Carotid Artery Stenosis (Clinical)

Overview

Definition

Carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) is a narrowing of the common and internal carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy (ICAs) secondary to atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis.

Epidemiology^[1–3,5]

• Affects more men than women until the age of 75
• Moderate and severe carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) risk increases with age:
  • 0.5% prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in the 6th decade
  • 10% prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship > 80 years of age
• Major cause of disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment and fatal stroke (with atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis of the ICA ICA Diabetes Mellitus accounting for up to 12% of ischemic strokes).

Etiology^[5]

• Atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis
• Modifiable risk factors:
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
  • Hypercholesterolemia Hypercholesterolemia A condition with abnormally high levels of cholesterol in the blood. It is defined as a cholesterol value exceeding the 95th percentile for the population. Lipid Disorders
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases
  • Alcohol use
  • Sedentary lifestyle
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
  • Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity
• Non-modifiable risk factors:
  • Increasing age
  • Family history Family History Adult Health Maintenance

Pathophysiology

Carotid stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) can cause symptoms from a state of low flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure or embolization Embolization A method of hemostasis utilizing various agents such as gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and intracranial arteriovenous malformations, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage. Gastrointestinal Bleeding.

Low flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure results from progressive narrowing of the carotid artery:

• Development of atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis (local thickening of the arterial wall due to plaque Plaque Primary Skin Lesions deposition)
• Atherosclerotic plaques consist of a lipid core covered with a fibrous Fibrous Fibrocystic Change cap.
• Atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis commonly develops at the site of endothelial injury secondary to increased blood turbulence.
• Plaques, therefore, typically develop at the bifurcation of the common carotid artery Common carotid artery The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external and internal carotid arteries. Carotid Arterial System: Anatomy.
• Narrowing of the lumen can produce symptoms, especially if there is inadequate collateral circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification.

Embolization Embolization A method of hemostasis utilizing various agents such as gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and intracranial arteriovenous malformations, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage. Gastrointestinal Bleeding:

• Calcified plaques are less likely to be inflamed and are less prone to rupture.
• Plaques are more susceptible to rupture when the fibrous Fibrous Fibrocystic Change cap becomes thin with the remodeling of the extracellular matrix Extracellular matrix A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere. Hypertrophic and Keloid Scars by matrix metalloproteinases Matrix metalloproteinases A family of zinc-dependent metalloendopeptidases that is involved in the degradation of extracellular matrix components. Hypertrophic and Keloid Scars.
• Rupture of the plaque Plaque Primary Skin Lesions can lead to thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus and embolization Embolization A method of hemostasis utilizing various agents such as gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and intracranial arteriovenous malformations, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage. Gastrointestinal Bleeding, resulting in a stroke.
• Important features of rupture-prone carotid plaques:
  • Increased numbers of inflammatory cells (e.g., macrophages Macrophages The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood monocytes. Main types are peritoneal macrophages; alveolar macrophages; histiocytes; kupffer cells of the liver; and osteoclasts. They may further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or langhans giant cells. Innate Immunity: Phagocytes and Antigen Presentation)
  • Fissures/ ulceration Ulceration Corneal Abrasions, Erosion, and Ulcers
  • Large lipid core
  • Thin fibrous Fibrous Fibrocystic Change cap
  • Endothelial denudation
  • Platelet aggregation Platelet aggregation The attachment of platelets to one another. This clumping together can be induced by a number of agents (e.g., thrombin; collagen) and is part of the mechanism leading to the formation of a thrombus. Hemostasis

Clinical Presentation

Asymptomatic carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS): carotid atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis without a history of ipsilateral carotid territory ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke or transient ischemic attack Transient ischemic attack Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) ( TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA)) in the past 6 months^[1,2]

Symptomatic carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS):^[1,3]

