Internal Carotid Artery In Relation Research Articles

Feasibility of Preoperative Magnetic Resonance Angiography/Black-Blood Magnetic Resonance Imaging/Computed Tomography Fusion Imaging Without Contrast Agent for Carotid Endarterectomy

Preoperative identification of the carotid bifurcation (CB) location and plaque and stenosis distal end of the cervical internal carotid artery in relation to bony structures is essential for carotid endarterectomy (CEA). However, for patients with contrast contraindications, cervical 3-dimensional computed tomography angiography (3D-CTA) is unavailable. In this study, we created fusion images of magnetic resonance angiography (MRA), black-blood (BB) magnetic resonance imaging (MRI), and CT to determine if these noncontrast agent images are superior to 3D-CTA for preoperative CEA planning. The fusion images showed vascular structures obtained by MRA, plaque observed by BB-MRI, and bone structures shown by CT. Spatial localization accuracy was verified by directly overlaying contrast-enhanced 3D-CTA images on the fusion images. We validated this technique in 50 patients with unilateral ICA stenosis, 28 of whom underwent CEA. The 2D-distance CB MRA-CTA (the 2D distance difference between CB MRA and CB CTA perpendicular to the long axis of the carotid artery) was measured. We also compared the findings of the fusion image regarding the CB location and plaque distal end with the operative findings. The median 2D distance CB MRA-CTA was 1mm. CB MRA was located distal and proximal to CB CTA in 21and 29 patients, respectively. The CB location and fusion-image plaque were consistent with the intraoperative findings in all CEA patients. Fusion images created from MRA, BB-MRI, and noncontrast CT were feasible as an alternative to 3D-CTA for patients with contrast contraindications.

Magnetic resonance angiographic study of variations in course of paraclival and parasellar internal carotid artery in relation to expanded endonasal endoscopic approaches.

To study the variations in the course of the paraclival and parasellar carotid arteries in normal subjects using magnetic resonance angiography as is relevant from an endoscopic endonasal perspective. Two hundred MR angiographies of normal subjects were analyzed in a prospective study. The intercarotid distances were measured at fixed points along the paraclival and parasellar segments of the internal carotid artery. The intercarotid spaces thus obtained were categorized into trapezoid, square and hourglass shapes. The angle between the posterior ascending vertical and horizontal bend of the parasellar ICA was also measured and analyzed. The trapezoid shape of intercarotid space is the most common (52.5%), followed by the square (35%) and the hourglass (12.5%) shaped spaces. Angle of < 80° between the posterior ascending vertical and horizontal bend of the parasellar ICA was found in 39% of subjects, angle between 80° and 100° was found in 9% subjects, angle > 100° was found in 43% while asymmetric angles on the two sides was found in 9% of subjects. A thorough understanding of the course of the ICA is important in planning the approach and preventing injury to the ICA.

Pathogenesis regarding development and structure of unstable atherosclerotic plaque in internal carotid artery in relation to high risk factors of an ischaemic stroke. Current status of knowledge

Worldwide, stroke is the second leading cause of death and a major cause of disability . However, the mortality of stroke differs between countries and geographical regions. In high-income countries, i.e. in the United States, stroke has fallen from the third to the fourth leading cause of death. The risk for ischaemic stroke increases with the degree of internal carotid artery stenosis. 70–99% carotid artery stenosis (according to NASCET) in symptomatic patients is an indication for a vascular intervention since this group will achieve significant benefits from surgical treatment. Asymptomatic patients with 60–99% (according to NASCET) carotid artery stenosis may also benefit from surgical procedures when at least one-factor conditioning a high risk of ischaemic stroke incidence exists. These factors may include morphological structure features of atherosclerotic plaque described in imaging examinations that are indicative of its instability and specific clinical predispositions. The paper presents stages of unstable atherosclerotic plaque development and features of its morphological structure that may significantly increase the risk for ischaemic stroke and compares them with current guidelines: Management of Atherosclerotic Carotid and Vertebral Artery Disease: 2017 Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS).

