What is a renal venogram?
A renal venogram is an imaging test to look at the veins in and around your kidneys.
Your healthcare provider may also use the test to find out what is causing your high
blood pressure or whether there is a blood clot or tumor blocking your renal vein.
If the reason for the test is suspected renal hypertension, the radiologist will take
blood samples from the vein.
This test is done by a radiologist who is a doctor that specializes in radiology.
For the test, the radiologist injects a contrast dye into the vein of your kidney.
They use X-ray images to watch the dye as it flows through the blood vessels in the
X-rays use a small amount of external radiation to create images of your body, its
organs, and other internal structures. A renal venogram is one type of X-ray.
Fluoroscopy is used during a renal venogram. Fluoroscopy is a kind of X-ray movie
that shows organs in motion.
During the test, the radiologist may also take a blood sample (renin assay) from each
vein in your kidneys. The radiologist will see how much of a certain enzyme (renin)
is in each sample. This can help them find what is causing your high blood pressure.
Why might I need a renal venogram?
You may need a renal venogram to help your healthcare provider find problems in the
renal vein or with blood flow in your kidneys. These problems may include:
Your healthcare provider may have other reasons to recommend a renal venogram. Talk
with your healthcare provider about the reason for your test.
What are the risks of a renal venogram?
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
Possible complications of a renal venogram include:
You should not have renal venography if you have a severe blockage (thrombosis) in
the large vein that brings blood from your lower body to your heart (inferior vena
cava) or a blockage in the renal vein.
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 venogram less accurate. These include:
Having oral contrast still in your body from a recent imaging test such as a computed
tomography (CT) scan, barium enema or barium swallow (upper GI) X-ray
Gas or stool in the intestines
How do I get ready for a renal venogram?
Your healthcare provider will explain the procedure to you. Ask them any questions
you have about the procedure.
You will 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.
Follow any directions you are given for not eating or drinking before the procedure.
If your provider plans to take a blood sample during the test, you will need to cut
back on the amount of salt you eat before the procedure.
Tell your healthcare provider if:
You are pregnant or think you may be
You are allergic or sensitive to contrast dye or iodine as well as any medicines,
latex, tape, or anesthesia (local and general).
Also tell your healthcare provider:
About all medicines you are taking. This includes prescriptions, over-the-counter
medicines, and herbal supplements.
If you have had a bleeding disorder or are taking blood-thinning medicine (anticoagulant),
aspirin, or other medicines that affect blood clotting. You may need to stop these
medicines before the test.
You may get medicine to help you relax (sedative) before the test. You will need to
have someone drive you home afterward.
Follow any other instructions your provider gives you to get ready.
What happens during a renal venogram?
You may have a renal venogram as an outpatient or as part of your stay in the hospital.
The way the test is done may vary depending on your condition and your healthcare
Generally, a renal venogram follows this process:
You will be asked to remove your jewelry or other objects that may get in the way
of the test
If you are asked to remove clothing, you will be given a gown to wear.
An intravenous (IV) line will be started in your arm or hand.
You will lay on the X-ray table.
The nurse or technician will shave the skin in an area of your groin. They will clean
the skin and inject local pain medicine. The radiologist will put a needle into a
vein in your groin. This will be used to inject the contrast dye.
The radiologist will check your pulses below the injection site for the contrast dye.
They will use a marker to note them. This is so that staff can check the circulation
to the leg after the test.
The radiologist will put a long thin tube (catheter) into the vein. They will move
the catheter until it reaches the renal vein. The radiologist will use fluoroscopy to
see where the catheter is.
The radiologist will inject the contrast dye into the catheter. 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 radiologist will take X-ray pictures. They will be able to see the X-rays on a
Your radiologist may take a blood sample from the vein in your kidney and the IV in
your arm or hand.
Once the test is done, the radiologist will remove the catheter. They will put pressure
on the site to keep it from bleeding.
After the bleeding stops, they will put a dressing on the site. The radiologist 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 venogram?
You will be taken to the recovery room. A nurse will watch your vital signs and check
the injection site. They will also check the circulation and sensation in the leg
where the catheter was used.
You will need to lie flat in bed for at least 2 hours. Once your vital signs are stable
and your injection site dressing is clean and dry, you will be taken to your hospital
room or sent home.
You may be given pain medicine to ease pain or discomfort from the injection site
or from having to lie flat and still.
Once at home, watch the injection site for bleeding. A small bruise is normal. So
is an occasional drop of blood at the site.
You should also watch the leg where the catheter was inserted for changes in temperature
or color, pain, numbness, tingling, or loss of movement.
It's important to 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
Coolness, numbness, tingling, or other changes in the 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
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how you will get the results
Who to call after the test or procedure if you have questions or problems
How much you will have to pay for the test or procedure