• Carotid symptoms (TIAs or ischemic strokes) within the past 6 months
• TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA): results from transient cerebral ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage without acute infarction, producing transient neurologic symptoms
  • Embolic: usually lasts a few hours
  • Low flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure: usually lasts a few minutes
• Ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke:
  • Brain ischemia Brain Ischemia Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia. Prolonged ischemia is associated with brain infarction. Ischemic Stroke to thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus, embolism, or hypoperfusion
  • Can result in acute brain-tissue infarction
  • Persistent neurologic symptoms may result in permanent damage.
• Neurologic symptoms:
  • Sudden, and attributable to the ICA ICA Diabetes Mellitus distribution (ipsilateral to the significant carotid atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis).
  • Symptoms include:
    • Amaurosis fugax Amaurosis fugax Transient complete or partial monocular blindness due to retinal ischemia. This may be caused by emboli from the carotid artery (usually in association with carotid stenosis) and other locations that enter the central retinal artery. Carotid Artery Stenosis (painless monocular vision Vision Ophthalmic Exam loss)
    • Hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy/ arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy weakness, numbness, or heaviness
    • Contralateral hemiplegia
    • Ipsilateral facial weakness
    • Aphasia Aphasia A cognitive disorder marked by an impaired ability to comprehend or express language in its written or spoken form. This condition is caused by diseases which affect the language areas of the dominant hemisphere. Clinical features are used to classify the various subtypes of this condition. General categories include receptive, expressive, and mixed forms of aphasia. Ischemic Stroke (dominant hemisphere)
    • Anosognosia Anosognosia Alzheimer Disease ( neglect Neglect Child Abuse; nondominant hemisphere)

Diagnosis

Carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) is usually suspected based on a presentation consistent with a TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) or a stroke.^[10]

History^[10]

• Previous documented strokes or TIAs
• Transient weakness, numbness, speech impairment, or vision Vision Ophthalmic Exam loss
• History of atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis, hypercholesterolemia Hypercholesterolemia A condition with abnormally high levels of cholesterol in the blood. It is defined as a cholesterol value exceeding the 95th percentile for the population. Lipid Disorders/ hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension

Physical exam^[10]

• Focal neurological deficits Focal Neurological Deficits Brain Abscess (would indicate a stroke)
• Carotid bruit Carotid bruit Carotid Artery Stenosis: heard with a stethoscope over the bifurcation/proximal internal carotid artery Internal carotid artery Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose. Carotid Arterial System: Anatomy
• Diminished carotid pulse Carotid Pulse Cardiovascular Examination (severe stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)/occlusion)

Imaging^[7,10.12]

• Carotid duplex ultrasound Carotid duplex ultrasound Carotid Artery Stenosis (CDUS):
  • Detects focal increase in blood-flow velocity, which is indicative of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Accurate in determining the degree of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Does not provide information on plaque Plaque Primary Skin Lesions morphology
  • Noninvasive 
• CT angiogram CT angiogram A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests ( CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests):
  • Provides anatomical image of vessels and surrounding structures
    • Important structures visualized: aortic arch Aortic arch Mediastinum and Great Vessels: Anatomy, supra-aortic trunks, carotid bifurcation, distal ICA ICA Diabetes Mellitus, and intracranial circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment
    • This advantage is especially important when carotid artery stenting is being considered.^[12]
  • Useful in detecting high-grade stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) and occlusion
  • Requires contrast agent (may limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation use in those with impaired renal function)
• MRA MRA Imaging of the Heart and Great Vessels:
  • Accurately detects the degree of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Provides an image of anatomy and plaque Plaque Primary Skin Lesions morphology
  • Similar to CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests, has the advantage of imaging the surrounding vessels and structures^[12]
  • Atherosclerotic tissue analysis can be performed (e.g., detects intra-plaque hemorrhages).
  • Expensive and time-consuming
  • Not always available in all facilities
• Cerebral angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery:
  • Considered the gold standard (but rarely required)
  • Provides information on the entire carotid artery system, including contralateral side and collateral circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment
  • Invasive, expensive, and carries the risk of complications (e.g., stroke)

Measuring stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)^[1,11,12]

