A catheter angiography is a medical test in which a thin plastic tube — a catheter — is inserted through a small incision in the skin. Contrast material is inserted through the tube and into a blood vessel, and X-rays are used to capture images of the blood vessel. This procedure is used to study blood vessels in the brain, heart, lungs, kidneys, abdomen, neck, pelvis and legs. A catheter angiography is performed for a number of reasons, a few of which include the identification of possible disease and the location of aneurysms in the aorta, finding small aneurysms in the brain and detecting disease in the arteries that lead to the kidneys.
This procedure is done on an outpatient basis. Blood is taken to make sure that the kidneys are working properly and that the blood clots normally. A small incision is then made in the skin, and a catheter the size of a spaghetti noodle is guided into the artery and to the area of attention. Contrast material is inserted into the catheter, and the X-rays are taken.
On X-rays, bones appear white, air appears black, and soft tissue appears in various shades of gray. The contrast material will make the blood vessel appear bright white and easy to see. After the X-rays have been completed, the catheter is removed, and the incision is closed either by applying pressure to the incision or with the use of a special device. The catheter angiography takes anywhere from one hour to several hours. The results are interpreted by a radiologist, who sends a report to the patient's primary physician.
During the procedure, the patient will feel only a slight prick of the needle when the intravenous line is inserted into the vein. A sting might be felt when the local anesthetic is injected. The catheter in the blood vessel will not be felt, although there will be a warm or slight burning sensation when the contrast material is injected into the catheter. The patient will have to lie flat for several hours. Any pain, swelling or bleeding at the site of the catheter entry should be reported to a doctor, nurse or medical technician.
There are benefits and risks to this procedure. The benefits include the fact that catheter angiography can rule out the need for surgery, gives detailed and accurate images of blood vessels and can combine both diagnosis and treatment during the same procedure. One risk is a small chance of cancer because of the exposure to radiation, although the benefit of the diagnosis often outweighs the risk. Other risks include skin damage if a large amount of contrast material leaks under the skin where the catheter enters, a safety risk to pregnant women and the rare chance that the catheter could puncture the artery.
Not everyone is a good candidate for a catheter angiography. Patients who have diabetes or diminished kidney function are not considered to be good candidates. Patients who are allergic to contrast materials or who have a tendency to bleed are also not considered to be good candidates for the procedure.