecognized and are aggravated by treatment. Patients with neck pain and headache-the first nonischemic symptoms of arterial dissection-frequently access physical therapists as first-point providers, not all of whom have specialist training in orthopaedic manual physical therapy. All physical therapists, irrespective of their training, who are helping patients manage neck pain, headache, and/or facial symptoms must feel confident to identify potential vascular flow limitations of the neck prior to providing treatment. J Orthop Sports Phys Ther 2021;51(9):418-421. Epub 10 May 2021. doi:10.2519/jospt.2021.10408.

Ischemic Stroke in the Young.

The purpose of this article is to address several challenging questions in the management of young patients (those age 60 and under) who present with ischemic stroke. Do genetic thrombophilic states, strongly associated with venous thrombosis, independently cause arterial events in adults? Should cases of patent foramen ovale be closed with mechanical devices in patients with cryptogenic stroke? What are the optimal treatments for cerebral vein thrombosis, carotid artery dissection, and antiphospholipid syndrome and are DOACs acceptable treatment for these indications? What is the mechanism underlying large vessel stroke in patients with COVID-19? This is a narrative review. We searched PubMed and Embase and American College of physicians Journal club database for English language articles since 2000 looking mainly at randomized clinical trials, Meta analyses, Cochran reviews as well as some research articles viewed to be cutting edge regarding anticoagulation and cerebrovascular disease. Searches were done entering cerebral vein thrombosis, carotid dissection, anticoagulation therapy and stroke, antiphospholipid antibody and stroke, stroke in young adults, cryptogenic stroke and anticoagulation, patent foramen ovale and cryptogenic stroke, COVID-19 and stroke.

An anatomical investigation of the proximal vertebral arteries (V1, V2) in a select South African population.

INTRODUCTION: The most common type of vascular complication during cervical spine surgery is the vertebral artery (VA) injury. The presence of anatomical variation in the artery's morphology has been a significant factor for arterial injury during surgery. Therefore, physicians planning interventions in the craniospinal region need to be aware of the extents of variations. In addition to vascular injury, anatomical variations can predispose to some pathologies in the posterior circulation territory. To provide useful data to interventional radiologists, anatomists, and surgeons, we evaluated the anatomical features of the V1 and V2 segments of the VA in a South African population. MATERIALS AND METHODS: The study is an observational, retrospective chart review of 554 consecutive South African patients (Black, Indian and White) who had undergone computed tomography angiography (CTA) from January 2009 to September 2019. RESULTS: The VA exhibited morphological variation in its course. We report the incidence of variant origin of the left VA, all from the aortic arch. Variation in the level of entry into the transverse foramen ranged between C7 and C3. A left dominant pattern was observed; we also report on hypoplasia of the VA. In addition, we report incidence of VA tortuosity at V1, V2 to be 76.6% and 32.1%, respectively. CONCLUSIONS: The baseline data established in this study regarding the diameter, variant origin, and level of entry into the transverse foramen will assist neurosurgeons and interventional radiologists in interpreting, diagnosing, and planning and executing various vascular procedures and treatment of pathology in the vicinity of the VA.

A quantitative analysis of the dimensions and content of the vertebral triangle.

PURPOSE: The vertebral triangle (VT) located in the root of the neck most commonly contains the vertebral artery (VA), cervical sympathetic chain and certain roots of the brachial plexus. Although other structures have been reported, few studies have reported on the overall content of this space. Based on the current literature, there is a general paucity of anatomical information pertaining to the dimensional anatomy of the VT and specifically the structures related to it. Therefore, this study aimed to quantitatively analyze the size, position, content, and anatomical structures in relation to the vertebral triangle in a South African sample. METHODS: Forty-three VTs were dissected on bodies donated to science. Measurements taken include the dimensions of the triangle, as well as distances between prominent structures and landmarks of the VT. Observations were made on the presence/absence of the varying neurovascular structures within the VT. RESULTS: Mean height was 30.1 ± 1.51 mm (R) and 32.9 ± 1.78 mm (L). Mean width was 18.3 ± 0.74 mm (R) and 19.3 ± 0.98 mm (L). The C8 spinal nerve was found on average approximately halfway [16.4 ± 0.74 mm (R) and 15.9 ± 0.95 mm (L)] in the VT. The VA was present in the VT in 100% of the sample and the C7 spinal nerve and inferior sympathetic ganglia were present in more than 80% of the sample. CONCLUSION: Understanding the VT and the content is of the utmost importance and of great interest to neurosurgeons, to avoid these important neurovascular structures and prevent iatrogenic complications during surgery.

