Angiography and Venography are specialized X-ray exams of the arteries and veins to diagnose blockages and other blood vessel problems. One of the most common reasons for Angiograms is to see if there is a blockage or narrowing in a blood vessel that may interfere with the normal flow of blood through the body. Venography uses an injection of contrast material to show how blood flows through the veins. Doctors may use it to find blood clots, identify a vein for use in a bypass procedure or dialysis access, or to assess varicose veins before surgery.
First, your vascular surgeon will authorize blood tests to evaluate blood clotting ability and kidney function. Depending on the Angiogram or Venogram that is required, you may be asked to abstain from food and drink and avoid the use of anti-blood clotting medications.
A nurse or technologist will insert an intravenous (IV) line into a small vein in your hand or arm. A small amount of blood will be drawn before starting the procedure to make sure that your kidneys are working and that your blood will clot normally. A small dose of sedative may be given through the IV line to lessen your anxiety during the procedure.
The area of the groin or arm where the catheter will be inserted is shaved, cleaned and numbed with local anesthetic. The radiologist will make a small incision (usually a few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is then guided through the arteries to the area to be examined. After the contrast material is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is removed and the incision site is closed by applying pressure on the area for approximately 10 to 20 minutes (or by using a special closure device).
When the examination is complete, you may be asked to wait until the radiologist determines that all the necessary images have been obtained. A catheter angiogram may be performed in less than an hour; however, it may last several hours.
The physician will insert a needle or catheter into a vein to inject the contrast agent. Where that needle is placed depends upon the area of your body where the veins are being evaluated. As the contrast material flows through the veins being examined, several x-rays are taken. You may be moved into different positions so that the x-rays can take pictures of your veins at different angles.
You may be asked to remove some or all of your clothes and to wear a gown during the exam. You will feel a slight pin prick when the needle is inserted into your vein for the intravenous line (IV) and when the local anesthetic is injected. The arteries have no sensation. Most of the sensation is at the skin incision site, which is numbed using local anesthetic. As the contrast material passes through your body, you may get a warm feeling.
You may have a metallic taste in your mouth and your arm or leg may feel like it is getting numb or “falling asleep.” After the test is complete, this feeling will go away.
You must hold very still and may be asked to keep from breathing for a few seconds while the X-ray picture is taken to reduce the possibility of a blurred image. The technologist will walk behind a wall or into the next room to activate the X-ray machine.
When the examination is complete, you may be asked to wait until the radiologist determines that all the necessary images have been obtained. A Venogram takes between 30 and 90 minutes to perform. Fluids will be run through your IV to remove the contrast material from your veins and you will be instructed to drink a lot of fluids for the next day. After the catheter is removed, a bandage will be placed on the IV site. You will be observed for any signs of complications, such as bleeding from the injection site, infection or an allergic reaction.
After your procedure, it is important that you lie still in order to prevent bleeding. Patients are usually monitored for about 4 hours after the procedure.