Variations of transverse foramina in cervical vertebrae: what happens to the vertebral artery?

A Case With Twists and Turns: A Report of Vertebrobasilar Dolichoectasia

Vertebrobasilar dolichoectasia (VBD) is a rare anatomical abnormality of the vertebral artery system, defined as irregular expansion, elongation, and tortuosity of vertebral arteries. Anomalies of the vertebrobasilar artery can have a wide variety of clinical presentations, ranging from simple headaches to debilitating strokes. We present the case of an atypical presentation of VBD which mimicked trigeminal neuralgia by compressing the trigeminal nerve. There are currently no guidelines concerning the management of VBD, nor is there evidence of a definitive cure. This case invoked discussions among the medical team as to whether management should be medically or surgically focused, as well as long-term outcomes for patients with VBD. The superiority of medical versus surgical treatment of this issue is still a debated topic. This patient trialed medical management with dexamethasone and carbamazepine with no improvement in symptoms. He then underwent surgical gamma knife treatment but even this invasive measure was unsuccessful at relieving his symptoms. We hope that by presenting this case, we can display how the therapies available for VBD are limited and often unsuccessful in relieving the disease burden in patients with VBD.

Historic Horse Family Displaying Malformations of the Cervicothoracic Junction and Their Connection to Modern German Warmblood Horses

Malformations of the equine cervicothoracic junction affect the C6 and C7 cervical vertebrae, the T1 thoracic vertebra and in variable extent the first and second sternal ribs. To date, the clinical impact of this malformation, its prevalence and mode of inheritance in equine populations are not yet determined. We examined five skeletons for signs of malformation of the cervicothoracic junction, including three skeletons from widely used Thoroughbred stallions affected with the malformation and two skeletons serving as a comparison. The three affected historical horses were the Thoroughbred stallions Der Loewe XX, Birkhahn XX and their common great grandsire Dark Ronald XX. Malformations of C6 and C7 showed a large variation between the three stallions, as Dark Ronald XX, Der Loewe XX and Birkhahn XX were affected uni-laterally at C6 and C7, uni-laterally at C6 and bi-laterally at C6 and C7, respectively, with varying grades. In order to evaluate whether or not these malformations are incidental, we took a random sample of 20 living German Warmblood horses, which are distant descendants of these stallions. This sample consisted of ten controls and ten horses with malformations of C6/C7. Blood proportions of the historical sires in the modern Warmblood horses ranged from 0.10 to 6.25%. The contribution to inbreeding in each individual horse of our selected horse group by those sires was expressed as a percentage of the total inbreeding coefficient and ranged from 0.01 to 17.96%, demonstrating their influence on the modern Warmblood. In the present study, we were able to describe the variability of the malformation of C6/C7 within a horse family including historic and modern horses. Additionally, we detected variations appearing in connection with malformations of the cervicothoracic junction that have not been described in the literature yet. This is the first time that the malformations of C6 and C7 have been described within a familial context, providing hints on inheritance in Thoroughbreds and Warmbloods. It is worthwhile to carry out further studies in a larger setting to gain more comprehensive insights into the inheritance of the malformation and the role of important ancestors.

An Unusual Origin of the Left Vertebral Artery: A Case Report

The present paper describes a 53-year-old male who presented to the emergency department with a history of sudden chest pain followed by unconsciousness at home. The autopsy revealed the left vertebral artery (LVA)'s aberrant origin from the aortic arch between the left common carotid artery and subclavian artery in a male deceased during a medicolegal autopsy. The aortic origin of the vertebral artery is an unusual branching pattern. Knowledge about the vertebral artery's normal and variant arterial anatomy is essential for patients who undergo various surgical or interventional procedures. In the sudden death of cardiac origin, its anatomy and morphology also hold crucial value. Typically, the LVA arises from the first part of the left subclavian artery (LSA).