Anatomical nuances of the internal carotid artery in relation to the quadrangular space

OBJECTIVE The aim of this study was to evaluate the anatomical variations of the internal carotid artery (ICA) in relation to the quadrangular space (QS) and to propose a classification system based on the results. METHODS A total of 44 human cadaveric specimens were dissected endonasally under direct endoscopic visualization. During the dissection, the anatomical variations of the ICA and their relationship with the QS were noted. RESULTS The space between the paraclival ICAs (i.e., intercarotid space) can be classified as 1 of 3 different shapes (i.e., trapezoid, square, or hourglass) based on the trajectory of the ICAs. The ICA trajectories also directly influence the volumetric area of the QS. Based on its geometry, the QS was classified as one of the following: 1) Type A has the smallest QS area and is associated with a trapezoid intercarotid space, 2) Type B corresponds to the expected QS area (not minimized or enlarged) and is associated with a square intercarotid space, and 3) Type C has the largest QS area and is associated with an hourglass intercarotid space. CONCLUSIONS The different trajectories of the ICAs can modify the area of the QS and may be an essential parameter to consider for preoperative planning and defining the most appropriate corridor to reach Meckel's cave. In addition, ICA trajectories should be considered prior to surgery to avoid injuring the vessels.

Rare cause of recurrent fainting – multiple kinking and brachiocephalic origin of the left common carotid artery

1. Paulsen F, Tillmann B, Christofides C, Richter W, Koebke J. Curving and looping of the internal carotid artery in relation to the pharynx: frequency, embryology and clinical implications. J Anat. 2000; 197: 373–381. Google Scholar

Aberrations of the Cervical Carotid Artery Which May Be Dangerous in Pharyngeal Surgery—A Computed Tomographic Study

Background: There are recognised variations in the anatomical course of the cervical portion of the internal carotid artery. An aberrant vessel with direct contact to the pharyngeal wall could easily be injured during pharyngeal surgery or may appear as a pharyngeal pseudo mass. Previous anatomical studies predominantly involved older patients. The prevalence of such variations which are at risk of injury during pharyngeal surgery has thus not been established in a general patient population. Material and Methods: The course of the internal carotid artery in relation to the oro and hypopharyngeal walls was retrospectively evaluated bilaterally by simple visual inspection and measurement of the smallest distance between the respective vessels and the adjacent mucosal surface of the pharyngeal wall in 138 consecutive contrast-enhanced computed tomography scans of the neck. Results: 11/138 (7.9%) of patients demonstrated relevant cervical carotid artery aberrations, comprising medial kinking of a vessel with asymmetry of the adjacent pharyngeal lumen and/or an intimate submucous course in the pharyngeal wall with no identifiable separating fat plane. This prevalence increased with age. Simple visual inspection correlated well with the measurement of the smallest distance between an artery and the pharyngeal wall, which was statistically significant (p Conclusions: The prevalence of about 8% in a general patient population is higher than previously recorded in anatomical studies. Prevalence increases with age. Otorhinolaryngologists should be aware of such variation as a risk factor for haemorrhagic complications during pharyngeal surgery and as a differential diagnosis of pharyngeal mass lesions, especially in older patients. Modern contrast-enhanced CT allows identification and characterisation of any surgically relevant variant vascular anatomy in the pre-operative work-up.

Curving and looping of the internal carotid artery in relation to the pharynx: frequency, embryology and clinical implications

Variations of the course of the internal carotid artery in the parapharyngeal space and their frequency were studied in order to determine possible risks for acute haemorrhage during pharyngeal surgery and traumatic events, as well as their possible relevance to cerebrovascular disease. The course of the internal carotid artery showed no curvature in 191 cases, but in 74 cases it had a medial, lateral or ventrocaudal curve, and 17 preparations showed kinking (12) or coiling (5) out of a total of 265 dissected carotid sheaths and 17 corrosion vascular casts. In 6 cases of kinking and 2 of coiling, the internal carotid artery was located in direct contact with the tonsillar fossa. No significant sex differences were found. Variations of the internal carotid artery leading to direct contact with the pharyngeal wall are likely to be of great clinical relevance in view of the large number of routine procedures performed. Whereas coiling is ascribed to embryological causes, curving is related to ageing and kinking is thought to be exacerbated by arteriosclerosis or fibromuscular dysplasia with advancing age and may therefore be of significance in relation to the occurrence of cerebrovascular symptoms.