• Severity of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) (3 categories based on the luminal diameter reduction):
  • Mild: < 50% stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Moderate: 50%–69% stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Severe:
    • 70%–99% stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
    • A strong predictor for stroke
• There are different methods for measuring stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS).
  • European Carotid Surgery Trial (ECST):
    • Numerator: minimum residual luminal diameter 
    • Denominator: the estimated vessel diameter where the stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) was measured (usually the carotid bulb)
  • North American Symptomatic Carotid Endarterectomy Endarterectomy Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called atherectomy. Intestinal Ischemia Trial (NASCET):
    • Numerator: minimum residual luminal diameter 
    • Denominator: diameter of a disease-free ICA ICA Diabetes Mellitus segment distal to the stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
• Generally, NASCET criteria are used by the Stroke ( American Heart Association American Heart Association A voluntary organization concerned with the prevention and treatment of heart and vascular diseases. Heart Failure) guidelines, National Health Service (UK), and European Society of Vascular Surgery Vascular surgery Vascular surgery is the specialized field of medicine that focuses on the surgical management of the pathologies of the peripheral circulation. The main goal of most vascular procedures is to restore circulatory function to the affected vessels by relieving occlusions or by redirecting blood flow (e.g., bypass). Vascular Surgery.^[1,10,14]
  • 50% NASCET stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) equates to 75% ECST stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS).
  • 70% NASCET stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) is about 85% of ECST stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS).
• Importance of the degree of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS): essential in determining which patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship would benefit from revascularization Revascularization Thromboangiitis Obliterans (Buerger’s Disease)

Diagnostic approach^[12,19]

• Emergency setting:
  • When presenting with an acute ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke or TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA), emergency brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification imaging ( brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification MRI or CT) is obtained on arrival.
  • Noncontrast brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification CT also excludes intracerebral hemorrhage Intracerebral Hemorrhage Intracerebral hemorrhage (ICH) refers to a spontaneous or traumatic bleed into the brain parenchyma and is the 2nd-most common cause of cerebrovascular accidents (CVAs), commonly known as stroke, after ischemic CVAs. Intracerebral Hemorrhage as a cause of symptoms.
  • However, brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification MRI diffusion-weighted imaging Diffusion-Weighted Imaging Imaging of the Head and Brain ( DWI DWI Imaging of the Head and Brain) is preferred for TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA), given its greater sensitivity in detecting small infarcts.^[20]
• Testing for suspected carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS):
  • CDUS (1st-line)
  • When carotid artery stenting or endarterectomy Endarterectomy Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called atherectomy. Intestinal Ischemia is considered, CDUS is followed by MRA MRA Imaging of the Heart and Great Vessels or CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests to evaluate the severity of stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) and the surrounding structures.
  • If there are discrepancies in imaging, conventional angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery is considered.
  • In a patient with a recent TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) or stroke, and in whom stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) is > 50%, it is reasonable to obtain a workup for cardioembolism with:
    • Echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA)
    • 24–72 hours of rhythm monitoring
• Surveillance Surveillance Developmental Milestones and Normal Growth:
  • Those found to have carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) < 50%: generally followed with CDUS annually^[14]
  • Those with carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) ≥ 50%: see Management section
• Screening Screening Preoperative Care:
  • US Preventive Services Task Force (USPSTF) recommends against screening Screening Preoperative Care for asymptomatic carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) in the general population.^[9]
    • Auscultation of carotid bruits is inaccurate in detecting carotid stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS).
    • Without a history of TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA), stroke, or other neurologic features referable to the carotid arteries Carotid Arteries Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery. Carotid Arterial System: Anatomy, no screening Screening Preoperative Care is recommended.
  • The Society of Vascular Surgery Vascular surgery Vascular surgery is the specialized field of medicine that focuses on the surgical management of the pathologies of the peripheral circulation. The main goal of most vascular procedures is to restore circulatory function to the affected vessels by relieving occlusions or by redirecting blood flow (e.g., bypass). Vascular Surgery (SVS) in the US agrees with above, but adds that:^[9,13]
    • Selected asymptomatic patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship at high risk for carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) can undergo screening Screening Preoperative Care, especially if the patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are open to carotid intervention if significant stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) is found.
    • CDUS is the preferred imaging method.

