MDCT of an Aberrant Right Subclavian Artery and of Bilateral Vertebral Arteries with Anomalous Origins

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.

Anomalous Origin and Course of Right Vertebral Artery With Aberrant Right Subclavian Artery

Origin and course anomalies of the vertebral arteries are rare. They are considered a congenital anomaly that occurs in the early stages of embryonic development. Thanks to magnetic resonance angiography, these anomalies can be diagnosed easily. Detecting these anomalies is especially important before endovascular interventional procedures. In this case report, we present magnetic resonance angiography findings of a patient with extraforaminal vertebral artery that originated from right common carotid artery and also with aberrant right subclavian artery.

The right vertebral artery originating from the right occipital artery and the absence of the transverse foramen: a rare anatomical variation

Variations in the origin of the vertebral artery (VA) is a congenital anomaly that occurs during embryological development. Multiple variations related to VA origin have been reported in the literature. Abnormal VA origin is usually determined as incidental findings during angiographic or postmortem anatomical studies. Although most of the cases are asymptomatic, in patients with VA anomaly symptoms such as dizziness have been described. The anomalous variation in the origin of the right VA is rare and separated into three categories: (1) originating from the aorta, (2) originating from the carotid arteries, (3) duplicated origin. In this case, we aimed to present the right VA originating from the right occipital artery and concomitant anomalies of the transverse foramen that have not been reported previously according to our knowledge in literature. In a 32-year-old female patient referred to our hospital because of dizziness, the right VA was not observed on magnetic resonance imaging and computed tomography angiography (CTA) examination was performed. CTA showed hypoplasia of the right transverse foramen at the levels of the C1, C5 and C6 vertebrae and aplasia of the right transverse foramen at the levels of the C2, C3 and C4 vertebrae. The right VA originating from the right occipital artery continues to its normal course by entering the cranium through the foramen magnum at the level of the atlantooccipital junction.

Anomalous Origin of the Right Vertebral Artery: Incidence and Significance

OBJECTIVE

Detailed knowledge about anatomic variations of the aortic arch and its multiple branches is extremely important to endovascular and diagnostic radiologists. It is often hypothesized that anomalous origin and distribution of large aortic vessels may alter the cerebral hemodynamics and potentially lead to a vascular pathology.

METHODS

In this article, we describe a case of anomalous origin of the right vertebral artery, which was detected during an intervention. We further reviewed the available literature of anomalous origin of the right vertebral artery. The probable embryologic development and clinical significance are discussed.

RESULTS

The incidence of anomalous origin of a vertebral artery seems to be underestimated in recent literature. A careful review of the literature shows more than 100 such cases. The right vertebral artery can arise from the aortic arch or one of its branches. Dual origin of the vertebral artery is not uncommon. The embryologic developmental hypotheses are contradictory and complex.

CONCLUSIONS

Anomalous origin of the right vertebral artery may not be the sole reason behind a disease process. However, it can certainly lead to a misdiagnosis during diagnostic vascular studies. Detailed information is essential for any surgery or endovascular intervention in this location.

Hybrid endovascular treatment of an aberrant right subclavian artery with Kommerell aneurysm

Aberrant right subclavian artery is a rare anatomical finding of abnormal embryologic development of the dorsal aorta and right subclavian artery. An associated aortic outpouching, or Kommerell diverticulum, may develop at the origin of the aberrant right subclavian artery. Given historically high rates of aneurysm rupture and mortality, early repair is indicated. Successful aneurysm exclusion can be accomplished with thoracic endovascular stent grafting following open carotid-subclavian bypass, maintaining upper extremities perfusion. Such hybrid techniques offer a decrease in mortality and complication rates. Herein, we describe a successful repair of a symptomatic (dysphagia, weight loss) aberrant right subclavian artery with Kommerell diverticulum using this hybrid open-endovascular approach.

Variations in the origin of the vertebral artery and its level of entry into the transverse foramen diagnosed by CT angiography

INTRODUCTION

The origin of the vertebral artery (VA) varies, though most VAs enter the transverse foramen (TF) of the sixth cervical vertebra. On computed tomography (CT) angiographic images, we evaluated the prevalence of variations of both VA origin and its level of entry into the TF.

METHODS

We retrospectively reviewed CT angiographic images of 2,287 patients obtained using either of two 64-slice multidetector CT scanners. All patients were Japanese and underwent scanning from the aortic arch to the intracranial region; most had or were suspected of having cerebrovascular diseases.