Right vertebral artery entering the third transverse foramen diagnosed by magnetic resonance angiography: a report of two cases.

The vertebral artery (VA) usually enters the sixth transverse foramen (TF). The VA sometimes enters the fifth, and rarely enters the fourth or seventh TF. Reports describing a VA entering the third TF, identified by anatomical dissection or computed tomography angiography, are extremely rare. We herein report two cases in which magnetic resonance (MR) angiography showed the right VA entering the third TF. Coronal reformatted MR angiography source images were useful for identifying the level at which the VA entered the TF. Because the anomalous VA takes an anterior course, it poses a risk during anterior neck surgery. Thus, a correct diagnosis is important when interpreting cervical MR angiography.

Spinal anastomosed remnant imprints of vertebral veins linking the transverse foramina: a case report of a novel anatomic variant of the cervical venous plexus.

PURPOSE: Despite various postulated classifications attempting to simplify the complex angioarchitecture of the cervical spine, the nomenclature of spinal variants and lesions remains inconsistent. Knowledge of variations in the anatomy of the vertebral veins will assist in avoiding complications during neck surgery and procedures such as vertebroplasty. In addition, venous variants may act as a route for the spread of infection, emboli, or metastases. Therefore, we report a novel variant encountered at our institution in this case report. METHODS: We coincidentally discovered an original anatomical variant of the cervical venous plexus linking the transverse foramina in a Saudi man. RESULTS: We termed the variant "spinal anastomosed remnant imprints" (SARI), guided by the second edition of Terminologia Embryologica, a project of the Federative International Programme for Anatomical Terminology. This variant anastomoses with the vertebral veins at the same level, forming segmented osseous impressions. It shares a topographical relationship with the embryonic anterior cardinal veins, which normally regress in the prenatal period. We hypothesize that these intersegmental anastomosing veins do not always regress and may persist into adulthood, with individualized variations of the venous circulation. CONCLUSION: This report highlights an important finding of interpersonal anatomical variation of veins in the cervical spine, discovered with the aid of advanced imaging to distinguish it from pathological conditions. This will be of assistance to radiologists, anatomists, and clinicians in decision-making and to surgeons in planning for neck surgery.

Computed tomographic angiography to analyze dangerous vertebral artery anomalies at the craniovertebral junction in patients with basilar invagination.

OBJECTIVE: Failure to detect dangerous anatomic vertebral artery anomalies (AVAAs) and dangerous functional vertebral artery anomalies (FVAAs) at the craniovertebral junction (CVJ) in patients with basilar invagination (BI) can result in major complications such as intraoperative vertebral artery injury, brain infarctions, and even death. Iatrogenic vertebral artery injury is a rare but severe complication of cervical spine surgery. We aimed to evaluate dangerous vertebral artery anomalies at the CVJ in patients with BI using computed tomographic angiography (CTA). METHODS: CTA images of 61 BI patients were retrospectively analyzed to evaluate AVAAs and FVAAs at the CVJ. Dangerous AVAAs include a persistent first intersegmental artery (FIA), fenestration of the vertebral artery (FEN), and posterior inferior cerebellar artery with an extradural C1/2 origin (PICA-C1/2). Dangerous FVAAs include a dominant vertebral artery (DVA) and hypoplastic vertebral artery ending in the PICA (HVA-PICA) without joining the basilar artery. RESULTS: Overall, 31 female and 30 male patients (mean age, 42.3 years) were included. The incidences of FIA, FEN, and PICA-C1/2 were 29.5 % (18/61), 3.3 % (2/61), and 3.3 % (2/61), respectively, whereas the incidences of DVA and HVA-PICA were 36.1 % (22/61) and 1.65 % (1/61), respectively. CONCLUSION: Dangerous vertebral artery anomalies at the CVJ have a high incidence in patients with BI. Preoperative CTA is highly recommended in such patients to identify anomalous vertebral arteries and reduce the risk of intraoperative injury.

