What is a renal angiogram?
A renal angiogram is an imaging test to look at the blood vessels in your kidneys. Your doctor can use it to look at the ballooning of a blood vessel (aneurysm), narrowing of a blood vessel (stenosis), or blockages in a blood vessel. He or she can also see how well blood is flowing to your kidneys.
For the test, the radiologist injects a contrast dye into the kidney. The radiologist uses X-ray images to watch the dye as it flows through the blood vessels in the kidneys.
X-rays use a small amount of radiation to create images of your bones and internal organs. X-rays are most often used to detect bone or joint problems, or to check the heart and lungs. A renal angiogram is one type of X-ray.
Fluoroscopy is often used during a renal angiogram. Fluoroscopy is a kind of X-ray "movie."
Why might I need a renal angiogram?
You may need a renal angiogram to help your healthcare provider find problems in the blood vessels of your kidneys. These problems may include:
- Bulging of a blood vessel (aneurysm)
- Narrowing of a blood vessel (stenosis)
- Spasm of a blood vessel (vasospasm)
- An abnormal connection between arteries and veins (arteriovenous malformation)
- Blood clot (thrombosis)
- Blockage (occlusion)
- High blood pressure in the kidneys (renovascular hypertension)
You may also need a renal angiogram to help your provider diagnose:
- Bleeding (hemorrhage)
- Complications from a kidney transplant
- Chronic kidney disease
- Kidney failure
Your provider may also use a renal angiogram to deliver medicines directly to the kidneys. This might be to stop bleeding or to treat kidney cancer.
You may need a renal angiogram if another test such as a CT scan did not give your provider enough information.
Your healthcare provider may have other reasons to recommend a renal angiogram.
What are the risks of a renal angiogram?
You may want to ask your healthcare provider about the amount of radiation used during the test. Also ask about the risks as they apply to you.
Consider writing down all X-rays you get, including past scans and X-rays for other health reasons. Show this list to your provider. The risks of radiation exposure may be tied to the number of X-rays you have and the X-ray treatments you have over time.
Tell your healthcare provider if you:
- Are pregnant or think you may be pregnant. Radiation exposure during pregnancy may lead to birth defects.
- Are allergic to or sensitive to any medicines, contrast dye, or iodine. Because contrast dye is used, there is a risk for allergic reaction to the dye.
- Have kidney failure or other kidney problems. In some cases the contrast dye can cause kidney failure. You are at higher risk for this if you take certain diabetes medicines.
Possible complications of a renal angiogram include:
- Injury to nerves
- Blood clot (embolus)
- Swelling caused by a collection of blood (hematoma)
- Temporary kidney failure
- Damage to an artery or an artery wall. This can cause blood clots.
You may have other risks depending on your specific health condition. Be sure to talk with your provider about any concerns you have before the procedure.
Certain things can make a renal angiogram less accurate. These include:
- Having contrast dye still in your body from a recent imaging test
- Gas or stool in the intestines
How do I get ready for a renal angiogram?
- Your healthcare provider will explain the procedure to you. Ask him or her any questions you have about the procedure.
- You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if anything is not clear.
- You'll be asked to not eat or drink liquids (fast) before the procedure. Your healthcare provider will tell you how long to fast. It might be several hours or overnight.
- Tell your provider if you are pregnant or think you may be pregnant.
- Tell your healthcare provider if you are allergic to contrast dye or iodine.
- Tell your healthcare provider if you are sensitive to or are allergic to any medicines, latex, tape, or anesthetic drugs (local and general).
- Tell your provider about all medicines you are taking. This includes prescriptions, over-the-counter medicines, and herbal supplements.
- Tell your healthcare provider if you have had a bleeding disorder. Also tell your provider if you are taking blood-thinning medicine (anticoagulant), aspirin, or other medicines that affect blood clotting. You may need to stop these medications before the test.
