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.

Morphological, embryological, and clinical implications of the bi-carotid trunk, aberrant right subclavian artery, and bilateral linguofacial trunk.

A female cadaver fixated with 10% formalin solution was dissected during a routine undergraduate anatomy class. It was found that both the right and left carotid arteries arose from a bi-carotid trunk as the first branch of the aortic arch. The bi-carotid trunk was followed by the left subclavian artery. The aberrant right subclavian artery (the last branch) had a retro-oesophageal course. These variations were associated with the linguofacial trunk bilaterally. The group of variant anatomy of vessels encompassing the bi-carotid trunk, aberrant right subclavian artery, and the linguofacial trunk is extremely rare. A similar case has not been reported yet in the literature. The anatomic and morphologic variations of the aortic arch and its branches are important for diagnostic and surgical procedures in the thorax and neck region. Thoracovascular surgeons and interventional radiologists should be aware of these anomalies during head and neck surgery, aortic instrumentation, and four-vessel angiography.

MR angiographic findings of aberrant right subclavian artery with agenesis of the left common carotid artery and anomalous origin of the vertebral arteries.

INTRODUCTION: Congenital aortic arch anomalies and variants have been extensively characterized in the medical literature. Proper identification of these anomalies is important when surgical or percutaneous interventions are indicated. CASE PRESENTATION: We present a case of a 48-year old male who presented to the emergency department with altered mental status. Magnetic resonance angiography (MRA) findings revealed an aberrant right subclavian artery (ARSA), early bifurcation of the right common carotid artery (CCA) with anomalous origin of the right vertebral artery (VA) from the right common carotid artery bifurcation, anomalous left vertebral artery originating from the aortic arch, and absent left common carotid artery with independent origins of the left external carotid artery (ECA) and internal carotid artery (ICA). No other abnormalities were identified, and the patient demonstrated no symptoms attributable to his vascular anomalies. CONCLUSION: To our knowledge, this unique combination of anomalies has never been reported in the literature. With an understanding of embryological pathways, even exceedingly rare anomalies like this one can be explained.

Persistent trigeminal artery as a rare cause of vertebrobasilar insufficiency.

The persistent trigeminal artery (PTA) is the most common foetal carotid-basilar anastomosis which may persist into adult life. In the literature there are numerous papers referring to the anatomical characteristics of this anomalous vessel. In the majority of cases PTA is an incidental finding and its clinical significance has been debated. Some authors describe the coincidence of PTA with various clinical syndromes. However, there are few reports linking PTA with the symptoms of vertebrobasilar insufficiency. We present a patient with a 3-year history of recurrent dizziness and impaired vision, precipitated by physical activity, in whom neuroimaging techniques revealed a left PTA. In our case the occurrence of PTA might have been related to the clinical manifestation and the potential mechanism will be discussed.

Persistent Primitive Hypoglossal Artery with Ipsilateral Symptomatic Carotid Artery Stenosis and Cerebral Aneurysm.

OBJECTIVE: Persistent primitive hypoglossal artery (PPHA) is a rare type of persistent carotid-basilar anastomosis sometimes associated with other vascular lesions. We treated an extremely rare case of PPHA with concomitant ipsilateral symptomatic cervical internal carotid artery (ICA) stenosis and unruptured aneurysm. CASE PRESENTATION: A 67-year-old woman visited our institution with acute onset of diplopia. Magnetic resonance imaging revealed multiple acute infarctions in the right anterior and posterior circulations. Digital subtraction angiography demonstrated the right PPHA concomitant with ipsilateral cervical ICA stenosis and an unruptured ICA aneurysm with maximum diameter of 8 mm. The multiple infarctions were considered to result from artery-to-artery embolism due to microthrombi from the ICA plaque passed along the PPHA, so carotid endarterectomy was performed as the first step with preoperative modified Rankin Scale (mRS) grade 1. During the operation, the patient had impaired ICA perfusion due to internal shunt catheter migration into the PPHA followed by acute infarction in the right hemisphere causing mild left hemiparesis. The patient was transferred to the rehabilitation hospital with mRS grade 3. After 3 months of rehabilitation, the patient recovered to mRS grade 1 and clipping surgery for the unruptured right ICA aneurysm was performed as the second step with uneventful postoperative course. CONCLUSION: The treatment strategy should be carefully considered depending on the specific blood circulation for such cases of PPHA with unique vasculature.

Retroesophageal right subclavian artery associated with a bicarotid trunk and an ectopic origin of vertebral arteries.

A rare branching pattern of the aortic arch in a female cadaver is reported. An aberrant right subclavian artery originated from the distal part of the aortic arch and following a retroesophageal course was recognized. Next to it, from the left to the right, the left subclavian artery and a short bicarotid trunk originating the left and the right common carotid artery were recognized. An unusual origin of the vertebral arteries was also identified. The left vertebral artery originated directly from the aortic arch, whereas the right vertebral artery originated directly from the right common carotid artery. Retroesophageal right subclavian artery associated with a bicarotid trunk and ectopic origin of vertebral arteries represents an exceptional and noteworthy case.

