Congenital external carotid-internal carotid artery anastomosis: a report of three cases and literature review.

PURPOSE: Congenital external carotid-internal carotid artery (EC-ICA) anastomosis is a cervical arterial variation that was initially reported, based on anatomic dissection, from Japan in 2000. The purpose of this report is to show the characteristic radiological findings of this extremely rare cervical arterial variation. METHODS: We analyzed nine cases, including six previously reported cases and three cases that we recently experienced. Three of the six previously reported cases were from Japan, and the remaining three cases were from Korea. MR angiography (4), CT angiography (2), catheter angiography (2) and autopsy (1) were used as diagnostic modalities. RESULTS: The study population included eight men and one woman. Anastomosis was seen on the left side in seven cases and the right side in two cases, and it was located at the level of the C1/2-C2/3 intervertebral space. In all cases, ECA was larger than the ICA at the level of their origins. In four cases, the ICA was extremely small in caliber. In one case, the ICA may have been occluded postnatally, and its configuration was similar to that of the nonbifurcating cervical carotid artery (CCA). With the exception of this occluded case, the carotid bifurcation and EC-ICA anastomosis formed a large arterial ring in all cases. CONCLUSION: EC-ICA anastomosis can be regarded as a variant of the nonbifurcating CCA because if the most proximal segment of the small ICA is occluded, nonbifurcating CCA may form. EC-ICA anastomosis is located between the C1/2-C2/3 intervertebral space and may be formed by the remnants of the proatlantal artery I.

Variations in origin of the superior thyroid artery: an update for the head and neck surgeon.

Head and neck surgeons must have a thorough knowledge of head and neck vascular anatomy and its variations. This case report documents a variation in the superior thyroid artery encountered during a neck dissection and discusses the surrounding literature. A 55-year-old female with squamous cell carcinoma of the tongue underwent a partial glossectomy, right level I-IV neck dissection and reconstruction with a radial forearm free flap. During the procedure, an arterial branch was encountered arising 2-3cm caudal to the common carotid bifurcation. This variant branch was shown to represent the superior thyroid artery. On review of the literature, various classification systems of the superior thyroid artery origin have been described. Awareness of such anatomical variation is vital for the head and neck surgeon to avoid unexpected complication.

Ascending pharyngeal artery-posterior inferior cerebellar artery anastomosis via the jugular foramen: a case report and literature review.

The posterior inferior cerebellar artery (PICA) rarely arises from the cavernous segment of the internal carotid artery (ICA) and is called persistent trigeminal artery variant. The PICA also can arise from the cervical segment of the ICA, and it enters the posterior fossa via the hypoglossal canal, where it is called persistent hypoglossal artery variant. Using magnetic resonance angiography (MRA), we diagnosed a 79-year-old man with a PICA arising from the ascending pharyngeal artery and passing through the medial side of the jugular foremen pars vascularis. Only six cases of this variation have been reported previously in the English language literature. To identify this variation on MRA, the careful observation of source images is useful. Recognizing this variation is important in order to avoid ischemic cerebellar complications during neck surgery and endovascular therapy.

Simple Things Are Not Simple: Pulsatile Tinnitus due to Tortuous Occipital Artery.

BACKGROUND: Pulsatile tinnitus is often a chronic and debilitating condition and normally has a vascular origin. We describe a case of pulsatile tinnitus due to an aberrant branch of the external carotid artery (ECA), which has not been reported previously. METHOD: A 67-year-old female with chronic unilateral pulsatile tinnitus, which could be controlled completely with direct pressure on a small tortuous superficial branch behind her left ear. This was confirmed with doppler to be an unusually tortuous occipital branch of the ECA. Under local anesthesia, this vessel was identified with intraoperative doppler and ligated. RESULT: Complete resolution of tinnitus immediately, with consistent results 3 months postoperatively. CONCLUSIONS: Pulsatile tinnitus due to aberrances in the occipital ECA branch is rare, and in this case, was successfully treated with minor surgery.

Separate arch origin of the left external carotid artery with common trunk giving rise to the left internal carotid artery and left subclavian artery.

We present a case of a 3-year-old boy with tetralogy of Fallot having the direct origin of the left external carotid artery from the aorta with a common trunk giving rise to the left internal carotid artery and left subclavian artery, in a right-sided aortic arch. We also highlight the potential implications in management.

A symptomatic atherosclerotic persistent pharyngo-hyo-stapedial artery: Treatment management and embryological considerations.

