[Dynamic functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Dinamicheskaya funktsional'naya otsenka patologicheskikh izvitostei vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom. Klinicheskii sluchai.

A personalized approach with attention to anamnesis and specific symptoms is necessary in patients with internal carotid artery tortuosity. Neuroimaging (especially before elective surgery) or functional stress tests following ultrasound of supra-aortic vessels may be necessary depending on medical history and complaints. In addition to standard Doppler ultrasound, these patients should undergo rotational and orthostatic transformation tests. We analyze changes in shape and hemodynamic parameters within the tortuosity area in various body positions. This is especially valuable for patients with concomitant carotid artery stenosis. The article presents a clinical case illustrating the importance of such approach.

[Functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Vazhnost' dinamicheskoi funktsional'noi otsenki patologicheskoi izvitosti vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom.

The review is devoted to diagnosis and treatment of internal carotid artery tortuosity. The authors consider modern classification, epidemiology and diagnostic options using neuroimaging or ultrasound-assisted functional stress tests depending on medical history and complaints. In addition to standard Doppler ultrasound, rotational and orthostatic tests are advisable due to possible changes of local shape and hemodynamic parameters following body position changes, especially in patients with concomitant atherosclerotic stenosis. Thus, a personalized approach is especially important for treatment and diagnostics of internal carotid artery tortuosity.

Ischemic stroke due to stylocarotid artery syndrome: a case report and review.

Stylocarotid artery syndrome (SAS) is a rare variant of Eagle's syndrome that may lead to transient ischemic attack or stroke. The underlying pathophysiological mechanism involves compression of the internal carotid artery by an elongated styloid process (ESP), potentially resulting in vascular occlusion or dissection. An ESP exceeding 2.5 cm is deemed elongated, with a length of 3.0 cm considered clinically significant. Although the prevalence of ESP ranges from 4.0% to 7.3%, symptomatic cases are rare; symptoms are present in only approximately 4.0% of individuals with an ESP. Unlike the typical symptoms of Eagle's syndrome, SAS may not cause pharyngeal discomfort, the sensation of a foreign body in the throat, dysphagia, or facial pain. This absence of characteristic symptoms as well as the development of central nervous system symptoms often leads patients to seek care from neurologists instead of otolaryngologists, increasing the likelihood of misdiagnosis or underdiagnosis. We herein report a unique case of ischemic stroke caused by SAS and present a literature review on cases of SAS-associated ischemic stroke published in the past decade. The reporting of this study conforms to the CARE guidelines.

[Internal Carotid Artery:Development and Anomalies].

This chapter outlines the cerebrovascular developmental anatomy with emphasis on the internal carotid artery(ICA), which is important for optimal endovascular treatment of cerebrovascular system disorders. Gene expression, neural crest cells, and pharyngeal arches play key roles in the embryonic development of the carotid arteries. Evolutionary inheritance in vertebrates contributes to the formation, regression, and segmental structure of these arteries. We present examples of current mutations with regard to their segmental nature; ICA mutations are discussed primarily with regard to their developmental origin from the first to third pharyngeal arches and the role of the ductus caroticus. This comprehensive review highlights the importance of understanding the developmental and anatomical nuances of the ICA to aid with accurate diagnosis and management of vascular anomalies in the clinical setting. We have focused on the complexity associated with ICA mutations, particularly those associated with the third pharyngeal arch and the need for a solid foundation of developmental and anatomical knowledge to accurately identify and interpret their significance in the adult phenotype.

Replaced posterior cerebral artery.

PURPOSE: Replaced posterior cerebral artery (PCA), defined as a hyperplastic anterior choroidal artery (AChA) supplying all branches of the PCA, is an extremely rare anatomical variation. To the best of our knowledge, there are only a few reports of replaced PCA. METHODS: Herein, we report a case of replaced PCA diagnosed by digital subtraction angiography. RESULTS: A 76-year-old woman visited a neurosurgical clinic because of headache and vertigo. Magnetic resonance imaging and magnetic resonance angiography incidentally revealed a left internal carotid artery aneurysm. She was referred to our hospital for further examination and treatment of the unruptured intracranial aneurysm. Left internal carotid angiography revealed a paraclinoid aneurysm. We also incidentally found an anomalous hyperplastic AChA distal to the aneurysm. This hyperplastic AChA supplied not only the AChA territory but also the entire PCA territory. No vessels that could be a normal AChA or posterior communicating artery were identified along the left internal carotid artery. Vertebral angiography demonstrated that the left PCA was not visualized. With these findings, we diagnosed anomalous hyperplastic AChoA in this case as replaced PCA. CONCLUSION: Careful imaging assessment is important to identify replaced PCA. Both direct findings of a hyperplastic AChA course and perfusion territory and indirect findings of the absence of the original PCA are useful in the diagnosis of replaced PCA.

