A retropharyngeal internal carotid artery is considered a rare anatomic variant with clinical implications. We present a 73-year-old woman with asymptomatic left carotid stenosis, in whom we elected to proceed with medical treatment.
Anesthesia providers and perioperative clinicians can take simple actions to rule out a retropharyngeal carotid artery. First, ask the patient about fullness or a pulsatile mass in the back of the mouth, as well as difficulty swallowing.
As blood traverses the aortic arch, it reaches the second major branch of the aorta, the left common carotid artery. The common carotids then traverse up into the neck through the carotid sheath, where they finally bifurcate into the external and internal carotid arteries at the level of the carotid sinus and the fourth cervical vertebra (C4).
Occlusion of the internal carotid artery (ICA) results in collateral formation via the external carotid artery (ECA). Contributed by Scott Dulebohn, MD Figure An example of collateralization in a patient with left common carotid artery (CCA) occlusion. The left CCA is occluded (black arrow).
An anomalous course of the carotid artery in the retropharyngeal space is an unusual finding that poses a risk of vascular injury during pharyngeal surgery and intubation. 1 2 Such an anomaly may be congenital (due to incomplete descent of the third aortic arch) or acquired (due to atherosclerosis and hypertension).
The internal carotid artery runs upward through the neck and enters the skull through the carotid canal, located in the petrous portion of the temporal bone just superior to the jugular fossa. Within the anterior portion of the canal, only thin bone separates the artery from the cochlea and the trigeminal ganglion.
Carotid artery disease occurs when fatty deposits (plaques) clog the blood vessels that deliver blood to your brain and head (carotid arteries). The blockage increases your risk of stroke, a medical emergency that occurs when the blood supply to the brain is interrupted or seriously reduced.
The internal carotid artery, being one of the most clinically relevant and vital arteries, supplies oxygenated blood to crucial structures such as the brain and eyes.
Internal carotid arteries The internal carotid artery is one of two branches of the common carotid artery. It is responsible for supplying a large portion of the anterior and middle parts of the brain.
The internal carotid artery is a major branch of the common carotid artery, supplying several parts of the head with blood, the most important one being the brain. There are two internal carotid arteries in total, one on each side of the neck.
Carotid endarterectomy, the most common treatment for severe carotid artery disease. After making an incision along the front of your neck, the surgeon opens the affected carotid artery and removes the plaques. The artery is repaired with either stitches or a graft.
Surgery is the best option for symptomatic patients with 70% to 99% blockage in the carotid artery. However, it can also be considered for patients with 50% to 69% blockage. Doctors agree that surgery is the most effective option for patients with moderate to severe carotid stenosis.
If the narrowing of the carotid arteries becomes severe enough that blood flow is blocked, it can cause a stroke. If a piece of plaque breaks off it can also block blood flow to the brain. This too can cause a stroke.
What Are the Symptoms of Carotid Artery Disease?Sudden loss of vision, blurred vision, or difficulty in seeing out of one or both eyes.Weakness, tingling, or numbness on one side of the face, one side of the body, or in one arm or leg.Sudden difficulty in walking, loss of balance, lack of coordination.More items...•
The axial CT showed left internal carotid artery in a retropharyngeal location. An anomalous course of the carotid artery in the retropharyngeal space is an unusual finding that poses a risk of vascular injury during pharyngeal surgery and intubation. Such an anomaly may be congenital (incomplete descent of the third aortic arch) and may be more pronounced in older patients secondary to atherosclerosis and hypertension as occurred in our case noted here.
Retropharyngeal course of the left internal carotid artery.