Management

Management may vary based on practice location. The following information is based on US and European guidelines.

Regardless of symptoms, intensive medical management is recommended in all patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with atherosclerotic carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS); this involves lifestyle intervention and pharmacologic therapy.

Lifestyle modifications

• Stop smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases:^[6,7]
  • Counseling with or without drug therapy to aid quitting
  • Avoidance of environmental tobacco exposure
• Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery:^[16,17]
  • 5%–10% reduction in weight improves vascular risk factors (e.g., ↓ blood pressure, cholesterol Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Cholesterol Metabolism, glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance levels).
  • Treatment options:
    • Counseling to change eating patterns
    • Medications to suppress appetite
    • Bariatric surgery Bariatric surgery Bariatric surgery refers to a group of invasive procedures used to surgically reduce the size of the stomach to produce early satiety, decrease food intake (restrictive type) and/or alter digestion, and artificially induce malabsorption of nutrients (malabsorptive type). The ultimate goal of bariatric surgery is drastic weight loss. Bariatric Surgery
• Nutrition:^[6,16,17]
  • DASH ( Dietary Approaches to Stop Hypertension Dietary Approaches To Stop Hypertension Dietary recommendations that promote reduction in or prevention of high blood pressure. Recommendations include increasing intake of fruits and vegetables, and high-fiber, low-fat foods and reducing the intake of dietary sodium and high fat foods. Hypertension) diet (rich in fruits and vegetables, and low in dairy and saturated/total fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis)
    • Recommended for people with hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
    • Reduction of Na⁺ by 1 g/day, or a total < 2.5 g/day 
  • Mediterranean diet (a diet rich in monounsaturated fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis and plant-based foods and high fish FISH A type of in situ hybridization in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei. Chromosome Testing consumption, with high consumption of either extra virgin olive oil or nuts)
• Limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation alcohol intake:^[6,7,18]
  • Men: < 2 drinks a day
  • Women: < 1 drink a day
  • For individuals with substance use disorders, specialized services are recommended to manage dependency.
• Regular Regular Insulin exercise:^[6,7,17]
  • 10 minutes of moderate-intensity exercise 4 days a week, or 20 minutes of vigorous exercise 2 days a week
  • For individuals willing to increase activity, group exercise classes with counseling on healthy lifestyle habits are recommended.
  • For individuals who sit for long uninterrupted periods during the day, 3 minutes of standing or light exercise every 30 minutes is recommended.

Medications

Antiplatelet therapy (e.g., aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs), clopidogrel Clopidogrel A ticlopidine analog and platelet purinergic p2y receptor antagonist that inhibits adenosine diphosphate-mediated platelet aggregation. It is used to prevent thromboembolism in patients with arterial occlusive diseases; myocardial infarction; stroke; or atrial fibrillation. Antiplatelet Drugs):^[6,7]

• Used in different settings: acute stroke/ TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) and secondary prevention
• Favored over anticoagulation Anticoagulation Pulmonary Hypertension Drugs therapy unless there are indications for anticoagulation Anticoagulation Pulmonary Hypertension Drugs, such as:
  • Atrial fibrillation Atrial fibrillation Atrial fibrillation (AF or Afib) is a supraventricular tachyarrhythmia and the most common kind of arrhythmia. It is caused by rapid, uncontrolled atrial contractions and uncoordinated ventricular responses. Atrial Fibrillation
  • Mechanical heart valve
  • Venous thromboembolism Thromboembolism Obstruction of a blood vessel (embolism) by a blood clot (thrombus) in the blood stream. Systemic Lupus Erythematosus
  • Intraventricular thrombus Intraventricular thrombus Takotsubo Cardiomyopathy