Left anterior cerebral artery arising from a right internal carotid artery: a rare case of carotid-anterior cerebral artery anastomosis.

Carotid-anterior cerebral artery anastomosis (carotid-ACA anastomosis) is described as infrequent vascular connections between the pre-ophthalmic segment of the internal carotid artery (ICA) and the A1 segment of the anterior cerebral artery (ACA). The embryological origin of these variant is still unclear and they are often associated to other vascular anomalies of the circle of Willis, as well as to the presence of aneurysms. Carotid-ACA anastomosis is often right-sided although left and bilateral cases have also been described. We report a rare case by MR angiography of a carotid-ACA anastomosis in which the abnormal vessel arises from the right ICA and takes an infraoptic course to join the A2 segment of the contralateral ACA, making this vascular anomaly function as a 'left ACA with an origin at the right ICA'. The A1 segment of the left ACA is absent and both A2 segments of the ACAs present fenestration. To our knowledge, no similar cases have been reported in English literature so far.

Anomalous origin of the temporopolar artery from the internal carotid artery and aneurysms at the temporopolar and internal carotid arteries: a very rare case report.

The temporopolar artery (TPA) originates directly from the sphenoidal segment of the middle cerebral artery (MCA). Its originating from the M1 segment of the MCA as a branch of the anterior temporal artery is not uncommon. However, internal carotid artery origination is a very rare variation of the TPA. Here, we report a very rare case of the variant origin of the TPA and the presence of saccular aneurysm at this origin.

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.

Diagnostic Yield of Bone Window Computed Tomography and Cerebral Angiography Testing Congenital Bilateral Hypoplasia of the Internal Carotid Artery.

We herein report a case of congenital bilateral hypoplasia of the internal carotid artery (ICA) that was diagnosed by bone window computed tomography (CT) and cerebral angiography. A 23-year-old woman presented with left dominant quadriplegia. Brain magnetic resonance imaging showed not only massive infarcts in the anterior circulation but also poor depiction of the bilateral ICAs. Bilateral carotid canals on bone window CT suggested hypoplasia. Cerebral angiography revealed narrowing of each ICA above its bifurcation, and the blood supply to the intercranial carotid systems developed from the vertebrobasilar system through the posterior communicating arteries and posterior cerebral arteries. We diagnosed the patient with congenital bilateral hypoplasia of the ICA based on bone CT and cerebral angiography findings. Performing both bone window CT and cerebral angiography can facilitate the diagnosis of congenital hypoplasia of the ICA.

Case of Amaurosis Fugax in the Setting of a Persistent Primitive Hypoglossal Artery Requiring Carotid Endarterectomy with Regional Anesthesia.

BACKGROUND A persistent primitive hypoglossal artery (PPHA) is a rare congenital anomaly leading to persistent carotid-basilar anastomosis. This is a report of an 83-year-old man with a PPHA presenting with amaurosis fugax of the left eye requiring carotid endarterectomy under regional anesthesia. CASE REPORT An 83-year-old man presented with 2 weeks of intermittent self-resolving visual disturbances, followed by an episode of left eye amaurosis fugax. The patient had been referred to the hospital for further investigation of symptoms 1 day following the amaurosis fugax event. Carotid Doppler ultrasound demonstrated a greater than 90% stenosis of the left internal carotid artery. Computed tomography carotid and Circle of Willis angiography confirmed a mixed, ulcerated plaque and revealed a persistent left hypoglossal artery originating from the left internal carotid artery and continuing as the basilar artery. On day 3 of admission, left carotid endarterectomy was performed under conscious sedation and regional anesthesia to permit continuous monitoring of neurological status and avoid the need for intraoperative shunting. "Permissive hypertension" by targeting a systolic blood pressure of 190 to 200 mmHg was sought for the duration of clamp time. There was no deterioration of neurological function during clamping of the carotid vessels. The patient recovered well and was discharged 2 days after surgery, with no residual neurology. CONCLUSIONS This report has presented a rare case of PPHA to highlight awareness of this congenital vascular anomaly when undertaking carotid endarterectomy.