Investigation of accessory transverse foramen in dry cervical vertebrae: incidence, variations, types, locations, and diagnostic implications

Background

This research aimed to determine the incidence, variations, types, and potential locations of the accessory transverse foramen (ATF) in dry cervical vertebrae. A total of 250 Turkish dry cervical vertebrae were examined, with 500 transverse foramina investigated. The cervical vertebrae were categorized into five groups (C3–C7), and each cervical vertebra was assessed bilaterally to determine the location, incidence, and side of the ATF.

Results

ATF was observed in 21 vertebrae (8.4%) and was distributed posteriorly (76.2%), posterolaterally (19.04%), and posteromedially (4.8%) in relation to the location of the TF. The incidence of ATF was 4.8% in C3, 28.6% in C4, 9.5% in C5, 23.8% in C6, and 33.3% in C7. Furthermore, a statistically significant difference was observed in the unilateral or bilateral occurrence of the ATF (F = 3.079; p = 0.047, p < 0.05).

Conclusions

In this study, we have presented an investigative approach and discussed the potential implications of identifying the ATF in dry cervical vertebrae. The presence of ATF can be crucial in the diagnosis of variations in the vertebral artery (VA) and underlying disorders, potentially aiding in the determination of the cause of death or ancestry. Additionally, the posterior location of the ATF and its asymmetric distribution should be taken into account when evaluating dry cervical vertebrae, which may offer valuable information for the identification of variations.

Investigation of accessory transverse foramen in dry cervical vertebrae: incidence, variations, types, locations, and diagnostic implications

Background

This research aimed to determine the incidence, variations, types, and potential locations of the accessory transverse foramen (ATF) in dry cervical vertebrae. A total of 250 Turkish dry cervical vertebrae were examined, with 500 transverse foramina investigated. The cervical vertebrae were categorized into five groups (C3–C7), and each cervical vertebra was assessed bilaterally to determine the location, incidence, and side of the ATF.

Results

ATF was observed in 21 vertebrae (8.4%) and was distributed posteriorly (76.2%), posterolaterally (19.04%), and posteromedially (4.8%) in relation to the location of the TF. The incidence of ATF was 4.8% in C3, 28.6% in C4, 9.5% in C5, 23.8% in C6, and 33.3% in C7. Furthermore, a statistically significant difference was observed in the unilateral or bilateral occurrence of the ATF (F = 3.079; p = 0.047, p < 0.05).

Conclusions

In this study, we have presented an investigative approach and discussed the potential implications of identifying the ATF in dry cervical vertebrae. The presence of ATF can be crucial in the diagnosis of variations in the vertebral artery (VA) and underlying disorders, potentially aiding in the determination of the cause of death or ancestry. Additionally, the posterior location of the ATF and its asymmetric distribution should be taken into account when evaluating dry cervical vertebrae, which may offer valuable information for the identification of variations.

A Rare Case Report of a Vertebral Artery Variant Arising From the Aorta With Its Clinical Significance: An Uncommon Anatomy Unveiled

The vertebrobasilar (VB) system, comprising two vertebral arteries and one basilar artery, is responsible for providing vital vascular supply to the central nervous system structures. Disruption in this network can lead to fatal neurologic outcomes, and variations in the origin of vessels may contribute to unexplained symptoms of clinical relevance. Therefore, an extensive understanding of the VB system's anatomy and its variations is crucial for diagnosing neurological disorders. Here, we report a case of a vertebral artery variant arising from the aortic arch proximal to the left subclavian artery in the cadaver of a 50-year-old male, discovered incidentally during a teaching dissection session. We also discuss the clinical pathophysiology and the relevance of the neurological symptoms in relation to the anomaly.

Anatomical variations of human vertebral and basilar arteries: A current review of the literature

The vertebral artery originates from the subclavian artery and is divided into four segments (V1-V4). In its intracranial segment (V4), the two vertebral arteries join to form the basilar artery, an unpaired medium-sized artery. However, apart from this typical description, several anatomical variations may occur in the human body. Although in some cases such variations may be asymptomatic, they may be also associated with several pathological conditions, neurological complications, surgical complications, and increased risk of developing vascular diseases. Therefore, it is crucial to obtain sufficient information on the anatomy and variants of both arteries to prevent such complications and ensure the safe completion of surgical and radiological treatments. For this reason, we reviewed studies published up to January 2022 concerning the reported variations of the vertebral artery and basilar artery regarding their origin, course, length, and diameter. We believe that the thorough presentation of these variations would help surgeons worldwide during their daily clinical and surgical practice.