Cervical Carotid Artery Dolichoectasia as a Marker of Increased Vascular Risk.

Cervical carotid artery (cCA) dolichoectasia (DE) is characterized by elongation, tortuosity, and/or dilatation. The prevalence of cCA DE has been reported 13-31% in population-based and 14-58% in hospital-based studies. The exact mechanisms of this aberrant arterial remodeling are unknown. Although atherosclerosis has often been implicated, the evidence has conflicting results that would support atherosclerosis as the underlying pathology. Actually, other nonatherosclerotic mechanisms related to connective tissue remodeling may play a role. Such mechanism is supported by epidemiological evidence that cCA DE is associated with carotid dissections. Similarly, cCA DE has been associated with vascular risk factors, but inconsistently. Fewer studies have evaluated the risk of vascular events in people with cCA DE. Cross-sectionally, cCA DE is associated with cerebrovascular disease, including white matter hyperintensities, lacunar stroke, and stroke overall. The often-conflicting results may in part be due to the heterogeneity of the population studies and variable definitions used. Preferential use of objective measure of cCA DE, such as carotid length, is advisable, and may help comparing result among different studies. Prospectively, people with cCA DE have a higher risk of vascular events, although it is uncertain if the risk of stroke is also higher in this population. In the absence of alternative stroke etiologies, stroke patients with cCA DE should be considered to have had a cryptogenic stroke and treated with daily antiplatelet therapy. Further population-based studies are needed to clarify whether specific therapies may be implement to reduce the risk of events among people with cCA DE.

Prevalence of High-Riding Vertebral Artery: A Meta-Analysis of the Anatomical Variant Affecting Choice of Craniocervical Fusion Method and Its Outcome.

OBJECTIVE: A high-riding vertebral artery (HRVA) has been defined as a C2 isthmus height of ≤5 mm and/or internal height of ≤2 mm measured 3 mm lateral to the border of the spinal canal. Its reported prevalence has varied widely. If overlooked during the approach for craniocervical fusion, injury to the vertebral arteries can occur, affecting the outcome. The present meta-analysis aimed to provide the pooled prevalence of HRVAs. METHODS: A comprehensive database search was conducted by 3 of us. Peer-reviewed studies that had followed the strict definition for HRVAs and had reported its prevalence were included. The risk of bias was assessed using the anatomical quality assessment tool. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. The pooled prevalence was calculated using a random effects model. RESULTS: The data from 20 studies with 3126 subjects (7496 sides) were analyzed. The overall pooled prevalence of ≥1 HRVA was 25.3% (95% confidence interval [CI], 19.6%-31.5%). The prevalence in those without the most important confounding factor, rheumatoid arthritis (RA), was 20.9% (95% CI, 16.5%-25.8%). Patients with RA had a prevalence of 42.9% (95% CI, 23.8%-63.1%). The difference between the non-RA and RA groups was statistically significant (P < 0.001, test of homogeneity, χ2). No geographical differences were noted (P = 0.20, test of homogeneity, χ2). Among those with HRVA, unilateral HRVA was present in 70.3% (95% CI, 65.2%-75.2%) and bilateral in 29.7% (95% CI, 24.8%-34.8%). No left or right side predilection was found (left, 50.8%; 95% CI, 33.8%-67.6%; right, 49.2%; 95% CI, 32.4%-66.2%). CONCLUSIONS: Craniocervical fusion should be preceded by examination of the vertebral arteries at the level of C2 because the presence of HRVAs is common and might preclude the safe insertion of transarticular or transpedicular screws.

Changes in Vertebral Arterial Blood Flow During Premanipulative Tests in Participants With Upper Cervical Spine Motion Restriction.

