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Angiography
What is angiography?
Angiography is a diagnostic procedure to obtain x-ray images of your arteries and veins to define narrowing, blockages and other problems that may be interfering with the flow of blood through them.
An angiographic procedure involves the physician threading a very thin catheter — a flexible, hollow tube about the diameter of a strand of spaghetti — through your blood vessels in order to inject a medical dye that will allow him or her to visualize the blood vessels.
During this time, the doctor will be able to observe the position of the catheter and the dye's dispersion with a fluoroscopy unit — an x-ray unit that provides real-time images. Essentially, with the dye spreading throughout available space within the artery or vein, the procedure yields a silhouette image of the vessels, showing any narrowing (called stenosis), blockage (often referred to as occlusion), aneurysm or malformation within the vessel and affecting the flow of blood.
Developed as a technology in the 1960s, today angiography is applied to vascular problems throughout the body, including the carotid artery in the neck, the renal arteries serving the kidneys, the aorta in the abdomen and the blood vessels in the legs.
Connecticut Surgical Group has extensive experience in endovascular (within the blood vessels) procedures. When necessary, they work closely with a team of experienced interventional radiology surgeons to ensure that patients receive the diagnosis and treatment that best fits their medical problems.
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What are the conditions or symptoms that would call for angiography?
The build-up of plaque within an artery with the result of narrowing the channel and impeding blood flow is called atherosclerosis and can occur in areas throughout the body. In this context, the symptoms that may lead to an angiography procedure can vary.
- In cases of suspected carotid artery disease, the first symptoms may be transient ischemic attacks (TIAs), or temporary symptoms warning of risk of impending stroke. Signs of TIAs can include sudden weakness or paralysis in your face or an arm or leg, sudden loss of coordination, slurred speech, difficulty understanding others and sudden loss of vision. These transient symptoms reflect narrowing or impending blockage of the arteries leading up the sides of your neck to supply blood to the brain. Blockage of blood to the brain precipitates stroke.
- For renal artery problems, elevated blood pressure or signs of kidney failure can be indications that the arteries supplying blood to one or both kidneys are experiencing narrowing or blockage.
- In instances of abdominal aortic problems, the doctor may be looking for a suspected aneurysm, an abnormal sac extending outward at a weak point in the vessel's wall. Swelling with blood, an aneurysm carries a dangerous risk of bursting, leading to uncontrolled, frequently fatal internal bleeding.
- For disease involving blood vessels in the lower extremities, systems are likely to include claudication — pain upon walking or standing — as well as development of ulcers, or wounds that resist healing due to lack of blood supply.
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What are the alternatives to angiography?
Increasingly, techniques of magnetic resonance angiography (MRA) and computerized tomographic angiography (CTA) are being developed and refined to serve as non invasive alternatives to conventional angiography.
The results from MRA's and CTA's can be quite useful in visualizing a stenosis or occlusion. However, conventional angiography remains an accurate imaging option possible for planning surgery or follow-up of endovascular treatment.
In some cases, your doctor may be able to perform an angioplasty or thrombolytic treatment in the same procedure as the angiographic test. Angioplasty is a treatment procedure in which a tiny medical balloon is inserted through the catheter to the site of a stenosis and inflated to widen the narrowed section of artery. For more information on angioplasty, click here. Thrombolysis is the delivery of clot-busting drugs to the site of an occlusion to dissolve it.
In any event, an angiography test will be done only after all other avenues of information gathering have been utilized, including traditional x-rays, ultrasound imaging and careful physical evaluation. As noted above, angiography represents the most accurate imaging techniques when planning surgery or angioplasty.
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What may happen as a result of an angiographic procedure?
Angiography yields an extremely accurate image of the condition of the blood vessels in question, and can lead to decisions as to whether to rely on medical therapy, plan surgical reconstruction of the vessels in question, or consider endovascular treatments such as angioplasty.
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What happens in the procedure?