RESULTS

The left VA (LVA) arose from the aorta between the left common carotid artery and left subclavian artery in 94 patients (4.1 %) and in other variations in 44 patients (1.9 %). The right VA (RVA) arose from the extreme proximal segment of the right subclavian artery in 72 patients (3.1 %) and in other variations in 14 patients (0.6 %). The LVA entered the sixth TF in 2,127 patients (93.0 %), and the RVA entered the sixth TF in 2,146 patients (93.8 %). Anomalous origin and anomalous entry level into the TF correlated strongly.

CONCLUSIONS

The total prevalence of variation in the origin of the LVA was 6.0 % and of the RVA, 3.8 %. The total prevalence of variation in entry level into the TF was 7.0 % for the LVA and 6.2 % for the RVA. Recognition and reporting of these variations is important in interpreting CT angiography to prevent complications during surgery of the aortic arch or lower neck.

Interpretation of multi-detector computed tomography images before dissection may allow detection of vascular anomalies: a postmortem study of anomalous origin of the right subclavian artery and the right vertebral artery

The Graduate School of Medicine at Chiba University is planning to introduce computed tomography (CT) images of donated cadavers to the gross anatomy laboratory. Here we describe an anomaly of the right subclavian artery that was detected by interpretation of CT images prior to dissection. The anomaly was verified to be the right subclavian artery, as the last branch of the aortic arch, by subsequent dissection of the cadaver. We also identified an anomalous origin of the right vertebral artery by dissection. This anomaly was also visible on CT images, although it had not been recognized in the first interpretation of the CT images. Our results suggest that branching anomalies of arteries with a diameter of >1 cm are detectable on CT images even without the injection of contrast medium. We also discuss the utility of interpreting CT images prior to dissection as a means by which medical students can gain a better understanding of human body during the gross anatomy laboratory.

A right-left aortic arch pattern made up by a bicarotid trunk, a left subclavian, a left vertebral and a right retroesophageal subclavian artery

We present several vascular variations of the aortic arch vessels observed in a 35-year-old man during magnetic resonance angiography (MRA). The arterial branches of the aortic arch are from right to left: a bicarotid trunk, a left vertebral artery, a left subclavian artery, and a right retroesophageal subclavian artery. The right vertebral artery arises from the right carotid artery. Although a right retroesophageal subclavian artery has been reported in association with different anatomic variations of the aortic arch, to our knowledge this is the first MRA description of this particular combination of variations.

Multidetector CT scan findings of a right aberrant retroesophageal vertebral artery with an anomalous origin from a cervical aortic arch

Various malformations of the aortic arch and great vessels have been reported in the literature, which reflects the complexity of their embryologic development. Most of them are of incidental finding and remain asymptomatic but can be responsible for respiratory or digestive symptoms and be associated with congenital cardiac diseases. We report the case of a patient presenting a right retroesophageal vertebral artery. This malformation was associated with multiple anomalies of the aortic arch. We report a classification of the most common aortic arch abnormalities by recalling Edwards double aortic arch model and embryologic variants. Here, we report on the rare case of a right retroesophageal vertebral artery. We assimilate this malformation to a vertebral arteria lusoria and attribute it to the lack of caudal migration of the fourth branchial arch, responsible for a left cervical aortic arch with an interruption between the right subclavian and vertebral arteries.

Dissection of arteria lusoria by transradial coronary catheterization: a rare complication evaluated by multidetector CT

An aberrant right subclavian artery (arteria lusoria) arising from the descending thoracic aorta is an uncommon congenital variant that occurs in about 0.2-1.7% of the population. In such cases, the angular course of the arteria lusoria to the ascending aorta imposes difficulty in passing a guide wire to the ascending aorta during right transradial catheterization. Here, we present the first report of an iatrogenic dissection of arteria lusoria during transradial coronary angiography evaluated by multidetector computed tomography. Computed tomography is useful for assessing the severity and extension of the dissection to guide the clinical management of this complication.

Two cases of aberrant right subclavian artery and right vertebral artery that originated from the right common carotid artery

We present here two patients that had an aberrant right subclavian artery and an anomalous origin of the right vertebral artery from the right common carotid artery. We review the previous literature and discuss herein the embryologic mechanism and clinical implications of this variation.