Occipital artery arising from the superior aspect of the carotid bifurcation identified by three-dimensional computed tomography angiography

Variation of the branches of the external carotid artery is well known, but it is extremely rare for the occipital artery (OA) to arise from the carotid bifurcation (CB). A 73-year-old man was found to have this anatomical variation on the right side by three-dimensional CT angiography for vascular mapping of the carotid arteries before superselective intra-arterial catheterization. The OA arose from the CB and the inner diameter of the origin of the OA was 1.5 mm. The CB was located at the level of C3–C4 and 7.9 mm above the tip of the greater horn of the hyoid bone.     

Persistent dorsal ophthalmic artery and ophthalmic artery arising from the middle meningeal artery diagnosed by MR angiography at 3 T

Introduction

A persistent dorsal ophthalmic artery (OA) is a rare variation that originates from the cavernous segment of the internal carotid artery (ICA) and enters the orbit via the superior orbital fissure (SOF). Occasionally, the OA also arises from the middle meningeal artery (MMA) and enters the orbit via the SOF. These two major variations of the OA have not been well described by magnetic resonance (MR) angiography. We evaluated their prevalence on MR angiography at 3 T.

Methods

We retrospectively reviewed our database of MR angiographic images obtained using a 3 T imager. Of images of 846 patients, we evaluated those of 826 patients (1,652 OAs) with special attention to OA origin and its course into the orbit. We excluded images of the 20 because quality was insufficient to assess.

Results

We found 7 (0.42 %) persistent dorsal OAs among 1,652 OAs (right/left, 6/1; male/female, 3/4). Twenty-four (1.45 %) OAs arose from the MMA (right/left/bilateral, 11/5/4; male/female, 10/10), three of which also demonstrated a small normally branching OA. In one patient, we observed both right persistent dorsal OA and left OA arising from the MMA.

Conclusions

Per OA, the prevalence of persistent dorsal OA was 0.42 % and of OA arising from the MMA, 1.45 %, with a tendency toward right-side predominance. OA arising from the MMA can be seen bilaterally; preprocedural knowledge of this variation is important because of the danger associated with endovascular procedures of the external carotid system when the OA arises from the MMA.     

High bifurcation of common carotid artery, anomalous origin of ascending pharyngeal artery and anomalous branching pattern of external carotid artery

We present a rare case of combined high bifurcation of the common carotid artery, anomalous origin of the ascending pharyngeal artery and unusual branching pattern of the external carotid artery. The right common carotid artery bifurcated at the level between the second and the third cervical vertebrae, giving rise to the ascending pharyngeal artery just below the bifurcation. The right external carotid artery branched directly at its origin into the superior thyroid, lingual and occipital arteries and the distal part of the external carotid artery. The latter gave rise to the right facial artery and finally bifurcated into the maxillary and superficial temporal arteries. The right posterior auricular artery arose from the right occipital artery. The finding was unilateral and other vascular anomalies were not observed. The embryogenesis of such a combination of anomalies is not clear, but the anatomic consequences may have important clinical implications.     

Truncus bicaroticus with aberrant right subclavian artery and origin of right vertebral from right common carotid artery

We describe a rare constellation of variant anatomy of the aortic arch branches, seen on a magnetic resonance angiographic examination during the course of investigation for recent onset memory loss in a 52-year-old patient. There was a common origin of both the common carotid arteries (CCA), the common trunk being the first major branch of the aortic arch, the right vertebral artery arising from the right CCA and the right subclavian artery arising as the last branch of the arch. In isolation, the three components of this constellation have been reported with different frequencies, but as per the authors’ knowledge, this entire constellation has been rarely reported. We review the literature and propose an embryological mechanism for this variant anatomy.     