Spinal Injections

Spinal pain is a common complaint and cause of disability in the United States, affecting most individuals at some point in their lives. The complex anatomy of the spine leads to multiple potential and coexisting etiologies for pain, and the differentiation of these sources can present a diagnostic challenge. Image-guided spinal injections can provide both diagnostic information identifying pain location as well as prolonged therapeutic relief as an alternative to medical management. Anesthetic and corticosteroid medications can be administered within the epidural space through transforaminal or interlaminar approaches, blocking various sensory nerves, or directly within the facet joints. Proceduralists must be aware of associated patient considerations, techniques, and potential complications to perform the procedures safely. We discuss image-guided spinal injection techniques, based on best practices and our experiences.

An association between vertebral artery dominance and steno-occlusion of the vertebral artery segments: A retrospective angiographic study

OBJECTIVES

This study investigated whether there was a relationship between steno-occlusion of the vertebral artery (VA) segments and the dominant VA side.

MATERIALS AND METHODS

Angiography results of 215 patients (146 men; 69 women) were retrospectively analyzed in this study. The patients were divided into three groups: dominant, non-dominant and co-dominant. These groups were compared according to the presence of steno-occlusion in the vertebral artery segments. The results were evaluatedusing X², Mann-Whitney U and Kruskal-Wallis tests. For correlation analysis, Spearman's Rho test was used.

RESULTS

The findings showed that 55 of 215 patients (25.6%) had a right dominant VA, and 103 (47.9%) had left dominant VA. There was no significant relationship between dominance and age or gender (p > 0.05). More vertebral artery stenosis (VAS) was found on the dominant side. However, a significant relationship only in the right dominant V1 segment (p = 0.044) was noticed. Hypoplastic VA was detected in 13 patients (6%). Most of the VAs (98.4%, n = 423) arose from the subclavian artery.

CONCLUSIONS

In conclusion, we found more vertebral artery stenosis on the dominant side than the co-dominant side, especially on the origin of the vertebral arteries. However, it was only significant on the right dominant V1 segment, regardless of age and gender of the patients (p > 0.05).

Anatomical Variations of the Vertebral Artery: Analysis by Three-Dimensional Computed Tomography Angiography in Chinese Population

OBJECTIVE

To analyze the anatomical variations of V3 and V2 segments of the vertebral artery in the Chinese population.

METHODS

The current retrospective study was an observational, anatomical, radiological research. Between 1 January 2018 to 31 December 2019, the data of 589 continuous head-and-neck three-dimensional computed tomography angiography were observed and analyzed using the open-source software of Horos. There were 415 males and 174 females with an average age of 44.63 ± 2.5(18-74) years. The variations of the V3 segment were defined as persistent first intersegmental artery (PFIA) and paracondylar processes (PP). The variations of V2 segments were unusual vertebral artery entrance transverse foreman (UE-V2S) and midline migration (MM). The incidences of all variations were summarized and the gender, side characters were compared.

RESULTS

Among the patients, 4.34% (18/415) males and 4.60% (8/174) females were with the variation of PFIA. Meanwhile, 12.29% (51/415) males and 10.92% (19/174) females were with the variation of PP. Then 18.80% (78/415) males and 16.67% (29/174) females were with UE-V2S. All the variations above were not different in genders. As for the variation of MM, 3.86% (16/415) males and 8.62% (15/174) females were identified, and the difference of genders was significant for this type of variation (P < 0.05). The differences between each side were also observed and analyzed for all variations and no differences were found.

CONCLUSION

There are several variations of V3 and V2 segments of the vertebral artery are associated with the cervical surgeries, most were without differences in genders and sides, except the variation of MM.