Carotid web prevalence in a large hospital-based cohort and its association with ischemic stroke.

Carotid artery webs are shelf-like protrusions of intimal fibrous tissue arising from the posterior wall of the carotid bulb, found to have a 2.3% prevalence in the United States. Previous studies have demonstrated its association with ipsilateral anterior circulation stroke. The aim of this study is to assess the prevalence of carotid webs in the largest US epidemiologic study to date, and to further characterize the clinical features of carotid web patients. We assembled a cohort of 1467 adult patients with CT angiogram neck from January 1, 2011 to January 1, 2017. CT angiograms were reviewed for diagnosis of carotid web. Demographic and clinical details of web patients were obtained. Differences in demographics and CT angiogram indication between patients with and without carotid web were assessed using appropriate statistical tests. Twenty-four (24/1467 = 1.6%) carotid web patients were identified (mean age: 63 years; 62.5% female; 50% African American). Twelve (12/24 = 50%) had ipsilateral anterior circulation stroke. Of them, 8 were deemed cryptogenic. Four (4/24 = 16.7%) web patients had at least one recurrent stroke in the ipsilateral anterior circulation. One case was reported on the radiology report at the time the study was initially performed. This study confirms a prevalence of 1.6% in our urban, North American cohort. Among carotid web patients, there was a high incidence of ipsilateral anterior circulation stroke, the majority of which were classified as cryptogenic. This study affirms the importance of the diagnosis of carotid web, especially in cryptogenic stroke patients, as a potential unrecognized stroke risk factor.

Association between C-reactive protein and carotid plaque in mild-to-moderate idiopathic pulmonary fibrosis.

An association between C-reactive protein (CRP) levels and carotid plaque has never been investigated in idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the extent of carotid atherosclerosis in mild-to-moderate IPF and to assess its relationship to serum CRP. This observational retrospective case-control study included 60 consecutive IPF patients (73.8 ± 6.6 years, 45 males) and 60 matched controls, examined between Sep 2017 and Jan 2019. All patients underwent CRP assessment and a carotid Doppler ultrasonography. CRP levels were significantly higher in IPF patients than controls (0.2 ± 0.09 mg/dl vs 0.09 ± 0.04 mg/dl, p < 0.0001). A total of 46 plaques were detected, with higher prevalence in IPF patients than controls (38 vs 8, p < 0.0001). On univariate logistic regression the main variables independently associated with carotid plaque were: age (HR 1.09, 95% CI 1.03-1.16, p = 0.006), hypertension duration (HR 1.05, 95% CI 1.01-1.09, p = 0.01), diabetes duration (HR 1.09, 95% CI 1.01-1.18, p = 0.03), LDL-cholesterol (HR 1.07, 95% CI 1.04-1.10, p < 0.0001) and finally CRP levels (HR 1.73, 95% CI 0.59-5.00, p < 0.0001). Multivariate logistic regression analysis revealed that LDL-cholesterol (HR 1.05, 95% CI 1.01-1.08, p = 0.009) and CRP levels (HR 1.43, 95% CI 0.39-5.19, p < 0.0001) retained statistical significance. Common carotid artery-intima media thickness was significantly correlated with CRP levels in IPF patients (r = 0.86). SerumCRP might represent both an early marker and a potential therapeutic target for carotid atherosclerosis in mild-to-moderate IPF.

Medial type persistent trigeminal artery associated with a saccular aneurysm at its trunk.

There are four types of fetal anastomosis between the carotid and vertebrobasilar arteries at 5 weeks gestation; from caudal to cranial position, these involve the proatlantal intersegmental, hypoglossal, otic, and trigeminal arteries. Excluding otic artery, these arteries may persist rarely. Persistent trigeminal artery (PTA) is the most common carotid-vertebrobasilar anastomosis, and the medial type (intrasellar) PTA is quite rare, accounting for approximately 10% of all PTA cases. An aneurysm is occasionally found at the origin of the PTA. Rarely, an aneurysm arises at the trunk of the PTA. Using magnetic resonance angiography, we identified a case of medial type PTA with an unruptured saccular aneurysm at its trunk.

Carotid artery tortuosity may pose a problem during insertion of the tunneled catheter for hemodialysis.

Tortuosity of the carotid artery is usually an asymptomatic vascular abnormality and is discovered accidentally during cerebral angiography. These vascular changes may aggravate surgical procedures in the neck region. We described a technique of permanent catheter insertion in patients with renal graft failure in whom renal replacement therapy was necessary. Severe tortuosity of cervical arteries may make this procedure more difficult, necessitating a special technique, that is, full image monitoring.

Transcirculation approach for stent-assisted coiling of intracranial aneurysms: a multicenter study.