Antithrombotic therapy (immediate) in TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) or acute ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke:^[19]

• Note that in all patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship presenting with acute ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke:
  • Evaluate for reperfusion therapy (thrombolysis and/or thrombectomy Thrombectomy Surgical removal of an obstructing clot or foreign material from a blood vessel at the point of its formation. Removal of a clot arising from a distant site is called embolectomy. Vascular Surgery).
  • If IV thrombolysis is performed, antithrombotic agents are not given in the 1st 24 hours.
  • If there are no other contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation, antithrombotic treatment is initiated.
• For recent (< 24 hours) minor stroke (NIHSS score ≤ 5) or high-risk TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) (ABCD² score ≥ 4):
  • Initiate dual antiplatelet therapy (DAPT) on the 1st day, if possible.
  • Dosing: aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) ( loading dose Loading Dose Dosage Calculation, 160–325 mg, then 50–100 mg/day) and clopidogrel Clopidogrel A ticlopidine analog and platelet purinergic p2y receptor antagonist that inhibits adenosine diphosphate-mediated platelet aggregation. It is used to prevent thromboembolism in patients with arterial occlusive diseases; myocardial infarction; stroke; or atrial fibrillation. Antiplatelet Drugs ( loading dose Loading Dose Dosage Calculation, 300–600 mg)
  • In cases due to ICA ICA Diabetes Mellitus and common carotid artery Common carotid artery The two principal arteries supplying the structures of the head and neck. They ascend in the neck, one on each side, and at the level of the upper border of the thyroid cartilage, each divides into two branches, the external and internal carotid arteries. Carotid Arterial System: Anatomy stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS), DAPT is given for 21 days (up to 30 days)^[10] then switched to monotherapy.
• For recent (< 24 hours) moderate-severe stroke (NIHSS score > 5) or low-risk TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) (ABCD² score < 4): administer aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) 162‒325 mg/daily
• Ticagrelor Ticagrelor An adenosine triphosphate analogue and reversible p2y12 purinoceptor antagonist that inhibits adp-mediated platelet aggregation. It is used for the prevention of thromboembolism by patients with acute coronary syndrome or a history of myocardial infarction. Antiplatelet Drugs + aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) treatment has been used in mild-to-moderate acute ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke (NIHSS score ≤5) or TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA):^[8]
  • Showed lower risk of stroke or death in 30 days as compared with aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) alone
  • No difference in long-term disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment, however, with no difference in 90-day outcomes
  • Ticagrelor Ticagrelor An adenosine triphosphate analogue and reversible p2y12 purinoceptor antagonist that inhibits adp-mediated platelet aggregation. It is used for the prevention of thromboembolism by patients with acute coronary syndrome or a history of myocardial infarction. Antiplatelet Drugs may be a reasonable option for those with contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation to aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) treatment.

Antithrombotic therapy options for secondary prevention:^{[5,6,7,10,12]}

• Aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) 50–325 mg by mouth, once a day
• Clopidogrel Clopidogrel A ticlopidine analog and platelet purinergic p2y receptor antagonist that inhibits adenosine diphosphate-mediated platelet aggregation. It is used to prevent thromboembolism in patients with arterial occlusive diseases; myocardial infarction; stroke; or atrial fibrillation. Antiplatelet Drugs 75 mg by mouth, once a day
• Aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) 25 mg and extended-release dipyridamole Dipyridamole A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. Phosphodiesterase Inhibitors 200 mg by mouth, twice daily

High-intensity statin treatment (promotes plaque Plaque Primary Skin Lesions stability):^[6,7,12]

• Ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke or TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) with no known cardiac risk factors or evidence of cardiac emboli:
  • Goal: LDL cholesterol Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Cholesterol Metabolism (LDL-C) < 100 mg/dL
  • Atorvastatin Atorvastatin A pyrrole and heptanoic acid derivative, hydroxymethylglutaryl-CoA reductase inhibitor (statin), and anticholesteremic agent that is used to reduce serum levels of ldl-cholesterol; apolipoprotein b; and triglycerides. It is used to increase serum levels of hdl-cholesterol in the treatment of hyperlipidemias, and for the prevention of cardiovascular diseases in patients with multiple risk factors. Statins 80 mg daily is recommended. 
• Ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke or TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) with known atherosclerotic disease:
  • Goal: LDL-C < 70 mg/dL (US)
  • Goal: LDL-C 55 mg/dL and reduction of initial LDL-C by > 50% (European Society of Cardiology)
  • Atorvastatin Atorvastatin A pyrrole and heptanoic acid derivative, hydroxymethylglutaryl-CoA reductase inhibitor (statin), and anticholesteremic agent that is used to reduce serum levels of ldl-cholesterol; apolipoprotein b; and triglycerides. It is used to increase serum levels of hdl-cholesterol in the treatment of hyperlipidemias, and for the prevention of cardiovascular diseases in patients with multiple risk factors. Statins 80 mg daily is recommended.
  • Add ezetimibe Ezetimibe An azetidine derivative and anticholesteremic agent that inhibits intestinal sterol absorption. It is used to reduce total cholesterol; ldl cholesterol, and apolipoproteins B in the treatment of hyperlipidemias. Lipid Control Drugs 10 mg daily if goal not achieved
  • If further control is needed despite statin + ezetimibe Ezetimibe An azetidine derivative and anticholesteremic agent that inhibits intestinal sterol absorption. It is used to reduce total cholesterol; ldl cholesterol, and apolipoproteins B in the treatment of hyperlipidemias. Lipid Control Drugs, consider a PCSK9 inhibitor ( alirocumab Alirocumab Lipid Control Drugs, evolocumab Evolocumab Lipid Control Drugs).

Antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs:^[6,7]

• Goal BP < 130/80 mm Hg: for individuals with or without previous diagnosis of TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) or stroke
• Tailor antihypertensive regimen to patient’s comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus, pharmacologic class, and patient’s preference for increased compliance Compliance Distensibility measure of a chamber such as the lungs (lung compliance) or bladder. Compliance is expressed as a change in volume per unit change in pressure. Veins: Histology. (See Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension page for drug dosages.)
• Consider thiazide Thiazide Heterocyclic compounds with sulfur and nitrogen in the ring. This term commonly refers to the benzothiadiazines that inhibit sodium-potassium-chloride symporters and are used as diuretics. Hyponatremia diuretics Diuretics Agents that promote the excretion of urine through their effects on kidney function. Heart Failure and Angina Medication, angiotensin-converting–enzyme inhibitors, and angiotensin II Angiotensin II An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the c-terminal by angiotensin converting enzyme. The amino acid in position 5 varies in different species. To block vasoconstriction and hypertension effect of angiotensin II, patients are often treated with ace inhibitors or with angiotensin II type 1 receptor blockers. Renal Sodium and Water Regulation receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors blockers, as 1st-line drugs, to reduce risk of stroke.

Surgical revascularization Revascularization Thromboangiitis Obliterans (Buerger’s Disease)^[6,10,14,20]

Individuals with newly diagnosed carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) with or without symptoms should be evaluated by a vascular surgeon for carotid revascularization Revascularization Thromboangiitis Obliterans (Buerger’s Disease).

Carotid endarterectomy Endarterectomy Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called atherectomy. Intestinal Ischemia ( CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers):

• Involves surgical removal of the atherosclerotic plaque Plaque Primary Skin Lesions from the carotid artery
• Indications are based on risk-benefit analysis:
  • Stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) 80%–99% in asymptomatic patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
  • Stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) > 50% in symptomatic patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship (men) or > 70% (women)
• Annual surveillance Surveillance Developmental Milestones and Normal Growth for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship not undergoing surgery (usually with duplex)
• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship can become candidates for surgery over time with disease progression.
• Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation to CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers:
  • Symptomatic carotid artery stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) < 50%
  • Ipsilateral carotid occlusion (100% stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS))
  • Prior ipsilateral endarterectomy Endarterectomy Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called atherectomy. Intestinal Ischemia
  • History of neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess surgery or irradiation
  • Life expectancy Life expectancy Based on known statistical data, the number of years which any person of a given age may reasonably expected to live. Population Pyramids < 5 years
• CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers is generally recommended unless the perioperative morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status is > 6% or CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers is contraindicated (American College of Surgeons National Surgical Quality Improvement Program, risk calculator).