ICA agenesis with transcavernous anastomosis: a systematic review.

PURPOSE: To present two cases of Internal Carotid Artery (ICA) agenesis and conduct a systematic review to assess for associations with other anomalies and intracranial aneurysms. METHODOLOGY: We performed a retrospective review of published cases of patients with ICA agenesis with intercavernous anastomosis in MEDLINE database on August 2022 using search terms "internal carotid artery", "agenesis" and "transcavernous anastomosis". We also included two cases of ICA agenesis with type D collateral that we encountered. RESULTS: Total of 46 studies that included 48 patients and two of our cases resulted in 50 patients. Only 70% of studies reported the location of a collateral vessel of which more than two-thirds were on the floor of sella. More than half of the vessels connected cavernous segments of ICA. A1 segment ipsilateral to the side of ICA agenesis was absent in most of the cases but was not true for all cases. Aneurysm was seen in more than one-quarter of the patients. It can also mimic microadenoma as in prior reported cases as well as in one of our cases. CONCLUSION: ICA agenesis with type D collateral is a rare anomaly but clinically relevant due to the increased risk of an aneurysm or mimic microadenoma or false alarm for occlusion of ICA but knowledge of this rare variant can help in better management of these patients.

Proposed new classification for internal carotid artery segmental agenesis based on embryologic and angiographic correlation.

BACKGROUND AND PURPOSE: Internal carotid artery (ICA) agenesis is a rare anatomical variant that can involve different segments of the ICA. Although many authors proposed their own classifications of this variant basing on different criteria, none of these allows to include all the cases described in the literature. The aim of the authors is to propose a new classification that allows to include all cases of ICA agenesis described until now. MATERIALS AND METHODS: The study is based on the review of all the cases of ICA agenesis described in the literature and of the classifications already proposed. After the analysis of these cases, we looked for the limits of each classification to elaborate a new more complete one. RESULTS: We found 228 cases of ICA agenesis. Among them 40 were not includible in the existing classifications. For this reason, we proposed a new classification based on the type of flow compensation and on the embryological events that determine the different variants. The flow is compensated in Type I by the Circle of Willis; in Type II by the non-regression of an embryonic artery; in Type III by the presence of an arterio-arterial anastomosis and in Type IV by external-internal carotid arteries anastomoses. CONCLUSION: After the literature review, we proposed a new comprehensive classification based on the detailed analysis of arterial embryology. Even if all the embryological details that determine this complex variant are not completely understood yet, this classification allows to include all the cases described in literature.

Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion.

PURPOSE: Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints. METHODS: We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient. RESULTS: CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered. CONCLUSIONS: This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

Developed Circuminfundibular Anastomosis Associated with Vascular Abnormalities.

We report a 74-year-old male patient who presented with left hemiplegia and disturbance of consciousness. Computed tomography revealed diffuse subarachnoid hemorrhage, which was prominent in the right Sylvian and basal cisterns. Digital subtraction angiography revealed absence of the C2 segment of the right internal carotid artery (ICA) and a significantly developed circuminfundibular anastomosis. Occlusion of the bilateral vertebral arteries (VAs) was also seen. The upper basilar artery was supplied by the circuminfundibular anastomosis and collaterals from the VAs. Since the source of bleeding was unclear, the patient was treated conservatively. Circuminfundibular anastomosis is a potential anastomosis around the pituitary stalk. It is formed by the superior hypophyseal arteries, prechiasmal arteries, and infundibular arteries bilaterally. Agenesis of the contralateral ICA often leads to development of ICA-ICA anastomoses. In this case, the anastomosis developed due to agenesis of the C2 segment of the right ICA and occlusion of the bilateral VAs.