BACKGROUND: The transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches. OBJECTIVE: To describe a multicenter experience using the TCA for SAC. METHODS: A multicenter, retrospective study (2016-2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0-2) RESULTS: Twenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery-fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery-posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption. CONCLUSIONS: The TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes.

Prevalence and morphological changes of carotid kinking and coiling in growth: an echo-color Doppler study of 2856 subjects between aged 0 to 96 years.

Extracranial internal carotid artery (EICA) kinking and coiling are the most frequently reported carotid anomalies in the literature. Embryogenic and acquired causes for such anomalies have been postulated but the prevalence of kinking and coiling has not been well characterized across age categories. The aim of this study is to evaluate the prevalence of EICA coiling and kinking among different age groups to better understand its potential causes and changes during the course of life. A total of 2856 subjects aged 0 to 96 years were studied by echo-color Doppler (ECD). Morphology and anatomical anomalies of the EICA were assessed. Patients with anatomical anomalies were stratified by age groups and the prevalence of EICA abnormalities was calculated. The maximal velocity recorded at the level of the kinking was compared with that measured in the common carotid artery and the peak systolic velocity kinking ratio (PSVKR) was calculated. A total of 284 subjects (9.94% of the sample) were found to have kinking or coiling of the EICA. The prevalence was significantly higher at the extremes of age (≤ 20 and > 60 years old, p < 0.001) supporting the hypothesis of a reduction with growth and a new increase in the elderly. PSVKR was higher in subjects with more severity kinking. This study showed a higher prevalence of EICA coiling and kinking in the very young and in the elderly. This bimodal prevalence distribution supports the hypothesis of a congenital anomaly that resolves with somatic growth, while advanced age with its many anatomical changes leads to its reappearance or worsening. Studies with longitudinal follow-up and paired observation are required to support this hypothesis.

Artéria trigeminal e aneurisma segmentar da artéria carótida associadas a hemorragia subaracnóide / Trigeminal artery and segmental aneurysm of the carotid artery associated with subarachnoid hemorrhage

A persistência e a falha da involução das comunicações embrionárias entre a circulação cerebral anterior e posterior contribuem para anomalias vasculares em adultos. Esta variação é comumente detectada de forma incidental, causando sintomas muito raramente. Sua proximidade com os nervos oculomotor, troclear e abducente podem levar a paresia muscular ocular. Em alguns casos pode causar tinnitus pulsátil e ao espasmo de hemiface. Muitos casos de artéria trigeminal foram relatados como associados a aneurismas intracranianos.

The persistence and failure of the involution of embryonic communications between the anterior and posterior cerebral circulation contribute to vascular anomalies in adults. This variation is commonly detected incidentally, rarely causing symptoms. Its proximity to the oculomotor, trochlear, and abducent nerves can lead to ocular muscle paresis. Sometimes it can cause pulsatile tinnitus and hemiface spasm. Many cases of trigeminal artery have been reported to be associated with intracranial aneurysms.

Absent left common carotid artery in a right aortic arch: Separate origins of left internal and external carotid arteries from brachiocephalic artery.

We present a case of cyanotic congenital heart disease with left common carotid artery agenesis in the setting of the right aortic arch highlighting the potential implications in management.

MN1 C-terminal truncation syndrome is a novel neurodevelopmental and craniofacial disorder with partial rhombencephalosynapsis.

MN1 encodes a transcriptional co-regulator without homology to other proteins, previously implicated in acute myeloid leukaemia and development of the palate. Large deletions encompassing MN1 have been reported in individuals with variable neurodevelopmental anomalies and non-specific facial features. We identified a cluster of de novo truncating mutations in MN1 in a cohort of 23 individuals with strikingly similar dysmorphic facial features, especially midface hypoplasia, and intellectual disability with severe expressive language delay. Imaging revealed an atypical form of rhombencephalosynapsis, a distinctive brain malformation characterized by partial or complete loss of the cerebellar vermis with fusion of the cerebellar hemispheres, in 8/10 individuals. Rhombencephalosynapsis has no previously known definitive genetic or environmental causes. Other frequent features included perisylvian polymicrogyria, abnormal posterior clinoid processes and persistent trigeminal artery. MN1 is encoded by only two exons. All mutations, including the recurrent variant p.Arg1295* observed in 8/21 probands, fall in the terminal exon or the extreme 3' region of exon 1, and are therefore predicted to result in escape from nonsense-mediated mRNA decay. This was confirmed in fibroblasts from three individuals. We propose that the condition described here, MN1 C-terminal truncation (MCTT) syndrome, is not due to MN1 haploinsufficiency but rather is the result of dominantly acting C-terminally truncated MN1 protein. Our data show that MN1 plays a critical role in human craniofacial and brain development, and opens the door to understanding the biological mechanisms underlying rhombencephalosynapsis.