Different ophthalmic artery origins: Embryology and clinical significance

This retrospective study gives a summary of ophthalmic artery (OA) variations to serve as guidelines for surgical interventionists and trainees. Pubmed and Medline searches were conducted. The OA usually arises intradurally (superomedial, anteromedial, or rarely superolateral) from the internal carotid artery (ICA). Rare extradural origin (primitive dorsal OA) (PDOA) remnant and extremely rare interdural origin (primitive ventral OA) (PVOA) remnant are of significance when sectioning the dural ring. Rarely, a persistent PDOA with ICA origin, or a PDOA remnant with inferolateral trunk origin, enters the orbit via the superior orbital fissure (SOF) for sole or partial orbital supply. Extremely rare, the PDOA and PVOA persist and form double OAs that arise from the ICA and run via the SOF and optic foramen. Occasionally, the OA arises from the middle meningeal artery (MMA), when both the PDOA and VDOA regress and enter the orbit via the SOF. Sole orbital supply via the external carotid artery (ECA), i.e. meningo‐ophthalmic artery and/or MMA branches, or dual OAs (ECA and ICA origins) may occur. Other rare OA origins include anterior or posterior communicating artery; anterior or middle cerebral artery; basilar artery; posterior inferior cerebellar artery; and the carotid bifurcation. Primitive arteries (persistent or remnant), and/or abnormal anastomoses play pivotal roles in manifestations of OA variations. Of clinical importance are orbital collateral routes and dangerous extracranial‐intracranial anastomoses. Awareness of OA origins and collateral routes is imperative for transarterial embolizations or infusion chemotherapy in the ECA territory to prevent visual complications. Clin. Anat. 28:576–583, 2015. © 2014 Wiley Periodicals, Inc.     

甲状腺上动脉的起始位置及临床意义

目的　探讨甲状腺上动脉的起始情况及其临床意义。 方法　解剖118具用福尔马林固定的尸体的双侧颈区,观察甲状腺上动脉的起始情况以及起始部位到颈总动脉分叉处的距离,并进行统计学分析。 结果　甲状腺上动脉的起始情况可分为颈总动脉分叉处（A）、颈外动脉（B）和颈总动脉（C）三种,所占比例分别为30.93%,37.71%和30.51%;左右两侧甲状腺上动脉起始情况分布有显著差异（P<0.05）;起始于颈外动脉的甲状腺上动脉起始处距颈总动脉分叉处的距离小于起始于颈总动脉的甲状腺上动脉起始处距颈总动脉分叉处的距离。 结论　甲状腺上动脉是头颈部外科手术中具有重要临床意义的动脉,其回顾性分析将为临床应用提供解剖学依据。     

Duplication of the left vertebral artery in a patient with dissection of the right internal carotid artery and Ehlers–Danlos syndrome: case report and review of the literature

Duplication of the left vertebral artery was observed in a 43-year-old Caucasian male with dissection of the right internal carotid artery during multidetector 64-row computer tomography and Doppler ultrasonography B-flow mode. Both duplicated segments arose from the left subclavian artery and united at levels C5–C6 to form a single vessel. The presented case describes precisely the origin and diameter of both vertebral arteries. Additionally, after all procedures associated with diagnosis and treatment of the patient, Ehlers–Danlos syndrome type IV was diagnosed. The lumen of the duplicated vertebral artery was smaller than normal; it can be concluded that this variant has clinical implications and should be taken into consideration when vertebral arteries need catheterization.     

Variant origin of the superior thyroid artery in a Kenyan population

Variant anatomy of the superior thyroid artery is important during surgical procedures, interpretation of angiograms, and interventional radiography in the neck. Pattern of the variations shows population differences but there is no data from the Kenyan population. This study therefore investigated the variations in origin of the superior thyroid artery in a Kenyan population. Forty six necks (36 males and 10 females) from 46 cadavers of black Kenyans in Department of Human Anatomy University of Nairobi, Kenya were bilaterally dissected to expose the origin of the superior thyroid artery. Pattern of origin of the vessel was determined on both sides in males and females. It originated from the external carotid artery common carotid artery and linguo-facial trunk in 80%, 13%, and 6.5% of the cadavers respectively on the right side. All but one of the superior thyroid arteries were ventral branches. There was asymmetric origin in 6.5% of cases. Origin from the common carotid artery was associated with high carotid bifurcation. Nearly 20% of superior thyroid arteries showed variant origin. Of these, 6.5% arose from the linguo-facial trunk, much higher than in the Caucasian and Oriental populations. Origin from common carotid artery is substantially lower than prevailing figures from other populations. These findings support ethnic variations. Preoperative angiographic evaluation is recommended.     