Carotid angioplasty Carotid angioplasty Carotid Artery Stenosis and stenting:

• Less invasive alternative to CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers
• Greater risk of periprocedural stroke than CEA CEA A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment. Serum Tumor Markers
• Recommended for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with:
  • A carotid lesion that is not accessible with surgery
  • Radiation-induced stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS)
  • Restenosis after endarterectomy Endarterectomy Surgical excision, performed under general anesthesia, of the atheromatous tunica intima of an artery. When reconstruction of an artery is performed as an endovascular procedure through a catheter, it is called atherectomy. Intestinal Ischemia
  • Cardiac, pulmonary, or other diseases, which greatly increase the risk of anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts and surgery
  • Unfavorable neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess anatomy including contralateral vocal-cord paralysis, open tracheostomy Tracheostomy Surgical formation of an opening into the trachea through the neck, or the opening so created. Laryngomalacia and Tracheomalacia, or prior radical surgery

Differential Diagnosis

• Vertebrobasilar insufficiency: stenosis Stenosis Hypoplastic Left Heart Syndrome (HLHS) of vertebral and basilar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology secondary to atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis, which results in compromised circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment to the posterior brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. Symptoms include dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)/ vertigo Vertigo Vertigo is defined as the perceived sensation of rotational motion while remaining still. A very common complaint in primary care and the ER, vertigo is more frequently experienced by women and its prevalence increases with age. Vertigo is classified into peripheral or central based on its etiology. Vertigo, numbness, slurred speech Slurred Speech Cerebellar Disorders, weakness, confusion, and loss of coordination Coordination Cerebellar Disorders. Diagnosis is based on MRA MRA Imaging of the Heart and Great Vessels or CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests, and treatment is focused on the control of hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension and cholesterol Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Cholesterol Metabolism, and lifestyle modifications.
• Embolic strokes from other sources: Carotid atherosclerotic plaques are a very common source of emboli to cerebral vessels, but other sources include the heart and aortic arch Aortic arch Mediastinum and Great Vessels: Anatomy. Presenting symptoms are very similar to TIA TIA Transient ischemic attack (TIA) is a temporary episode of neurologic dysfunction caused by ischemia without infarction that resolves completely when blood supply is restored. Transient ischemic attack is a neurologic emergency that warrants urgent medical attention. Transient Ischemic Attack (TIA) and strokes originating from the carotids. Diagnosis is established based on imaging studies, and treatment includes management of acute stroke and the underlying disease.
• Carotid artery dissection Carotid artery dissection The splitting of the vessel wall in one or both (left and right) internal carotid arteries. Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the internal carotid artery and aneurysm formation. Dissection of the Carotid and Vertebral Arteries: a tear in the intimal layer of the carotid wall that results in separation of the wall layers with blood getting in between the layers, resulting in occlusion of the vessel lumen.  Carotid artery dissection Carotid artery dissection The splitting of the vessel wall in one or both (left and right) internal carotid arteries. Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the internal carotid artery and aneurysm formation. Dissection of the Carotid and Vertebral Arteries is the most common cause of stroke in young adults and may occur spontaneously or secondary to neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess trauma. Diagnosis is established with imaging. Treatment is with anticoagulants Anticoagulants Anticoagulants are drugs that retard or interrupt the coagulation cascade. The primary classes of available anticoagulants include heparins, vitamin K-dependent antagonists (e.g., warfarin), direct thrombin inhibitors, and factor Xa inhibitors. Anticoagulants and surgical interventions in some cases.