| Carotid stenting | |
|---|---|
 Illustration showing the process of carotid artery stenting | |
| ICD-9-CM | 00.55, 00.63, 39.90, |
Carotid artery stenting is an endovascular procedure where a stent is deployed within the lumen of the carotid artery to treat narrowing of the carotid artery and decrease the risk of stroke. It is used to treat narrowing of the carotid artery in high-risk patients, when carotid endarterectomy is considered too risky.
Carotid stenting is used to reduce the risk of stroke associated with carotid artery stenosis. Carotid stenosis can have no symptoms, or have symptoms such as transient ischemic attacks (TIAs) or strokes.
While historically endarterectomy has been the treatment for carotid stenosis, stenting is an alternative intervention for patients who are not candidates for surgery. High risk factors for endarterectomy, which would favor stenting instead, include medical comorbidities (severe heart disease, heart failure, severe lung disease) and anatomic features (contralateral carotid occlusion, radiation therapy to the neck, prior ipsilateral carotid artery surgery, intra-thoracic or intracranial carotid disease) that would make surgery difficult and risky. [1]
While rates of stroke and death after both surgery and stenting are low, rates of stroke and death after stenting may be higher than endartererectomy, particularly for transfemoral stenting in patients over age 70. [2]
Carotid stenting involves the placement of a stent across the stenosis in the carotid artery. It can be performed under general or local anesthesia.
The stent may be placed from the femoral artery, radial artery, or from the common carotid artery at the base of the neck. Critical steps in both approaches are vascular access, crossing the stenosis with a wire, deploying a stent across the lesion, and removing the vascular access. A number of other steps may or may not be performed, including the use of a cerebral protection device, pre- or post-stent balloon angioplasty and cerebral angiography.
The trans-femoral route is the traditional approach to carotid stenting. The vast majority of these procedures are performed under local anesthesia. In this technique, puncture of the common femoral artery is used to gain access to the arterial system. Wire and sheath are advanced through the aorta to the common carotid artery on the side to be treated. Flow reversal or filter cerebral protection may be used. The procedure is typically performed percutaneously. [3]
Trans-carotid artery stenting involves a surgical incision at the base of the neck over the common carotid artery. It is performed under either local or general anesthesia. Wire access is obtained at that location and used to deliver the stent to the internal carotid artery. Cerebral protection is usually obtained by flow reversal - the common carotid artery is clamped, and arterial blood from the internal carotid is run through a filter and returned to a femoral vein during the highest risk portions of the procedure. [4]
The trans-radial route has been introduced as an alternative in the past few years. The vast majority of these procedures are performed under local anesthesia. In this technique, puncture of the radial artery is used to gain access to the arterial system. Wire and sheath are advanced through the aorta to the common carotid artery on the side to be treated. Flow reversal or filter cerebral protection may be used. The procedure is typically performed percutaneously. [5]
Recovery after carotid artery stenting depends not only on the presence of complications during the procedure, but also on the presence of symptoms at the time of arrival to the hospital. Asymptomatic patients typically leave the hospital in 0–1 days. The blood pressure is kept at a goal below 140 mmHg systolic. Elevated blood pressure in the 2–10 days post-operatively may lead to reperfusion syndrome.
The most feared short-term complication of any stroke prevention procedure on the carotid artery is stroke itself. Patients must still be carefully selected for surgery or stenting in order to reduce the risks related to the procedure and ensure the long-term benefit after such intervention. Other short-term complications might include bleeding, infection and heart problems such as myocardial infarction related to anesthesia.
Late complications such as recurrent stenosis may occur, and surveillance with duplex ultrasound or CT-Angiography may be performed.
The risk-reduction from intervention for carotid stenosis (stenting or endarterectomy) is greatest when the indication for intervention is symptoms (i.e., the patient is symptomatic) - typically stroke or TIA. [6] A new generation of double-layer stents is currently being developed to reduce to reduce the risk of stroke during or after the procedure. [7] There is insufficient evidence to say that stenting or endarterectomy is better for symptomatic patients.
Angioplasty and carotid stenting in patients with asymptomatic carotid atherosclerotic stenosis should not be performed except in the context of randomized clinical trials. [8]
A transient ischemic attack (TIA), commonly known as a mini-stroke, is a minor stroke whose noticeable symptoms usually end in less than an hour. TIA causes the same symptoms associated with strokes, such as weakness or numbness on one side of the body, sudden dimming or loss of vision, difficulty speaking or understanding language, slurred speech, or confusion.
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously.
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performed by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.
Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.
Vascular surgery is a surgical subspecialty in which diseases of the vascular system, or arteries, veins and lymphatic circulation, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty evolved from general and cardiac surgery and includes treatment of the body's other major and essential veins and arteries. Open surgery techniques, as well as endovascular techniques are used to treat vascular diseases. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature. Vascular surgeons often assist other physicians to address traumatic vascular injury, hemorrhage control, and safe exposure of vascular structures.