Evaluation of tortuous vertebral arteries before cervical spine surgery: illustrative case

BACKGROUND

Cervical spine surgery sometimes necessitates complex ventral/dorsal approaches or osteotomies that place the vertebral artery (VA) at risk of inadvertent injury. Tortuosity of the VA poses increased risk of vessel injury during anterior decompression or placement of posterior instrumentation.

OBSERVATIONS

In this report, the authors describe a patient with degenerative cervical spondylotic myelopathy and focal kyphotic deformity requiring corrective surgery via a combined ventral/dorsal approach. Computed tomography (CT) and CT angiography (CTA) of the spine identified a left medially enlarged C4 transverse foramen and tortuous VA V2 segment forming a potentially dangerous medial loop into the vertebral body, respectively. The patient’s presentation and management are described.

LESSONS

The course of the VA is variable, and a tortuous VA with significant medial or lateral displacement may be dangerous during ventral and dorsal approaches to the cervical spine. CTA of the cervical spine is warranted in cases in which atlantoaxial fixation is needed or suspicious transverse foramen morphology is identified to understand the course of the VA and identify anatomical variations that would put the VA at risk during cervical spine surgery.

Accessory Vertebral Artery: An Embryological Review With Translation from Adachi

The vertebral arteries arise from the posterior superior aspect of the bilateral subclavian arteries and course superiorly through the transverse foramina of C1-C6 vertebrae before joining one another along the anterior surface of the pons. Developmental variations during the fourth to sixth weeks of embryonic development may result in the formation of accessory vertebral arteries, i.e., ipsilateral vertebral arteries of dual origin. This anatomical variation is distinct from and often confused with vertebral artery duplications and fenestrations. This article reviews the anatomy and embryology of the accessory vertebral artery with excerpts from Buntaro Adachi's classic text on vascular anatomical variations. Knowledge of accessory vertebral vessels is important during vascular and spinal procedures of the head and neck. Furthermore, these variations have been associated with cerebrovascular pathologies, such as stroke, dissection, and other hemodynamic anomalies.

A Novel and Reproducible Classification of the Vertebral Artery in the Subaxial Cervical Spine

BACKGROUND

An injury of the vertebral artery (VA) is one of the most catastrophic complications in the setting of cervical spine surgery. Anatomic variations of the VA can increase the risk of iatrogenic lacerations.

OBJECTIVE

To propose a novel and reproducible classification system that describes the position of the VA based on a 2-dimensional map on computed tomography angiographs (CTA).

METHODS

This cross-sectional retrospective study reviewed 248 consecutive CTAs of the cervical spine at a single academic institution between 2007 and 2018. The classification consists of a number that characterizes the location of the VA from the medio-lateral (ML) aspect of the vertebral body. In addition, a letter describes the VA location from the anterior-posterior (AP) aspect. The reliability and reproducibility were assessed by 2 independent raters on 200 VAs.

RESULTS

The inter- and intrarater reliability values showed the classification's reproducibility. The inter-rater reliability weighted κ-value for the ML aspect was 0.93 (95% CI: 0.93-0.93). The unweighted κ-value was 0.93 (95% CI: 0.86-1.00) for "at-risk" positions (ML grade ≥1), and 0.87 (95% CI: 0.75-1.00) for "high-risk" positions (ML grade ≥2). The weighted κ-value for the intrarater reliability was 0.94 (95% CI: 0.95-0.95). The unweighted κ-values for the intrarater reliability were 0.95 (95% CI: 0.91-0.99) for "at-risk" positions, and 0.87 (95% CI: 0.78-0.96) for "high-risk" positions.

CONCLUSION

The proposed classification is reliable, reproducible, and independent of individual anatomic size variations. The use of this novel grading system could improve the understanding and interdisciplinary communication about VA anomalies.