A fusiform aneurysm of a persistent trigeminal artery variant: case report and literature review

A 48-year-old man suffered from spontaneous subarachnoid hemorrhage. Emergent right internal carotid angiography showed the presence of a persistent trigeminal artery (PTA) variant with a fusiform aneurysm on its proximal segment where it branched from the internal carotid artery. This artery supplied the territory of the anterior inferior cerebellar artery. After consideration of the adequacy of the cerebellar circulation without this anomalous artery, intraluminal occlusion of the aneurysm together with the PTA variant was performed using detachable coils. The patient recovered uneventfully without any neurologic deficits.     

Central retinal artery originating from the temporal short posterior ciliary artery associated with intraorbital external-to-internal carotid arterial anastomoses

Although variations in the peripapillary division pattern of the central retinal artery (CRA) are common, variations in the origin of this artery are seldom reported in the literature. Herein, the authors report a variant of the CRA that originated from the temporal short posterior ciliary artery. Two intraorbital anastomoses were also noted between the internal and external carotid arterial systems: one through the lacrimal artery–middle meningeal artery to the ophthalmic artery and the other through supraorbital artery–recurrent meningeal artery to the ophthalmic artery. A brief review of CRA variations and potential clinical significances of the observed variant are discussed.     

头臂干缺如及其分支变异1例并文献复习

目的:报道头颈部血管起源变异,探讨其临床意义.方法:对相关病例作全脑血管造影检查,显示起源变异血管的分布情况.结果:头臂干缺如,右侧颈总动脉、右侧锁骨下动脉直接起源于主动脉弓,右侧椎动脉起源于右侧颈总动脉.结论:右侧椎动脉起源位置变异可能与诱发短暂脑缺血发作有关.     

Anomalous artery directly connecting the external and internal carotid arteries

An anomalous artery directly connecting the external with the internal carotid artery was encountered on the right side of a 68-year-old Japanese female cadaver. This anomalous artery (5 mm in diameter, 12 mm in length) branched out from the posterior aspect of the external carotid at the level of the origin of the lingual artery, ran obliquely upward posteriorly along the course of the hypoglossal nerve, and was confluent with the anterior aspect of the internal carotid artery. No other variations were found in the morphological aspects of, or in the anatomical relationships between, the carotid arteries and their surrounding structures on either side. The carotid body-like structure was observed at the carotid bifurcation and was innervated by small branches of the glossopharyngeal, the vagus and the sympathetic trunk. Embryologically, it is conceivable that this anomalous artery may have derived from the right second branchial arch artery, although there is no abnormality in other derivative structures of the second pharyngeal arch. There may have been no effect from this anomaly on the functions of the arterial blood flow and blood supply under normal circumstances in the present case, but this report may be of embryological significance and contribute some insight into the mechanisms of the formation of the carotid circulation systems.     

Thyrolingual trunk arising from the common carotid artery identified by three-dimensional computed tomography angiography

It is well-known that the branches of the external carotid artery (ECA) can show anatomical variation, but it is extremely rare that thyrolingual trunk originates from common carotid artery (CCA). Here we report a case of the thyrolingual trunk arising from the CCA on the right side in a 73-year-old female as revealed by three-dimensional computed tomography angiography for vascular mapping of the carotid vessels before head and neck microsurgical reconstruction. The thyrolingual trunk arose from the anterior surface of the right CCA, with an origin 14.5 mm (difference between the carotid bifurcation and upper border of the origin 12.7 mm) below the carotid bifurcation. The inner diameter of origin of the thyrolingual trunk was 3.5 mm, and the angle between the thyrolingual trunk and the CCA was 130°. After a 10.2-mm course, the thyrolingual trunk divided into the superior thyroid artery (STA) and lingual artery (LA). The inner diameters of the origins of the STA and LA were 1.7 and 1.9 mm, respectively, and the angle between the branches was 94°. It is important to recognize this anatomic variation of the branches of the ECA before the microsurgical reconstruction or super-selective intra-arterial chemotherapy for head and neck cancer.     

Visualization of the ophthalmic artery by phase-contrast magnetic resonance angiography: a pilot study

Objective

This study aimed at investigating whether phase-contrast (PC) magnetic resonance (MR) angiography is useful for visualizing the ophthalmic artery (OA).

Methods

This prospective study enrolled 196 consecutive outpatients who underwent three-dimensional PC MR angiography. The basal image parallel to the anteroposterior dimension of the OA was extracted for analysis from the imaging data.

