| Carotid artery stenosis |
| Classification and external resources |
The carotid artery is the large vertical artery in red. The blood supply to the carotid artery starts at the arch of the aorta (bottom). The carotid artery divides into the internal carotid artery and the external carotid artery. The internal carotid artery supplies the brain. Plaque often builds up at that division, and causes a narrowing (stenosis). Pieces of plaque can break off and block the small arteries above in the brain, which causes a stroke. Plaque can also build up at the origin of the carotid artery at the aorta. |
| ICD-10 |
I65.2 |
| ICD-9 |
433.1 |
| DiseasesDB |
31178 |
| MedlinePlus |
007427 |
| MeSH |
D016893 |
Carotid stenosis is a narrowing or constriction of the inner surface (lumen) of the carotid artery, usually caused by atherosclerosis .
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Contents
- 1 Signs and symptoms
- 2 Diagnosis
- 3 Screening
- 4 Management
- 5 References
- 6 See also
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Signs and symptoms
The carotid artery is the large artery whose pulse can be felt on both sides of the neck under the jaw. On the right side it starts from the brachiocephalic trunk (a branch of the aorta) as the common carotid artery, and on the left side the common carotid artery comes directly off the aortic arch. At the throat it forks into the internal and external carotid arteries. The internal carotid artery supplies the brain, and the external carotid artery supplies the face. This fork is a common site for atherosclerosis, an inflammatory buildup of atheromatous plaque that can narrow the lumen of the common or internal carotid arteries.
The plaque can be stable and asymptomatic, or it can be a source of embolization. Emboli break off from the plaque and travel through the circulation to blood vessels in the brain. As the vessel gets smaller, they can lodge in the vessel wall and restrict blood flow to parts of the brain which that vessel supplies. This ischemia can either be temporary, yielding a transient ischemic attack, or permanent resulting in a thromboembolic stroke.
Clinically, risk of stroke from carotid stenosis is evaluated by the presence or absence of symptoms and the degree of stenosis on imaging.
Transient ischemic attacks (TIA's) are a warning sign, and are often followed by severe permanent strokes, particularly within the first two days. TIA's by definition last less than 24 hours, and frequently take the form of a weakness or loss of sensation of a limb or the trunk on one side of the body, or the loss of sight (amaurosis fugax) in one eye. Less common symptoms are artery sounds (bruits), or ringing in the ears (tinnitus).
Diagnosis
Section of carotid artery with plaque. Blood flows from the common carotid artery (bottom), and divides into the internal carotid artery (left) and external carotid artery (right). The atherosclerotic plaque is the dark mass on the left.
Carotid stenosis is usually diagnosed by color flow duplex ultrasound scan of the carotid arteries in the neck. This involves no radiation, no needles and no contrast agents that may cause allergic reactions. This test has moderate sensitivity and specificity, and yields many false-positive results.
Typically duplex ultrasound scan is the only investigation required for decision making in carotid stenosis. Occasionally further imaging is required. One of several different imaging modalities, such as angiogram, computed tomography angiogram (CTA) or magnetic resonance imaging angiogram (MRA) may be useful. Each imaging modality has its advantages and disadvantages - the investigation chosen will depend on the clinical question and the imaging expertise, experience and equipment available.
Screening
The U.S. Preventive Services Task Force (USPSTF) recommends against screening for asymptomatic carotid artery stenosis in the general adult population.[1]
Management
Options include:
- Medications alone (an antiplatelet drug (or drugs) and control of risk factors for atherosclerosis)
- Medical management plus carotid endarterectomy or carotid stenting
The goal of treatment is to reduce the risk of stroke (cerebrovascular accident). Intervention (carotid endarterectomy or carotid stenting) can cause stroke, however where the risk of stroke from medical management alone is high, intervention may be beneficial. In selected, high-risk trial participants with asymptomatic severe carotid artery stenosis, carotid endarterectomy by selected surgeons reduces the 5-year absolute incidence of all strokes or perioperative death by approximately 5%. In excellent centers, carotid endarterectomy is associated with a 30-day stroke or mortality rate of about 3%; some areas have higher rates.[1]
Clinical guidelines (such as those of National Institute for Clinical Excellence (NICE)[citation needed]) recommend that all patients with carotid stenosis be given medication, usually anti-hypertensive drugs, anti-clotting drugs, anti-platelet drugs (such as aspirin), and especially statins (which were originally prescribed for their cholesterol-lowering effects but were also found to reduce inflammation and stabilize plaque).
NICE and other guidelines also recommend that patients with symptomatic carotid stenosis be given carotid endarterectomy urgently, since the greatest risk of stroke is within days. Carotid endarterectomy reduces the risk of stroke or death from carotid emboli by about half.
For people with stenosis but no symptoms, the surgical recommendations are less clear and controversial. Such patients have a historical risk of stroke of about 1-2% per year. Carotid endarterectomy has a surgical risk of stroke or death of about 2-4% in the best institutions. Carotid endarterectomy reduced major stroke and death by about half, even after surgical death and stroke was taken into account.[2] According to the Cochrane Collaboration the absolute benefit of surgery is small.[citation needed]
Surgery
Benefits of endarterectomy are greater than those of stenting.[3] A 2010 study found benefits (reduced strokes) from carotid endarterectomy in those without symptoms who are under 75.[4]
References
- ^ a b Screening for Carotid Artery Stenosis. December 2007. U.S. Preventive Services Task Force. Agency for Healthcare Research and Quality, Rockville, MD.