Restenosis is the recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow. Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of an artery, or other blood vessel, or possibly a vessel within an organ.
Interventional cardiology is a branch of cardiology that deals specifically with the catheter based treatment of structural heart diseases. Andreas Gruentzig is considered the father of interventional cardiology after the development of angioplasty by interventional radiologist Charles Dotter.
Cerebral angiography is a form of angiography which provides images of blood vessels in and around the brain, thereby allowing detection of abnormalities such as arteriovenous malformations and aneurysms. It was pioneered in 1927 by the Portuguese neurologist Egas Moniz at the University of Lisbon, who also helped develop thorotrast for use in the procedure.
Intermittent claudication, also known as vascular claudication, is a symptom that describes muscle pain on mild exertion, classically in the calf muscle, which occurs during exercise, such as walking, and is relieved by a short period of rest. It is classically associated with early-stage peripheral artery disease, and can progress to critical limb ischemia unless treated or risk factors are modified and maintained.
Carotid endarterectomy is a surgical procedure used to reduce the risk of stroke from carotid artery stenosis. In endarterectomy, the surgeon opens the artery and removes the plaque. The plaque forms and thickens the inner layer of the artery, or intima, hence the name of the procedure which simply means removal of part of the internal layers of the artery.
Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis.
Cerebral infarction is the pathologic process that results in an area of necrotic tissue in the brain. It is caused by disrupted blood supply (ischemia) and restricted oxygen supply (hypoxia), most commonly due to thromboembolism, and manifests clinically as ischemic stroke. In response to ischemia, the brain degenerates by the process of liquefactive necrosis.
Aortic valvuloplasty, also known as balloon aortic valvuloplasty (BAV), is a procedure used to improve blood flow through the aortic valve in conditions that cause aortic stenosis, or narrowing of the aortic valve. It can be performed in various patient populations including fetuses, newborns, children, adults, and pregnant women. The procedure involves using a balloon catheter to dilate the narrowed aortic valve by inflating the balloon.
A watershed stroke is defined as a brain ischemia that is localized to the vulnerable border zones between the tissues supplied by the anterior, posterior and middle cerebral arteries. The actual blood stream blockage/restriction site can be located far away from the infarcts. Watershed locations are those border-zone regions in the brain supplied by the major cerebral arteries where blood supply is decreased. Watershed strokes are a concern because they comprise approximately 10% of all ischemic stroke cases. The watershed zones themselves are particularly susceptible to infarction from global ischemia as the distal nature of the vasculature predisposes these areas to be most sensitive to profound hypoperfusion.
Percutaneous coronary intervention (PCI) is a non-surgical procedure used to treat narrowing of the coronary arteries of the heart found in coronary artery disease. The process involves combining coronary angioplasty with stenting, which is the insertion of a permanent wire-meshed tube that is either drug eluting (DES) or composed of bare metal (BMS). The stent delivery balloon from the angioplasty catheter is inflated with media to force contact between the struts of the stent and the vessel wall, thus widening the blood vessel diameter. After accessing the blood stream through the femoral or radial artery, the procedure uses coronary catheterization to visualise the blood vessels on X-ray imaging. After this, an interventional cardiologist can perform a coronary angioplasty, using a balloon catheter in which a deflated balloon is advanced into the obstructed artery and inflated to relieve the narrowing; certain devices such as stents can be deployed to keep the blood vessel open. Various other procedures can also be performed.
Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory disease of the blood vessels that causes abnormal growth within the wall of an artery. FMD has been found in nearly every arterial bed in the body although the most common arteries affected are the renal and carotid arteries.
Congenital stenosis of vena cava is a congenital anomaly in which the superior vena cava or inferior vena cava has an aberrant interruption or coarctation.
Transradial catheterization is an endovascular procedure or catheterization procedure performed to diagnose and treat arterial disease. Endovascular procedure can be performed achieving access in to body’s arterial system from either femoral artery, brachial artery or radial artery in the wrist. The transfemoral approach to perform cardiac catheterization has typically been more prevalent in invasive cardiology. But radial access has gained popularity due to technical advances with catheters and lower complication rates than transfemoral access. The European Society of Cardiology and the American Heart Association both support a radial-first approach in acute coronary syndrome.
Endovascular therapy (EVT), also known as neurointerventional surgery (NIS), interventional neuroradiology (INR), endovascular neurosurgery, and interventional neurology is a medical subspecialty of radiology, neurosurgery, and neurology specializing in minimally invasive image-based technologies and procedures used in diagnosis and treatment of diseases of the head, neck, and spine.
Brajesh Lal, born in 1963 in Varanasi, India, is an American of Indian origin, surgeon, and an expert in vascular disease, particularly the prevention and treatment of stroke and venous disease.