Results

The 99 male and 97 female subjects were aged from 10?years to 80?years (mean 47.9?years). The OAs were supplied only by the external carotid system or in combination with the internal carotid artery (ICA) in 18 subjects (9.2?%). The bilateral OAs were symmetrical in 12?%, asymmetrical in 87?%, and unidentified in 1?%. The contour of the proximal segment of the OAs could be classified into straight, curved, and tortuous types. The ICA–OA angle defined by the angle between the approximate line of the proximal OA and the vertical line was also variable. The first bend of the OA corresponded to the anastomosis site with the external carotid system. The proximal medial bend was the origin of the posterior ethmoidal artery, and the distal medial bend was the origin of the anterior ethmoidal artery.

Conclusions

According to the results the OA not only possesses three characteristic bends, but also shows prominent individual variability and commonly shows bilateral asymmetry. The contour of the OA may be regulated by the anchor effect at the bend sites. PC MR Angiography is useful for visualizing the main trunk of the OA.     

A case of the thyroidea ima artery arising from the aortic arch

The present report describes a case of the thyroidea ima artery observed in a 65-year-old Japanese male on dissection in 1988. The thyroidea ima artery arose from the aortic arch between the branchiocephalic trunk and the left common carotid artery. The thyroidea ima passed to the left lobe and isthmus of the thyroid gland for the supply of these. The inferior thyroid artery on the right side was of common type in its origin and course, though that on the left side was absent. Either of the superior thyroid arteries arose from the common carotid artery.     

A retroesophageal right subclavian artery with the right vertebral artery originating from the right common carotid artery

The right subclavian artery was found to be retroesophageal, and the right vertebral artery originated from the right common carotid artery in a 46-year-old female cadaver. The right subclavian artery stemmed from the upper portion of the thoracic aorta, posterior and inferior to the origin of the normal left subclavian artery. The right and left common carotid arteries originated from the aortic arch in close proximity. Compression of the trachea anteriorly could not be demonstrated. The right inferior laryngeal nerve was nonrecurrent. A brief review of the literature shows the importance of knowledge concerning the aberrant right subclavian artery for the roentgenologist and the surgeon in the treatment of patients with this vascular anomaly.     

Anomalous origin of both vertebral arteries

The authors describe a case of an unusual origin of both vertebral arteries in a singular cadaver. On the left, the artery arises directly from the common trunk of vertebral and subclavian artery at the aortic arch and enters the transverse cervical foramina at C VI. On the right, the artery originates from the right common carotid artery and enters the transverse foramina at C III. Additional anomalies were observed on the aortic arch: the common trunk of both common carotid arteries, the common trunk of the left vertebral and subclavian artery, and as a last branch, the retroesophageal right subclavian artery. The morphometric measurements of the vertebral arteries were performed. The literature on the variations of the vertebral arteries is reviewed and their clinical importance for diagnostical procedures and head and neck surgery stressed. Clin. Anat. 12:281–284, 1999. © 1999 Wiley‐Liss, Inc.     

An aberrant cerebellar artery originating from the internal carotid artery

The aberrant origin of the cerebellar arteries from anterior cerebral circulation is a quite rare vascular variation. Herein, we report a 52-year-old white female with angiographically occult subarachnoid hemorrhage. Left superior and anterior inferior cerebellar arteries were not detected. An aberrant cerebellar artery was noted to arise from the left cavernous internal carotid artery and terminated in the distribution of the ipsilateral superior and anterior inferior cerebellar arteries. This variant artery might likely have resulted from an abnormal regression of fetal anterior-to-posterior circulation connections, and may represent a fetal-type cerebellar artery. A review of the anatomy and clinical significance of the variant is presented.     

Internal carotid artery agenesis with stenosed intercavernous anastomosis:a case report

We report a rare case of internal carotid artery agenesis with stenosed intercavernous anastomosis.A 59-yearold male patient presented with a new infarction in the left basal ganglia.Magnetic resonance angiography and cerebral angiography showed that the right internal carotid artery disappeared from the origin to the foramen lacerum segment,and there was an anastomotic artery with severe stenosis passed through the floor of the sella and in front of the cavernous sinus.The right A1 segment of the anterior cerebral artery was absent and A2 segment was supplied by the normal contralateral internal carotid artery via the anterior communicating artery.