The carotid systems constitute the main arterial supply of the head and neck. Both common carotid arteries are deeply situated at the root of the neck, where they are only separated by the larynx and pharynx. These vessels become more superficial at the carotid triangle. At the upper border of the thyroid cartilage, usually at the disc between cervical vertebrae 3 and 4, the CCA divides into the ECA and ICA. Each ICA will extend along the side of the pharynx until it reaches the base of the skull, where it enters the carotid canal (foramen rotundum), traversing through the petrous temporal bone to the middle cranial fossa.7 Only a handful of cases have been reported on this unusual anatomic variant. Munoz et al. 1 reported a complete retropharyngeal course of carotid arteries and highlighted this anatomic variant as kissing carotids. Another report by Agrawal and Agrawal 2 presented an angiogram of the right retropharyngeal ICA. Chen et al.8 also presented 5 cases of an aberrant carotid artery, which reinforces the significance of such an anomaly in transpharyngeal interventions. An accidental finding of an aberrant carotid artery was recognized in a magnetic resonance imaging scan of the cervical spine. 9 Evaluation and ruling out any associated intracranial pathology—as for fusiform aneurysm of the posterior communicating artery—with computed tomography angiography or digital subtraction angiography should be considered.10
An illustration of the embryologic components of the 6 aortic arches. The carotid systems constitute the main arterial supply of the head and neck. Both common carotid arteries are deeply situated at the root of the neck, where they are only separated by the larynx and pharynx.
A retropharyngeal internal carotid artery is considered a rare anatomic variant with clinical implications. We present a 73-year-old woman with asymptomatic left carotid stenosis, in whom we elected to proceed with medical treatment. An evaluation of her computed tomography angiography scan revealed a retropharyngeal internal carotid artery. This case report outlines this rare entity and highlights its clinical significance.
The internal carotid artery is a major branch of the common carotid artery, supplying several parts of the head with blood, the most important one being the brain. There are two internal carotid arteries in total, one on each side of the neck. They originate from the carotid bifurcation, travel through the carotid sheath in a superior direction along the neck, and enter the skull through the external opening of carotid canal. Each artery is divided into seven segments according to the areas through which it passes. Along its course, the internal carotid artery gives rise to many branches, ultimately dividing into its two terminal ones called the anterior and middle cerebral arteries.
First things first, there are two internal carotid arteries in total, one on the right and one on the left of the neck. They both originate from their respective common carotid arteries from a point called the carotid bifurcation which is variably situated at a level between the third and fourth, or fourth and fifth cervical vertebrae (C3-C4/C4-C5).
Once the internal carotid artery has followed the previously described course and given off its eight branches, it divides into the two terminal branches described below: Anterior cerebral artery (A): it is a terminal branch of the internal carotid artery originating from the communicating segment (C7).
Each artery is divided into seven segments according to the areas through which it passes. Along its course, the internal carotid artery gives rise to many branches, ultimately dividing into its two terminal ones called the anterior and middle cerebral arteries.
They stem from several segments (C2, C4, C6, and C7) , the only exceptions being the cervical (C1), lacerum (C3), and clinoid (C5) segments do not give rise to any branches.
The clinical importance of internal carotid arteries is evident during action movies or martial arts classes where self-defense moves are performed , for example a rear naked choke or a strike to one side of the neck.
Caroticotympanic artery (C): it originates from the petrous part (C2) and travels through the tympanic cavity via the foramen within the carotid canal. It subsequently anastomoses with the anterior tympanic branch of the stylomastoid artery and the maxillary artery.
Within the cranial cavity, the two internal carotid arteries anastomose with the two vertebral arteries to form the circle of Willis, which supplies the brain with oxygenated blood. The internal carotid artery gives off its first branch, the ophthalmic artery, just distal to the cavernous sinus. The ophthalmic artery is the primary blood supply to the eye, extraocular muscles, lacrimal gland, upper nose, and parts of the forehead.[4] Following this, the internal carotid artery branches into the middle cerebral artery and the anterior cerebral artery. The middle cerebral arteries primarily supply the motor and sensory cortices for the upper limb and face, in addition to supplying Broca’s area in the dominant frontal lobe and Wernicke’s area in the dominant temporal lobe. Whereas the anterior cerebral arteries supply the region of the brain primarily responsible for motor and sensory of the lower limbs. [3]
The internal carotid and vertebral arteries. Right side. Contributed by Gray's Anatomy Plates
The carotid bifurcation is an anatomically and surgically important landmark as it involved in a variety of physiological and pathological processes. The height of the carotid bifurcation is highly variable, and extreme variations are important in determining appropriate surgical techniques such as the decision for carotid endarterectomy and carotid stenting. Additionally, the geometry of the carotid bifurcation is an important factor in blood hemodynamics and wall shear stress, which can commence or promote atherogenesis.[17] The carotid bifurcation is also the location of chemoreceptors and baroreceptors detecting blood oxygen and pressure levels to help regulate homeostasis. Surgical denervation of the carotid bifurcation can be a treatment of carotid sinus syndrome.
