A venogram is a procedure that provides X-ray visualization of the veins, particularly in the lower extremities (legs). Contrast material, also known as X-ray dye, is injected that is visible on the X-ray. The contrast dye allows the doctor to evaluate the size and condition of the veins. A venogram may be used for diagnosing deep vein thrombosis (DVT), although ultrasound is usually used for this. Venography can also be used to diagnose other abnormalities.
Reasons for the procedure
A venogram is used to confirm a diagnosis of DVT and to distinguish clot formation from other venous obstructions.
Risks of the procedure
If you are pregnant or suspect that you may be pregnant, you should notify your healthcare provider. Radiation exposure during pregnancy may lead to birth defects.
Because the contrast is used, there is a risk of allergic reaction to the dye. Patients who are allergic to or sensitive to medications, contrast dye, or iodine should notify their doctor.
Patients with kidney failure or other kidney problems should notify their doctor. In some cases, the contrast dye can cause kidney failure, and it is especially important to let your doctor know if you are taking Glucophage (a diabetic medication).
Notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting.
For certain individuals, a venogram may be contraindicated. These include persons with a known allergy to contrast dye, severe congestive heart failure, and severe pulmonary hypertension.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Certain factors or conditions may interfere with the accuracy of a venogram. These factors include, but are not limited to, the following:
- The ability of the patient to remain still during the procedure
- Extreme obesity
- Severe swelling in the legs
Before the procedure
- Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
- You will be asked to sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if something is not clear.
- Notify your doctor if you have ever had a reaction to any contrast.
- You may be asked to stop eating and/or drinking for at least four hours before the procedure.
- If a sedative is given before or during the procedure, you may need to have someone drive you home afterward.
- Based on your medical condition, your doctor may request other specific preparation.
During the procedure
A venogram may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor’s practices.
Generally, the venogram follows this process:
- A pen may be used to mark various sites of pulses on the leg before the procedure. This will allow easier monitoring of the pulses after the procedure.
- After cleansing the area, an intravenous (IV) line will be inserted into a vein in your foot.
- An injection of contrast dye will be given. You may feel some effects when the dye is injected into the IV line. These effects include a flushing sensation, a brief headache, nausea, and/or vomiting. These effects usually last for a few moments. Also, let the doctor know if you are having difficulty breathing, itching of the skin, or hives.
- X-rays will be taken at timed intervals as the dye travels through the lower extremities.
- A tourniquet may be placed on the extremity to control the speed of blood flow.
- The intravenous site will be flushed with heparin/saline solution, and the needle will be removed from the vein.
- A pressure dressing will be placed over the puncture site.
After the procedure
Following the procedure, your vital signs (heart rate, breathing rate, and blood pressure) will be monitored frequently and then at intervals determined by your doctor. The peripheral pulses in your feet, as well as the temperature, color, and sensation in your legs, will be checked. The injection site will also be monitored for redness, warmth, swelling, and tenderness.
Normal activities and diet can be resumed after the procedure as directed by your doctor.
Drink plenty of fluids to prevent dehydration and to help pass the contrast dye.
Notify your doctor to report any of the following:
- Fever or chills
- Increased pain, redness, swelling, bleeding, or another drainage from the injection site
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.