The stapedial artery (SA) is an embryonic vessel connecting the internal carotid artery (ICA) to the branches of the future external carotid artery (ECA). It passes through the primordium of the stapes that progressively develops around the SA. Normally, SA disappears during the tenth week in utero. Approximately 0.4% of the population can have a persistent SA. It can persist as four types of embryological variations, of which the pharyngo-hyo-stapedial variant has been rarely described before. We reported a case of a 61-year-old woman presented with transient ischemic attacks (TIAs). Computed tomography angiography showed an unusual "duplicated" aspect of the left ICA. Digital subtraction angiography depicted a persistent pharyngo-hyo-stapedial artery with an atherosclerotic wall and was considered the cause of the TIAs. After failure of the antiplatelet therapy in preventing recurrent TIAs, stenting of the artery was planned and successfully performed. Patient was asymptomatic during 12-month follow-up. The pharyngo-hyo-stapedial artery is a very rare variation in which the SA is supplied by the inferior tympanic (rising from the ascending pharyngeal artery) and the hyoid artery (rising from the ICA). To our knowledge, this is a unique case of a pharyngo-hyo-stapedial artery in a patient presenting associated ischemic symptoms. Radiological and embryological findings are discussed.

Origin variations of the superior thyroid, lingual, and facial arteries: a computed tomography angiography study.

PURPOSE: To determine the anatomical variations and morphology of the external carotid artery (ECA) and its anterior branches. METHODS: Using computed tomography angiography (CTA), the origin, internal diameter, and surface laterality emergence of the superior thyroid (STA), lingual (LA), and facial (FA) arteries were evaluated retrospectively evaluated and classified. The bifurcation level of the common carotid artery (CCA) in relation to the cervical vertebrae and disc was also determined. RESULTS: A total of 76 CTA were included in the study. STA originated from the carotid bifurcation (CB) (type I), CCA (type II) and ECA (type III) in 20.4 (31/152), 17.1 (26/152) and 50.7% (77/152) cases, respectively. Also 10.5% (16/152) arose from a shared trunk with LA as a thyrolingual trunk (TLT) (type IVa), and absent in 1.3% (2/152). LA originated in the CB in only one case. A linguofacial trunk (LFT) was present in 14.5% (22/152). Mean diameters of STA, LA and FA were 1.70, 1.95 and 2.45 mm, respectively. Meanwhile, surface laterality were predominately from anteromedial, medial, and anterior, respectively. CB was mainly on C3 or C3-C4 (55.9% of cases). CONCLUSIONS: STA origin below the ECA is a common finding. Our population presented the highest percentage of TLT (10.5%) and high CB (9.8%) in literature. Considering these variations are important to prevent complications in neck surgical procedures.

Bilateral persistent stapedial arteries associated with unilateral moyamoya disease: a particular anatomic variant.

PURPOSE: The persistence of the stapedial artery is a rare vascular variant that could explain the origin of the middle meningeal artery from the petrous segment of the internal carotid artery. The anatomic variations are illustrated and a summary of the possible hypothesis of the origin of the middle meningeal artery from the internal carotid artery is discussed, analysing the embryological works of the Carnegie Institute and the vascular development of the middle meningeal. METHODS AND RESULTS: The authors present a young patient showing a particular vascular variant on diagnostic imaging. These showed a bilateral internal carotid artery that gives origin of the middle meningeal artery in a patient affected by moyamoya disease. A literature review was performed to analyze the particular variant of the radiologic anatomy. CONCLUSION: The internal carotid artery origin of the middle meningeal artery is a wonderful anatomic variant that permits to understand the complex embryological development and then involution of the stapedial artery.

Case report of unique anastomosis between facial and inferior alveolar arteries.

PURPOSE: Understanding anatomical variations of the facial artery and its branches is important for dental and medical practitioners. METHODS: Routine cadaveric dissection of the head and neck was performed to demonstrate the origin and branches of the facial artery. RESULTS: Facial artery emerged from a common linguofacial trunk off the external carotid artery. On the face, the facial artery first gave off a pre-masseteric branch. Immediately after, an aberrant artery emerged from the facial artery that coursed along the ramus of the mandible, which upon further dissection and examination was found to anastomose with inferior alveolar artery within the ramus of the mandible. CONCLUSIONS: We report a unique anastomosis between facial and inferior alveolar arteries, vessels that have not been previously shown to communicate. This case report may provide useful information for oral and maxillofacial surgeons as well as dentists performing inferior alveolar nerve blocks.

Anomalous anastomosis between the external carotid artery and vertebrobasilar artery via the hypoglossal canal: a case report and review of literature.