- You may get medicine to help you relax (sedative) before the test. You may also get medicine that slows down how much saliva you make (anticholinergic medicine). This slows down how much acid your stomach makes and slows down your digestive tract. You may notice that your mouth feels dry.
- Depending on the site used for injection of the contrast dye, the recovery period may last up to 12 to 24 hours. You may need to spend the night.
- You may need a blood test before the procedure to see how long it takes your blood to clot. You may also need other blood tests.
- Follow any other instructions your provider gives you to get ready.
What happens during a renal angiogram?
You may have a renal angiogram as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your healthcare provider's practices.
Generally, a renal angiogram follows this process:
- You will be asked to remove any clothing, jewelry, or other objects that might get in the way of the test.
- You will be given a gown to wear.
- You will be asked to empty your bladder before the test.
- You will lie on the X-ray table.
- An intravenous (IV) line will be started in your arm or hand.
- You will be connected to an EKG monitor. It will record the electrical activity of your heart during the test. Medical staff will watch your heart rate, blood pressure, and breathing rate during the test.
- The radiologist will check your pulses below the injection site for the contrast dye. He or she will use a marker to note them. This is so that staff can check the circulation to the limb below the site after the test.
- The doctor will shave the skin in an area of your groin. He or she will clean the skin and inject local pain medicine. The doctor will put a needle into an artery in your groin. Sometimes an artery in the elbow area may be used instead. If the elbow site is used, a blood pressure cuff will be put on your arm below the IV site. It will be inflated to keep the contrast dye from going into your lower arm.
- The doctor will put a long thin tube (catheter) into the artery. He or she will move the catheter into the aorta near the renal arteries. The doctor will use fluoroscopy to see where the catheter is.
- The doctor will inject the contrast dye. You may feel a flushing sensation, a salty or metallic taste in the mouth, a brief headache, or nausea or vomiting. These effects usually last for a few moments.
- Tell the radiologist if you have trouble breathing, or if you have sweating, numbness, or heart palpitations.
- The doctor will take several sets of X-rays pictures. The first set shows the arteries. The second set shows the blood flow in the capillaries and veins.
- Depending on the study being done, you may need more injections of contrast dye.
- Once the test is done, the doctor will remove the catheter. He or she will put pressure on the site to keep the artery from bleeding.
- After the bleeding stops, he or she will put a dressing on the site. The doctor may put something heavy on the site for a period of time. This will help stop bleeding and keep blood from collecting (hematoma) at the site.
What happens after a renal angiogram?
You will be taken to the recovery room. A nurse will watch your vital signs and the injection site. He or she will check the circulation and sensation in the leg where the catheter was used.
You will need to lie flat in bed for several hours after the test. The leg or arm used for the injection site will be kept straight for up to 12 hours.
You may be given pain medicine to ease pain or discomfort from the injection site or from having to lie flat and still.
You will be told to drink water and other fluids to help flush the contrast dye from your body.
When you leave the recovery room, you may go to a hospital room or be sent home. If you had the test done as an outpatient, you will need to have someone drive you home.
You may go back to your usual diet and activities after the test, unless your healthcare provider tells you otherwise.
Once at home, you should watch the injection site for bleeding. A small bruise is normal. So is an occasional drop of blood at the site.
You should watch the leg or arm for changes in temperature or color, pain, numbness, tingling, or loss of movement.
Drink plenty of fluids to help the contrast dye leave your body. Fluids will also keep you from getting dehydrated.
You may not be able to do any strenuous activities or take a hot bath or shower for a period of time after the test.
Tell your healthcare provider if any of these occur:
- Fever or chills
- Increased pain, redness, swelling, or bleeding or other fluid draining from the groin injection site
- Coolness, numbness, tingling, or other changes in the arm or leg
Your healthcare provider may give you other instructions, depending on your situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- The risks and benefits of the test or procedure
- When and where you are to have the test or procedure and who will do it
- When and how will you get the results
- How much will you have to pay for the test or procedure