Traumatic vertebral artery injury: a review of the screening criteria, imaging spectrum, mimics, and pitfalls

PURPOSE

Traumatic vertebral artery injury (TVAI) can have a varied clinical presentation and appearance on imaging. In this review, we present the screening criteria, spectrum of imaging features, grading, and imaging pitfalls of TVAI. Our review focuses on the imaging of TVAI on computed tomography angiography (CTA), magnetic resonance angiography (MRA), and cases of TVAI mimics.

IMAGING

The imaging spectrum on CTA can range from either focal or long segment luminal stenosis (the most common findings), smooth or tapered narrowing of lumen, string of pearls appearance, concentric intramural haematoma, intimal flap (the most definite sign), and double lumen of the artery. On time-of-flight MRA, the most common findings include loss of flow void within the vessel due to slow flow, thrombosis or occlusion, and hyperintense signal within the vessel wall due to intramural haematoma on T1 fat-saturated images.

CONCLUSION

The reader should be aware of the screening criteria, common and uncommon findings, variant anatomy, artifacts, and mimics of TVAI when evaluating cases of craniocervical trauma, to be competent in calling in or ruling out injury.

Prevalence of anatomic variations of the atlas vertebra

BACKGROUND CONTEXT

The retrotransverse foramen (RTF), arcuate foramen (AF), unclosed transverse foramen (UTF) and posterior atlas arch defects (PAAD) are anatomic variations of the atlas vertebra that surgeons must be aware of before spine surgery is performed.

PURPOSE

To analyze the prevalence of the AF, RTF, UTF, and PAAD.

STUDY DESIGN

Ex-vivo anatomical study.

PATIENT SAMPLE

Two hundred eighteen atlas vertebrae obtained from 100 Caucasian subjects and 118 sub-Saharan African subjects (48 Sotho subjects, 35 Xhosa subjects and 35 Zulu subjects).

METHODS

We studied 218 atlas vertebrae from skeletons of the Raymond A. Dart Collection in order to analyze the prevalence of AF, RTF, UTF, and PAAD in both Caucasian and sub-Saharan African subjects.

OUTCOME MEASURES

Not applicable.

RESULTS

Sixty-nine (31.2%) atlases presented anatomical variants: 64 (29.3%) presented one anatomical variant, 4 (1.8%) presented two, and 1 (0.5%) presented three. AF, RTF, UTF, Type A and Type E defects were present in 35 (16.1%), 17 (7.8%), 17 (7.8%), 5 (2.3%), and 1 (0.5%) vertebrae, respectively. The vertebrae with two anatomical variants presented a bilateral UTF and a Type A defect, a bilateral AF and a Type A defect, a right UTF and a left AF, and a right UTF and a Type E defect. The vertebra with three anatomical variants presented a bilateral RTF, a left UTF, and a left AF. No sex differences in prevalence of the RTF (p=.775), AF (p=.605), UTF (p=.408) and Type A defects (p=1.000) were found in the sub-Saharan African and Caucasian groups (RTF, p=.306; AF, p=.346; UTF, p=.121; Type A defects, p=.561). Comparison between the sub-Saharan African (all subjects) and the Caucasian group revealed no differences in the UTF (p=.105), AF (p=.144), RTF (p=.542) and Type A defects (p=.521) prevalence. Also, no differences in the prevalence of the UTF (p=.515), AF (p=.278), and RTF (p=.857) between Zulu, Xhosa and Sotho subjects were found. Neither were found sex differences in the prevalence of UTF, RTF and AF in Zulu (p=.805, p=.234, p=.129), Xhosa (p=.269, p=.181, p=.309), and Sotho subjects (p=.062, p=.590, p=.106).

CONCLUSIONS

The present study has revealed no sex differences in the prevalence of AF, UTF, RTF or PAAD in both Caucasian and sub-Saharan African subjects. This research has also indicated no differences in the prevalence of the UTF, AF and RTF between Zulu, Xhosa and Sotho subjects. In addition, this study has revealed no differences in the Type A, UTF, AF, and RTF prevalence between the sub-Saharan African (all subjects) and the Caucasian subjects. These variations may be known by surgeons before spine surgery for better planning.