What is a digital subtraction angiogram?

A digital subtraction angiogram is a procedure in which the doctor uses computer-assisted x-rays to see the shape and moving image of blood vessels at work.

When is it used?

This procedure may be used to study blood vessels, to recognize tumors in the vessels, pulmonary emboli (blood clots in lung), and to check the grafts implanted in heart operations, such as a coronary bypass operation.

Alternatives to this procedure are a routine angiogram or ultrasound scan. You may also choose not to have treatment, recognizing the risks of your condition. You should ask your doctor about these choices.

How do I prepare for a digital subtraction angiogram?

If you have an allergy to iodine-containing food such as shellfish or have kidney disease or kidney problems, tell the doctor.

Follow any instructions your doctor may give you. No special preparation is needed for local anesthesia.

What happens during the procedure?

You will lie down on an examining table. The doctor will use local anesthesia to numb your skin before inserting a thin tube into the desired artery or vein. The doctor will inject a contrast dye through the tube. As the dye is going through the artery, the computer-assisted x-ray system will display the artery so it is easier for the doctor to see.

What happens after the procedure?

The doctor or nurse will place a weight on the puncture site. You should lie still for up to 6 hours to permit the blood vessel to heal. After a doctor or nurse places a small dressing over the puncture site, you can go home.

You should ask your doctor what other steps you should take and when you should come back for a checkup.

What are the benefits of this procedure?

The doctor may find your problem by using a smaller amount of dye in your artery than other tests require.

What are the risks associated with this procedure?

• You may react to the dye. That reaction could include difficulty in breathing, drop in blood pressure, loss of consciousness, swelling of the skin, or other effects.

• If your kidneys are not working well, the dye may make them worse.

• The thin tube the doctor uses could damage the artery.

• Debris on the wall of the artery may become dislodged and pass down the artery, causing damage to organs the artery supplies with blood.

• Your blood vessels may not show up well enough for the doctor to make a diagnosis.

You should ask your doctor how these risks apply to you.

When should I call the doctor?

Call your doctor immediately if:

• You develop a rash.

• The puncture site bleeds.

Call your doctor during office hours if:

• You have questions about the procedure or its result.

• You want to make another appointment.