A Rare Case of Isolated, Spontaneous, and Asymptomatic Common Carotid Artery Dissection.

Carotid artery dissection begins as a tear in one of the carotid arteries of the neck, which allows blood under arterial pressure to enter the wall of the artery and split its layers. The result is either an intramural hematoma or an aneurysmal dilatation. It is a significant cause of neurological signs and symptoms in all age groups. The common carotid artery dissection is the least affected and reported in the literature. There are multiple conditions that can cause the common carotid artery dissection including, trauma, procedures, and rarely spontaneous. Herein, we report a very unique and rare case of a female who presented with spontaneous and isolated common carotid artery dissection with no neurological signs and symptoms. Copyright:

INTRODUCTION

Carotid artery dissection occurs when a tear in the inner layer of the wall of the carotid artery causes bleeding into the arterial wall.[1] The dissection most commonly affects the internal carotid artery and rarely affects the common carotid artery.[2] There are many difference mechanisms that can lead to dissection, including extension of aortic dissection, trauma, iatrogenic, and less commonly spontaneous. Patients with dissection can initially present with a range of symptoms from asymptomatic to coma.[2] Herein, we report a very unique case of isolated, spontaneous, and asymptomatic common carotid artery dissection.

CASE REPORT

We report the case of a 51-year-old female with a past medical history of uncontrolled type 2 diabetes mellitus and hypertension, who presented with chest pain radiating to her back and left arm. Her initial vitals were blood pressure 126/85 in the right arm and 127/83 in the left arm, heart rate: 80 BPM, temp: 98.6°F (37.0°C), respiratory rate: 14, SP02: 99% on room air. The patient did not have any neurological symptoms and her physical examination, including a neurological examination, was within the normal limits. Given the description of her pain, a computed tomography (CT) aortogram was done to rule out aortic dissection. The aorta was normal with no signs of dissection; however, there was incidental finding of right common carotid artery dissection. CT angiogram of the neck vessels was done [Figures 1 and 2] as well as a Doppler ultrasound of the carotid arteries. This confirmed the right common carotid artery dissection. The patient underwent a coronary angiogram to investigate her ongoing chest pain, which showed an evidence of three-vessel coronary artery disease with left anterior descending mid segment 80% stenosis, proximal 90% stenosis of first diagonal branch, left circumflex 80% diffuse stenosis, mid RCA had 70% stenotic lesion, and the distal RCA 100% chronic total occlusion lesion. Transthoracic echocardiography was done and was normal with an ejection fraction of 55% and no regional wall motion abnormalities detected. Vascular surgery was consulted for the right coronary artery dissection; however, no surgical intervention was performed due to the lack of neurological symptoms. The patient was offered coronary artery bypass grafting (CABG); however, she wanted time to think, so she was discharged from the hospital in a stable condition on guideline-directed medical therapy with aggressive risk factors modification and a plan to make her decision about CABG upon outpatient follow-up.

Figure 1

Computerized tomographic angiography, axial section shows a dissection in the right common carotid artery dissection

Figure 2

Computerized tomographic angiography, cranial section shows a dissection in the right common carotid artery dissection

DISCUSSION

Dissection of the common carotid artery occurs when the inner intimal layer of the artery tears and allows blood to flow between the layers of the wall forming an intramural hematoma.[1] The pathophysiology is not well understood and likely multifactorial, including genetic predispositions in addition to the environmental factors. The risk factors include hypertension, hyperlipidemia, migraine, hyperhomocysteinemia, in addition to the family history of connective tissue disease.[34567] Marfan syndrome, Ehlers-Danlos syndrome, and fibromuscular dysplasia are connective tissue disorders that can predispose a person to dissection through structural deviations in the main components of connective tissue, collagen, and elastic fibers. This leads to functional impairment of the mechanical stability and elasticity of the arterial wall.[2] There are many mechanisms of dissection. The tear can be spontaneous, an iatrogenic complication of percutaneous carotid artery angiography, an extension from an aortic dissection, associated with mild trauma (sneezing and coughing) or more severe trauma (whiplash injury and aggressive cervical spine rotation manipulation).[89] Carotid artery dissection, mainly the internal carotid, is the most common cause of cerebrovascular accidents in patients younger than 40 and accounts for around 2.5% of stroke in all age groups.[10] There are a wide range of symptoms that can occur in carotid artery dissection from mild headache, facial or neck pain to cranial nerve palsy, retinal ischemia, and acute stroke. Depending on the severity, these symptoms may be transient or can become permanent.[11] Overall, dissection of the common carotid artery is rare. This is likely due to the anatomy of the artery and adjacent structures providing resistance and protection.[12] The spontaneous dissection of the common carotid artery is even less common with less than thirty cases described in the literature, and most of these cases were symptomatic.[13] Herein, we report a unique case of a female who had a common carotid artery dissection, found incidentally, without any neurological signs and symptoms.

It is important to have a high index of suspicion when making the diagnosis of common carotid artery dissection. The wide range of risk factors and symptoms and the rarity of the disease make diagnosing dissection in these patients difficult. In these cases, history and physical examination play a very important role along with different imaging modalities.[14] Both history and physical examination remain to be important elements in carotid artery dissection diagnosis.[14] Different imaging modalities can be used to diagnose this situation. Doppler ultrasound is a noninvasive, cheap, bedside modality that can be used for initial evaluation. However, it has multiple limitations including low sensitivity, it cannot assess the extension of the disease if it involves the intracranial or intrathoracic arteries, and it cannot assess if the patient has a stroke.[15] Computerized tomographic angiography (CTA) has a high sensitivity and specificity for carotid artery dissection diagnosis and can be done at the same time with brain CT to rule out a stroke or intracranial bleeding.[16] The main side effect of CTA is radiation exposure from the scan and the iodine contrast.[17] Finally, magnetic resonance imaging and magnetic resonance angiography are the gold standard in common carotid artery dissection diagnosis.[18] It has the highest sensitivity and specificity, no radiation exposure, and no need for radio-iodine contrast injection.

The main reason for the treatment of common carotid artery dissection is the prevention of transient ischemia attacks occurrence and recurrence. The recurrence rate of ischemic events in carotid artery dissection events occurs between 0% and 13%.[3] There are no data specifically for the dissection of the common carotid artery. Furthermore, there are no clear guidelines for the common carotid artery dissection treatment; thus, we are using the same guidelines for the cervical artery dissection. The American Heart Association/American Stroke Association guidelines recommend antiplatelet therapy or anticoagulation for 3–6 months.[19] It was found that there is no difference in mortality and morbidity between the antiplatelets or the anticoagulation therapy.[20] Another possible treatment option is endovascular angioplasty and stenting which aims to improve perfusion by closing the false lumen and restoring patency of the injured vessel.[19] It is important to note that surgical repair, either open or endovascular, carries lower morbidity and mortality rate in comparison to the internal carotid and vertebral artery because of its anatomical location and easier surgical access.[13]

CONCLUSION

Common carotid artery dissection is a rare entity that may lead to life-threatening complications. Dissection most commonly occurs as a result of trauma of any magnitude or as a direct extension from an aortic artery dissection. Patients rarely present with isolated and spontaneous common carotid artery dissection. We report a very rare case of a patient with isolated and spontaneous common carotid artery dissection who did not have any neurological signs or symptoms. Due to the uncommonness of this condition, there are no clear guidelines for the treatment and management. In our case, we followed the same guidelines for treating the cervical arteries dissection.

Research quality and ethics statement

The authors followed applicable EQUATOR Network (http://www.equator-network.org/) guidelines, notably the CARE guideline, during the conduct of this report.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.