Angiography is a type of x-ray that is done to image blood vessels in various parts of the body, including the heart, brain and kidneys, so as to determine whether the vessels are diseased, narrowed, enlarged or blocked altogether. After passing a catheter through an artery leading to the body area of interest, a contrast material is injected to highlight the vessels when x-rays are taken. Angiography most commonly leads to angioplasty.
To perform an angioplasty, an GBI Radiologist makes a small nick in the skin and inserts a balloon-tipped catheter. The catheter is threaded through the artery until it reaches the site of the blockage, where the balloon is inflated, then deflated and removed. Expanding the balloon helps to restore blood flow by stretching the arterial wall, which increases the inner diameter of the artery.
Many angioplasty procedures also include the placement of a stent, a small, flexible tube made of plastic or wire mesh to support the damaged artery walls. Stents are typically placed over a balloon-tipped catheter, which is expanded, pushing the stent in place against the artery wall. When the balloon is deflated and removed, the stent remains permanently in place, acting like a scaffold for the artery.
You will be asked not to eat or drink anything after midnight on the night before your procedure. In most cases, you should take any medications that you usually take, especially blood pressure medications. These can be taken with some water in the morning before your procedure. When you schedule your procedure we will go over how to handle any medications you are currently taking. You will need to have someone drive you home after the procedure.
Narrowing or blockage in the arteries is most often caused by atherosclerosis, also called hardening of the arteries. Although it is commonly thought of as a heart disease, atherosclerosis can affect arteries anywhere in the body, including the legs and the brain. It is a gradual process in which cholesterol and other fatty deposits—called plaques—build up on the artery walls. These plaques act as barriers that limit blood flow through the arteries to tissues and organs. Other barriers to adequate blood flow include clots or plaques that break away from the blood vessel wall and become lodged in an artery.
When a blood clot, plaque or scar tissue cause an artery to become narrow or completely blocked, blood circulation is limited and the organs and tissues supplied by that artery do not receive enough oxygen.
Angioplasty and vascular stenting are commonly used to treat conditions that result when arteries throughout the body become narrowed or blocked, including:
* Peripheral vascular disease (PVD)/peripheral artery disease (PAD) (narrowing of the arteries in the legs or arms).
* Renal vascular hypertension (high blood pressure caused by narrowing of the kidney arteries).
* Hemodialysis access maintenance.
Peripheral vascular disease (PVD), also called peripheral artery disease (PAD), is a condition in which there is insufficient blood flow through the arteries to the arms or legs, causing pain, cramping or heaviness in the muscles (called intermittent claudication). Causes of PVD and PAD include atherosclerosis, scar tissue and blood clots. In patients with PVC or PAD, angioplasty may be used to open up a blocked artery in the pelvis, leg or arm. A common site is the iliac arteries of the pelvis.
Renal vascular hypertension is a condition in which one or both of the arteries that supply blood to the kidneys narrow significantly due to atherosclerosis. This reduced blood flow through the renal artery causes the kidney to release increased amounts of the hormone renin, which is responsible for regulating blood pressure. The increase in renin begins a series of chemical events in the body that result in hypertension, also called high blood pressure. Angioplasty and stenting are used to improve blood flow and reduce blood pressure.
Hemodialysis access maintenance. Patients with kidney failure must have regular hemodialysis treatments to prevent waste products from building up in the blood. Some of these patients have a graft (a synthetic material) constructed between an artery and vein in the arm so that blood can easily be withdrawn and replaced during dialysis. On average, these grafts stay open for about one year. Repeated angioplasty can help a graft stay open for as long as five years. Many patients have an arteriovenous fistula, a connection made between the artery and vein that can be used for dialysis. In some cases angioplasty may be used to help these connections work better.
Benefits:
Catheter angiography presents a very detailed, clear and accurate picture of the blood vessels. This is especially helpful when a surgical procedure or some percutaneous intervention is being considered.
Unlike computed tomography (CT) or magnetic resonance (MR) angiography, use of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example is finding an area of severe arterial narrowing, followed by angioplasty and placement of a stent.
The degree of detail displayed by catheter angiography may not be available with any other noninvasive procedure.
Risks:
You may have an allergic reaction to the dye, and this could lead to a skin reaction, a drop in blood pressure, difficulty breathing or even loss of consciousness.
There is a small risk that blood will form a clot around the tip of the catheter, blocking the artery and making it necessary to operate to reopen the vessel.
If you have diabetes or kidney disease, the kidneys may be injured when contrast material is eliminated through the urine.
Rarely, the catheter punctures the artery, causing internal bleeding. It also is possible that the catheter tip will separate material from the inner lining of the artery, causing a block "downstream."
Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.