(also known as renal arteriogram)
An angiogram is a picture of the blood supply to an organ of the body obtained using x-ray equipment. A picture of the blood supply to the kidneys is called a renal angiogram. To obtain a picture, a radio-opaque dye is injected into the bloodstream via the groin or forearm. As the dye reaches the kidneys, the blood vessels of the kidneys are shown up when an x-ray picture is taken.
When kidneys stop working properly, doctors want to find out why. A renal angiogram will show the medical team if the reason for kidney failure is related to problems occurring with the blood supply to the kidneys. For people who want to donate a kidney, it is important to make sure that their kidneys are suitable for donation and that the kidney left after the operation will be able to go on working.
Before you can have a renal angiogram, you will be asked for your written consent. In order to obtain consent the doctor will explain the test, what it is for, what happens and the risks and benefits of having the test and answer any questions that you or your family may have about the test. Please tell the doctor if you take warfarin or have asthma.
You will be asked not to eat for six hours prior to the angiogram but you may drink. You may be prescribed a sedative to help you relax if this is necessary.
As the dye is usually injected into the bloodstream through the groin, it is necessary to shave this area. This is often carried out by the nursing staff, but you may do it yourself if you wish.
You will be required to wear a theatre gown and paper, disposable underwear.
Angiograms are performed in the X-ray Department. They can be performed as an inpatient or outpatient procedure. If you are an outpatient you will be asked to come to the main ward or a day case ward in the morning where a bed will be available for you. From the ward, you will be taken to the X-ray Department.
In X-ray, in the investigation room, you will be asked to lie on your back on a table. The doctor who will perform the test will clean your groin with an antiseptic solution. Sterile green towels are then placed over the area and a pain killing injection will be given to numb the skin of the groin. The doctor will ask you if you can feel the area before proceeding. At this point the doctor will use a special needle to introduce a narrow tube (catheter) into the artery in your groin. This tube is fed into the artery under x-ray guidance until it reaches the point at which the dye (contrast medium) can be injected through the tube into the blood supply of the kidneys.
You may have a feeling of warmth as the dye is injected, starting at the tip of the catheter and going around your body. You may briefly feel as if you are passing water, however, this is a momentary sensation.
Once the dye has been injected a series of x-ray pictures of the kidneys will be taken by the radiographer. When this is completed, the catheter is carefully removed and pressure is applied to the groin site for about 10 minutes to prevent bleeding. A dressing will be applied to the site.
If the angiogram has shown a narrowing of the renal artery, you may be asked if you wish to proceed to have an angioplasty. This is a very similar procedure where a catheter is inserted into the artery. The catheter has a small balloon on the end of it, which is inflated, at the narrowing in the artery in order to enlarge the artery by gently stretching it. Some discomfort can be felt. However, the improved blood flow that this allows may lead to an improvement of kidney function and/or blood pressure. You will be asked about proceeding to angioplasty as part of the consent procedure if it is appropriate. Some people will have the angioplasty as a second procedure at a later date if required.
Once the test has been completed and it is safe for you to leave X-ray, you will return to the ward where you will be asked to remain in bed for between 4 and 6 hours, keeping your leg relatively still. You will be advised to press on the wound dressing when you sneeze, cough or do move. Your blood pressure and pulse will be measured frequently and the dressing and groin checked for any sign of bleeding or swelling.
You may be asked to drink to flush out the dye from your system. It may be the next morning before you can use your leg properly.
The most common problem associated with an angiogram is bruising, oozing or bleeding from the puncture site where the catheter was inserted. This is why you stay on bed rest after the procedure and nursing staff check the groin area regularly. The area will be bruised, swollen and possibly painful for a few days.
You should not drive or lift heavy objects for 2 days after the procedure after which time your groin should have healed.
The dye may affect your kidney function causing a temporary rise in creatinine. For this reason you are asked to drink plenty in order to flush the dye from your bloodstream.
If you are an outpatient, the results will be explained to you by your doctor at your next outpatient’s appointment or earlier if indicated.
If you are in hospital, the results should be available almost immediately as the radiologist will write a report of the investigation in your medical notes.