Application of combined three-dimensional bone and soft tissue model: A case report

This article describes a new application in three-dimensional modelling. By adding the contours of important soft tissue structures to the bone contours, it is possible to produce a combined bone and soft tissue model. The advantages of this technique are shown in a patient suffering from a parapharyngeal tumour. The model not only enabled the precise localisation of the tumour in relation to the surrounding bone, but also identified important structures like the internal carotid artery in relation to the tumour.

91294607 Pulsatility index in internal carotid artery in relation to transdermal oestradiol and time since menopause

91294607 Pulsatility index in internal carotid artery in relation to transdermal oestradiol and time since menopause

Pulsatility Index in Internal Carotid Artery in Relation to Transdermal Oestradiol and Time Since Menopause

Pulsatility Index in Internal Carotid Artery in Relation to Transdermal Oestradiol and Time Since Menopause

Pulsatility index in internal carotid artery in relation to transdermal oestradiol and time since menopause

The protection afforded by postmenopausal oestrogen replacement against cardiovascular disease is not fully explained by changes in plasma lipoproteins. To investigate the effect of oestrogen on arterial tone, doppler ultrasound was used to assess blood flow characteristics in the internal carotid arteries of 12 postmenopausal women. Patients were studied pretreatment and at weeks 4, 6, 9, and 22 of therapy with transdermal oestradiol 50 μg/day. The pulsatility index (PI), which is thought to represent impedance to blood flow distal to the point of sampling, was measured from the flow velocity waveform. 11 of the 12 patients were within 5 years of menopause; 1 was 8 years postmenopausal but had experienced bleeding 4 years after menopause. In the 11 women there was a highly significant correlation (r=0·77) between time since menopause and baseline PI. A similar correlation (r=0·74) was observed when the episode of postmenopausal bleeding was redefined as time of menopause in the twelfth patient. For all 12 patients, there was a significant negative correlation (r=-0·70) between change in PI during transdermal oestradiol therapy and mean of baseline plus week 22 PI value. For all correlations between changes in PI and time since menopause, the longer the time the greater the fall in PI. These results, and previous observations of a reduction in uterine artery PI with oestradiol treatment, suggest that oestrogen has a generalised effect on the arterial system.

Cephalic arterial pattern in New World edentates and Old World pangolins with special reference to their phylogenetic relationships and taxonomy.

The cephalic arterial pattern in edentates and pangolins is described on the basis of 9 corrosion specimens, representing all the classical superfamilies, with special reference to their phylogenetic relationship and taxonomy. In this respect, the importance of the manner in which the external carotid artery system annexes the stepedial area of supply and of the course of the internal carotid artery in relation to the tympanic cavity is emphasized. The investigation does not indicate any special relationship between the New World edentates and the Old World pangolins, whereas the marked difference in the course of the internal carotid artery in recent edentates stresses the independent development of the South American anteaters compared with that of the two other edentate groups (armadillos and tree sloths). Most probably the edentates were divided very early into two main lines which have evolved independently since the early Tertiary, i.e. one for the anteaters and one for the tree sloths and armadillos, indicating a probable subdivision of the true edentates into two suborders. This subdivision is markedly different from the classical two-fold division of the edentates.

Application of Stereotactic Principles to the Treatment of Trigeminal Neuralgia

The application of neuroanatomical and neurophysiological principles to the functional surgery of the trigeminal nerve is discussed. Particular attention has been directed toward correlating the three-dimensional anatomical features of the trigeminal nerve and the surrounding structures to the two-dimensional radiograph of this same region. In this regard, 20 trigeminal nerves, including the surrounding neurovascular structures from 10 cadaver sphenoid blocks, were examined. Measurements of the third, fourth and sixth cranial nerves in relation to the profile of the clivus were made from lateral radiographs of the sphenoid blocks. The position of the internal carotid artery in relation to these structures was also noted. These neurovascular relationships are of clinical importance when using the percutaneous thermocoagulation technique for the treatment of trigeminal neuralgia.