The internal carotid has been described by the Bouthillier classification to consist of seven distinct parts based on angiographic appearance. This classification includes the entire internal carotid artery using a numerical scale based on the direction of blood flow, and describes the segments anatomically and based on the compartments through which they travel. Each segment branches into different vessels; these branches are generally small, inconstant, and can often be not present. [5][3] The classification system goes as follows:
The internal carotid artery, being one of the most clinically relevant and vital arteries, supplies oxygenated blood to crucial structures such as the brain and eyes. The internal carotid arteries are branches of the common carotid arteries that bifurcate into the internal and external carotids at the level of the carotid sinus.[2] After this bifurcation, the internal carotids traverse through the base of the skull to reach the vital organs that they supply.
Going from inside to outside the vessel, they include the tunica intima, tunica media, and tunica adventitia. The tunica intima consists of endothelium supported by an elastic and collagenous layer. The tunica media consists of a relatively thick smooth muscle layer that is responsible for changing the diameter of the blood vessels to regulate blood flow.[3] Lastly, the most external tunica adventitia is made of collagenous and elastic tissues and serves to attach the vessel to surrounding tissues.
As blood is oxygenated in the lungs and enters the left atrium, it traverses the mitral valves into the left ventricle where it is pushed out through the aortic valve into the ascending aorta. The first major branch of the aorta that blood will circulate through is the brachiocephalic artery, which then gives off the right common carotid as it turns into the right subclavian artery. As blood traverses the aortic arch, it reaches the second major branch of the aorta, the left common carotid artery. The common carotids then traverse up into the neck through the carotid sheath, where they finally bifurcate into the external and internal carotid arteries at the level of the carotid sinus and the fourth cervical vertebra (C4). [2]
Background and purpose: Retropharyngeal carotid arteries are a clinically relevant anatomic variant. Prior studies have documented their incidence, but only a single case report has discussed the change in position of the carotid artery to and from a retropharyngeal location. The purpose of this study was to determine the prevalence of retropharyngeal carotid arteries and to evaluate the change in position of retropharyngeal carotid arteries over serial CT examinations of the neck. Materials and methods: A retrospective review of 306 CT examinations of the neck in 144 patients was performed. Patients with previous neck surgery or neck masses displacing the carotid arteries were excluded. The position of each carotid artery was evaluated on each examination. In patients with prior examinations, change or lack of change in position was recorded. The data were reviewed to assess changes in the position of the carotid arteries. Results: Of the 144 patients evaluated, 34 were excluded. The final number of examinations included in the study was 249. Sixty-three of 110 patients had at least 1 comparison study. Twenty-three retropharyngeal carotid arteries were present on the baseline examination in 17 (15.5%) of 110 patients. There was documented change to or from a retropharyngeal position in 4 (6.3%) of 63 patients with comparison studies. Conclusions: The phenomenon of migration of the carotid arteries to and from a retropharyngeal position with time is confirmed by our study. It is important for physicians to be aware of this phenomenon to avoid potential procedural complications.