- ^ Naylor AR (July 2004). "The Asymptomatic Carotid Surgery Trial: bigger study, better evidence". Br J Surg 91 (7): 787–9. doi:10.1002/bjs.4552. PMID 15227684.
- ^ Brott TG, Hobson RW, Howard G, et al. (July 2010). "Stenting versus endarterectomy for treatment of carotid-artery stenosis". N. Engl. J. Med. 363 (1): 11–23. doi:10.1056/NEJMoa0912321. PMC 2932446. PMID 20505173. http://content.nejm.org/cgi/content/full/NEJMoa0912321.
- ^ Halliday A, Harrison M, Hayter E, et al. (September 2010). "10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial". Lancet 376 (9746): 1074–84. doi:10.1016/S0140-6736(10)61197-X. PMID 20870099.
See also
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CNS disease, Vascular disease: Cerebrovascular diseases (G45–G46 and I60–I69, 430–438)
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Brain ischemia/
cerebral infarction
(ischemic stroke/TIA) |
| TACI, PACI |
- precerebral: Carotid artery stenosis
- cerebral: MCA
- ACA
- Amaurosis fugax
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| POCI |
- precerebral: Anterior spinal artery syndrome
- Vertebrobasilar insufficiency
- Subclavian steal syndrome
- brainstem: medulla
- Medial medullary syndrome
- Lateral medullary syndrome
- pons
- Medial pontine syndrome/Foville's
- Lateral pontine syndrome/Millard-Gubler
- midbrain
- Weber's
- Benedikt
- Claude's
- cerebral: PCA
- Lacunar stroke
- Dejerine–Roussy syndrome
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| General |
- cerebral: Cerebral venous sinus thrombosis
- CADASIL
- Binswanger's disease
- Transient global amnesia
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Intracranial hemorrhage
(hemorrhagic stroke) |
| Extra-axial |
- Epidural
- Subdural
- Subarachnoid
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| Cerebral/Intra-axial |
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| Brainstem |
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| Aneurysm |
- Cerebral aneurysm
- Intracranial berry aneurysm
- Charcot-Bouchard aneurysm
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| Other/general |
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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anat (a:h/u/t/a/l,v:h/u/t/a/l)/phys/devp/cell/prot
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noco/syva/cong/lyvd/tumr, sysi/epon, injr
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proc, drug (C2s+n/3/4/5/7/8/9)
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Cardiovascular disease: vascular disease · Circulatory system pathology (I70–I99, 440–456)
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Arteries, arterioles
and capillaries |
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Inflammation
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Arteritis (Aortitis) · Buerger's disease
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Arterial occlusive disease/
peripheral vascular disease
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Arteriosclerosis
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Atherosclerosis (Foam cell, Fatty streak, Atheroma, Intermittent claudication) · Monckeberg's arteriosclerosis · Arteriolosclerosis (Hyaline, Hyperplastic, oxycholesterol, cholesterol, LDL, trans fat)
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Stenosis
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Renal artery stenosis · Carotid artery stenosis
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Other
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Fibromuscular dysplasia · Degos disease · Aortoiliac occlusive disease · Raynaud's phenomenon/Raynaud's disease · Erythromelalgia
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Aneurysm/dissection/
pseudoaneurysm
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torso: Aortic aneurysm (Thoracic aortic aneurysm, Abdominal aortic aneurysm) · Aortic dissection · Coronary artery aneurysm
head/neck: Cerebral aneurysm · Intracranial berry aneurysm · Carotid artery dissection · Vertebral artery dissection · Familial aortic dissection
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Vascular malformation
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Arteriovenous malformation · Arteriovenous fistula · Telangiectasia (Hereditary hemorrhagic telangiectasia)
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Vascular nevus
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Spider angioma · Halo nevus · Cherry hemangioma
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| Veins |
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Inflammation
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Phlebitis
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Venous thrombosis/
Thrombophlebitis
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primarily lower limb (Deep vein thrombosis)
abdomen (Hepatic veno-occlusive disease, Budd–Chiari syndrome, May-Thurner syndrome, Portal vein thrombosis, Renal vein thrombosis)
upper limb/torso (Paget-Schroetter disease, Mondor's disease)
head (Cerebral venous sinus thrombosis)
Post-thrombotic syndrome
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Varicose veins
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Varicocele · Gastric varices · Portacaval anastomosis (Hemorrhoid, Esophageal varices, Caput medusae)
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Other
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Superior vena cava syndrome · Inferior vena cava syndrome · Venous ulcer · Chronic venous insufficiency · Chronic cerebrospinal venous insufficiency
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| Arteries or veins |
Vasculitis · Thrombosis · Embolism (Pulmonary embolism, Cholesterol embolism, Paradoxical embolism) · Angiopathy (Macroangiopathy, Microangiopathy)
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| Blood pressure |
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Hypertension
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Hypertensive heart disease · Hypertensive nephropathy · Essential hypertension · Secondary hypertension (Renovascular hypertension) · Pulmonary hypertension · Malignant hypertension · Benign hypertension · Systolic hypertension · White coat hypertension
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Hypotension
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Orthostatic hypotension
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anat (a:h/u/t/a/l,v:h/u/t/a/l)/phys/devp/cell/prot
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noco/syva/cong/lyvd/tumr, sysi/epon, injr
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proc, drug (C2s+n/3/4/5/7/8/9)
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