Angioplasty is usually done on an outpatient or day-surgery basis. A specially trained physician will be performing your procedure, assisted by a technician and a nurse. You'll most likely remain awake during your procedure, with a sufficient amount of sedative to keep you comfortable. You'll receive local anesthetic at the site through which the catheter will be introduced — usually the femoral artery at a point just below the groin (this area will be shaved and sterilized before the incision is made). Another location sometimes used is a blood vessel in the arm.
The procedure will usually take place in the angiography unit, where you will lie on your back on a table flanked by a "C-arm" fluoroscopic machine and monitors on which the radiologist can observe the images it generates. Most of the time, the room will be kept somewhat dark to make it easier for the images on the monitors to be seen.
The catheter will thread through your blood vessels to the targeted location, being guided by the fluoroscopic images on the monitors. You may at some point be asked to breath or cough to assist in movement of the catheter, but overall it is important that you lie completely still.
Through the catheter, the dye is injected. As the dye enters your blood vessels it will spread to provide a silhouette image of the shape of your artery or vein — any narrowing from a stenosis, enlargement from an aneurysm or other abnormality will be apparent. Images will be recorded for a permanent record.
Occasionally during the procedure you may feel some minor, temporary sensations — a slight stinging as the pain medication is first injected, warmth when the dye is first injected, a brief headache.
Usually, the procedure takes between one and three hours, depending on where the targeted location is what kind and how many images need to be taken, and whether or not an intervention is performed simultaneously. Once the catheter is withdrawn, your nurse will apply pressure for 10 to 20 minutes to the spot where the catheter was inserted to prevent bleeding and give blood time to clot at the site.
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What should I do to prepare for my angiography procedure?
You should expect to have a consultation with your doctor or nurse a day or two before your procedure. You should be sure to tell them if you are pregnant, have asthma, have a bleeding problem or are allergic to iodine (the substance used in the dye), to medications or to any other substance, even shellfish.
You should not eat or drink for four to eight hours before your procedure.
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What happens following the procedure?
You will be kept in the recovery area for six to eight hours. If your catheter was inserted through your femoral artery, during this time, it is important for you to keep your leg straight to prevent the incision site from bleeding. If your insertion was through your arm, you should avoid having your blood pressure measured in that arm or giving blood from that arm for three or four days. You should let your nurse know if you experience any bleeding, swelling or pain.
You should make certain you have a family member or friend available to drive you home from the hospital, as you cannot drive yourself.
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What are the risks associated with the procedure?
Overall, angiography is a very safe test, but like any medical procedure there are some small risks associated with undergoing it. Most often, any problems emerge within two hours following the procedure.
- Allergic reaction to the iodine used to make up the medical dye, or to the anesthesia used. This can range from mild itching to severe difficulties breathing. This is why it is important to let your medical team know of any allergies
- A slight risk of damage to an arterial wall, or of dislodging a blood or piece of plaque from an arterial wall that could block an artery and cause damage to a organ such as the brain or an arm or leg
- Possible formation of a blood clot at the tip of the catheter, forming an occlusion.
- Possible excessive bleeding at the insertion point.
- Injury to the kidneys, or worsening of an existing kidney problem as the medical dye is excreted from the body
- A slight risk of injury from radiation. Modern technology uses very low levels of radiation, and lead shielding is also used when appropriate for areas not being imaged.
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How should I evaluate the risks and benefits of an angiography procedure?
As with any well-proven medical procedure, a small level of risk exists. Generally, if you have a vascular problem with the likelihood of affecting your health, including loss of a limb or even your life, the benefits of an angiography procedure far outweigh the risks.
Angiography offers the most detailed and most accurate images of the vascular system, and is important in defining the seriousness of a problem and providing the information for dealing with it.
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For additional information:
You can find additional information about angiography at web sites sponsored by government agencies, societies and healthcare institutions. It should perhaps be noted that the World Wide Web is open to many sources posting questionable information and promises, and you are encouraged to seek information from established, reputable organizations.
Likely sources include:
Radiology Info
www.radiologyinfo.com
The Society of Interventional Radiology
www.sirweb.com
The Vascular Disease Foundation
www.vdf.org
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