Case 1 Retropharyngeal right ICA. Minimum distance to the pharyngeal wall was ~ 4.9 mm (high risk of vascular injury) with a
The retropharyngeal internal carotid artery (ICA) is a well-described arterial anomaly with important implications for patients undergoing pharyngeal approach surgical procedures. Existing clinical and imaging classification schemes for a retropharyngeal ICA take into account arterial distance to the pharyngeal mucosal wall. We describe a case of mobility of a retropharyngeal ICA between short-interval imaging studies. The possibility of respiratory variability or other etiologies causing such changes in retropharyngeal carotid position have not been described previously. Our findings suggest that imaging findings from a single study alone may not be sufficient to confidently exclude this clinically significant arterial anomaly.
Radiographic classification is based on its proximity to the pharynx and/or pathway.We present a series of three cases of retropharyngeal ICAs, our goal is to report and classify these variations.Case presentationCase 1Retropharyngeal right ICA. Minimum distance to the pharyngeal wall was ~ 4.9 mm (high risk of vascular injury) with a tortuous pathway.Case 2Bilateral retropharyngeal ICA. ICAs were in contact with the posterior pharyngeal wall (very high risk of vascular injury). The left has a kinking pathway, the right tortuous.Case 3Bilateral retropharyngeal ICA. Minimum distances of the right and left ICAs to the posterior pharyngeal wall were ~ 3.5 mm and ~ 3.3 mm, respectively (high risk of vascular injury). The right has a kinking pathway, the left tortuous.DiscussionCloseness of the vessel to the retropharyngeal wall increases the risk of surgical and non-surgical complications. Noteworthy is that the position of the artery is not constant and can change in position over periods of time.Conclusion Knowledge of the anatomy and variations of the ICA is important for oral and maxillofacial radiologists and surgeons to enable clinicians to take necessary precautions to decrease complications if performing any procedure in the region.
Injuries to the internal carotid artery during simple pharyngeal surgical procedures can be catastrophic for the risk of massive bleeding. The aims of the study were 1) to report five cases of congenital and asymptomatic anomalies of the internal carotid artery with a review of the literature, 2) to assess the relationships between these anomalies and the possible risk in "routine" pharyngeal surgery, and 3) to determine the most accurate imaging techniques to evaluate these anomalies. Retrospective study of five patients with congenital anomalies of the internal carotid artery bulging the pharyngeal wall. METHODS Clinical records, pathology reports, and original imaging features of these kind of vascular lesions (computed tomography scans, three-dimensional time-of-flight magnetic resonance angiogram, and Doppler ultrasonography) were reviewed for each patient; vascular lesions were related to possible risk factors for pharyngeal surgery; and a review of the literature was made. All the patients were admitted for other diseases. The five anomalies, except one, were bulging the posterior pharyngeal wall and were asymptomatic. The peculiar literature referred 14 previous descriptions of similar anomalies. Some of the anomalies of the internal carotid artery can determine a bulge of the posterior pharyngeal wall. Because of the submucous position of the carotid artery at this level, such anomalies can constitute a risk factor for serious hemorrhage in routine surgical procedures that have become outpatient procedures and are often performed by inexperienced surgeons. The three-dimensional time-of-flight magnetic resonance angiogram together with Doppler ultrasonography were shown to be the most accurate imaging techniques to evaluate these anomalies.
Jugular bulb diverticulum is an irregular extension of the jugular bulb into the temporal bone that may be symptomatic or asymptomatic. The jugular bulb has rarely been reported to extend into the occipital condyle; such extension is termed a condylar jugular diverticulum and is characterized as a defect in the occipital condyle contiguous with the jugular bulb. This report details 3 cases of condylar jugular diverticulum. Extension of the jugular bulb into the ipsilateral occipital condyle was noted as an incidental finding on cone-beam computed tomographic (CBCT) images of 3 patients. All 3 patients were asymptomatic, and this finding was unrelated to the initial area of interest. CBCT use is becoming ubiquitous in dentistry, as it allows 3-dimensional evaluation, unlike conventional radiography. Proper interpretation of the entire CBCT is essential, and recognition of the indicators of condylar jugular diverticulum may prevent misdiagnosis of this rare entity.
Noteworthy is th at the position of th e artery is not consta nt and can change in po sition over pe riods of time.