OBJECTIVE: The purpose of the present study was to measure changes in blood flow velocity and volume flow rate (VFR) in the contralateral vertebral artery (VA) during end-range rotation and pre-manipulative hold at C1-C2 and to compare these measurements between participants with and without C1-C2 range of motion (ROM) restriction. METHODS: This research was approached as an exploratory study and designed as a parallel noninterventional controlled trial with intentionally equal allocation, for studying diagnostic tests. Fifteen women and 13 men (mean age 44) were recruited (volunteer sample) in physiotherapy clinics. No participant had any current neurologic or vertebrobasilar insufficiency symptoms. The measurements of 13 participants with a limited ROM C1-C2 and 15 with no limitation were compared. Blood flow velocity and VFR in the contralateral VA were measured using color duplex Doppler imaging in 3 neck positions: neutral, maximal rotation, and pre-manipulative hold of C1-C2. RESULTS: Pre-manipulative hold significantly (P < .01) decreased all blood flow velocity parameters and VFR, mainly in the left VA. End-range rotation showed a significant (P < .05) decrease in the peak systolic velocity in the left VA. No significant differences were found between participants grouped by the presence or absence of a C1-C2 ROM restriction. CONCLUSION: A C1-C2 rotational ROM restriction does not appear associated with change in a significantly reduced VA blood flow due to the neck position.

Occipital artery arising from the cervical internal carotid artery at the level of the C2 vertebral body: three cases detected utilizing magnetic resonance angiography.

We incidentally observed the occipital artery (OA) arising from the cervical internal carotid artery (ICA) at the level of the C2 vertebral body on magnetic resonance (MR) angiography in three patients. In the rare case in which the OA arises from the ICA, it is generally at its origin. The OA arises from the cervical ICA when all but the distal part of the anastomosis of the primitive proatlantal artery between the ICA and vertebral artery persists. Careful review of MR angiographic images is important to detect rare arterial variations, and both partial maximum-intensity-projection images and source images aid their identification on MR angiography.

Is the Vertebral Posterior Line a Safety Landmark for Cervical Posterior Screw Insertion? - Radiological Study of the Vertebral Artery in the Cervical Spine.

At posterior cervical fixation, iatrogenic injury of the vertebral artery (VA) must be avoided. As the VA is usually located in front of the posterior line of the vertebral body, intraoperative lateral fluoroscopy is used to identify the line. We investigated in how many of 105 patients (210 VAs) this line is a safe marker. We also inspected the original cervical magnetic resonance angiograms (MRA) of 105 consecutive patients who had been treated for other than cervical spine diseases to study some anatomical characteristics of the VA in the cervical spine. The distance from the posterior line of the vertebral body to the posterior VA surface was classified as safe, as requiring attention, and as unsafe. Among the 210 VAs, four hypoplastic vessels were excluded from this study; consequently, 206 VAs were available for assessment. The average distance exceeded 6 mm, it was shorter at the upper cervical level. Although in at least 200 VAs (97.1%) the distance between C4 and C7 was safe, in only 170 VAs (82.5%) was it safe at C3. We observed a total of 31 tortuous loops in 17 VAs; their presence had a significant negative effect on the usefulness of the safety line. Although the posterior line of the vertebral body may be useful for safe screw insertion at the C4-C7 level, it may be less useful at C3. In the presence of tortuous VA loops, close attention must be paid to the reliability of the safety line during cervical spine surgery.

Differences in distribution of anterior segmental medullary arteries in the cervical and thoracolumbar spinal cord: the "inseln" were characteristics in the cervical spinal cord.

Anterior segmental medullary arteries cause spinal cord infarction due to circulatory disturbance, but are difficult to identify in diagnostic images. This study investigated the arterial distribution from the cervical to lumbar segments of the dissecting spinal cord in 100 cadavers. The 488 arteries were distributed from C2 to L2, of which 252 arteries from C2 to C8 were slightly dominant on the right side, but 236 arteries from Th1 to L2 were obviously dominant on the left side. This change occurred at the C8 and Th1 segments. Of the 252 arteries, 37.30% (94 arteries) were divided into ascending and descending branches. Both branches formed loops by anastomosis with the anterior spinal arteries. The loops, called "insel", have an unclear distribution and form. We focused on the features of inseln and found 63 of them in the cervical spinal cord of 45 cadavers. Their numbers and forms differed depending on whether the 94 arteries were bilateral (type A) or unilateral (type B), but the long axis of the insel was limited to one cervical segment. 90.63% of type A were bilateral at the same level, and 70% of type B were on the right side. The former always formed the insel. Further, 94 arteries were distributed from C2 to C7, 82.98% of which were concentrated at C3-C5. Therefore, the arterial blood supply of the spinal cord may differ between the cervical spinal cord and the thoracolumbar cord.