We report a case of an anomalous anastomosis formed between the external carotid artery (ECA) and the vertebrobasilar artery (VBA) and passing through the hypoglossal canal. A carotid-vertebrobasilar anastomosis of this kind is typically considered a variant of persistent primitive hypoglossal artery which usually originates from the internal carotid artery. However, the anastomotic vessel in this case had a common trunk with the occipital artery (OA), a remnant of the primitive proatlantal artery. The proximal and distal parts of the anastomotic vessel seemed to have been derived from the primitive proatlantal artery and the primitive hypoglossal artery, respectively. Thus, we propose that this ECA-VBA anastomosis, which passed through the hypoglossal canal and had a common trunk with the OA, be referred to as a dilated primitive hypoglossal-proatlantal anastomosis; that is, a dilated ascending pharyngeal artery rather than a variant of persistent primitive hypoglossal artery.

Prevalence of Anomalously Originating Occipital Artery in a Group of Turkish Individuals: A Retrospective Study using Angiography.

AIM: To investigated the prevalence of anomalously originating occipital artery (OA) using angiography in a group of Turkish individuals. MATERIAL AND METHODS: The images recorded in the picture archiving and communication system for a total of 114 patients, in which the whole vertebral artery, as well as the external carotid artery (ECA) and its branches, were visualized, were retrospectively reviewed. Images were obtained using a Toshiba INFNX-i 8000V (Canon Medical Systems, Otawara, Tochigi, Japan) angiography device. RESULTS: We diagnosed 11 cases (12 arteries) with anomalously originating OA, representing a prevalence of 9.64%. In 7 cases, the ascending pharyngeal artery and OA originated with a common root from the ECA (8 arteries); and in 4 patients, OA originated from the distal part of the ECA (C1 vertebral level). CONCLUSION: As for many vascular structures, the prevalence of OA variations may vary according to the population under question and the examination method used. Our study has shown that in a sample from the Turkish population, the prevalence of anomalously originating OA was much higher than that stated in the literature, which used magnetic resonance angiography. To avoid complications, the high prevalence of this anomaly must be taken into account during surgeries that require the use of OA, endarterectomies, and endovascular interventions.

An Anatomical Variation in the Cervical Carotid Artery of a Young Stroke Patient.

The cervical carotid artery has been reported to show anatomical variations. We report the case of a young stroke patient with a small right-parietal-lobe infarction whose cervical carotid artery showed anatomical variation. The right internal carotid artery (ICA) originated at the C2 level of the external carotid artery with protrusion at the right carotid bifurcation. The vessel wall of the protrusion showed a high signal intensity on T1-weighted magnetic resonance carotid plaque imaging. The protrusion, considered a remnant of the ICA, possibly caused the stroke due to the formation of thrombi as a result of changes in blood flow and viscosity.

A rare case report of a mixed persistent proatlantal intersegmental artery.

Adults with persistent proatlantal intersegmental artery (PPIA) are rarely seen. We present a case of a special type of PPIA that was in a 57-year-old man who presented with dizziness and episodic vertigo of 9 months duration. The diagnosis relied on computed tomography angiography and digital subtraction angiography, by which a left internal carotid artery stenosis and an ipsilateral PPIA originating from the external carotid artery (ECA) was found. This special type of PPIA can be described as a ''mixed PPIA'' that originated as Type II from the ECA and coursed as Type I. The patient underwent carotid artery stenting and had no relapse during 3 months follow-up. In addition, the literatures on PPIA were reviewed.

Nonbifurcating Carotid Artery: A Case Report with a Review of Embryogenesis.

BACKGROUND Vascular anomalies of the carotid vessels can be attributed to false embryogenesis. A rare variant called a nonbifurcating carotid artery (NBCA) exists, where typical carotid bifurcation is not recognizable with its typical branches of the external carotid artery (ECA) and internal carotid artery (ICA). This paper describes a case of this anomaly and reviews the embryogenesis of the carotid arteries for explanation. CASE REPORT A 66-year-old man received a routine health examination at our hospital. Initial carotid ultrasound indicated an absence of bifurcation in the right cervical carotid artery, and magnetic resonance imaging of the brain indicated an absence of the proximal cervical segment of the right ICA, with a remnant arterial stump at the expected bifurcation level. No evidence of the carotid bulb was identified. The common carotid artery seemed to continue cranially in the trunk of the ECA, where it exhibited extracranial branches. After distributing these branches, the carotid artery coursed medially at the C2 level, where it ascended into the carotid canal to become the petrosal segment of the ICA. This carotid anomaly was labelled an NBCA. No aberrant intracranial arteries were derived from the NBCA in this case. CONCLUSIONS In this case, the arterial stump was considered a remnant from agenesis of the right ICA. We assumed that the NBCA most likely developed because of false regression of the third embryogenic aortic arch with persistence of the second aortic arch.