Norm of Venography (Phlebography)
Negative. Normal finding. Absence of thrombosis. No obstructions to flow or filling defects identified.
Abnormal finding. An intraluminal filling defect in the deep venous contrast column indicates deep venous thrombosis (DVT). An abrupt cutoff of a deep vein with the development of collateral circulation may also indicate the presence of DVT.
Usage of Venography (Phlebography)
Detection of site and presence of venous thrombosis of the lower extremities; radiographic guidance for insertion of peripherally inserted central catheter (PICC); used with magnetic resonance imaging for the detection and evaluation of arteriovenous malformations and vascular venous lesions.
Description of Venography (Phlebography)
Venography is an invasive, radiographic, or nuclear medicine, procedure whereby radiopaque dye or a radionuclide is injected intravenously and the lower extremities are radiographed for the DVT. Although considered to be the criterion standard for detection of deep venous thromboses, venography is similar in accuracy to newer ultrasonographic techniques for symptomatic clients. In asymptomatic clients, however, it remains superior in accuracy but higher in risk compared to ultrasonography for the detection of DVT. For initial detection of proximal DVT, venography has largely been replaced by the use of compression ultrasonography (CUS) and color duplex ultrasonography. Venography is more often reserved for detection of calf DVT, and for further testing for repeat symptoms during the first 6 months after an acute DVT.
Professional Considerations of Venography (Phlebography)
Consent form IS required.
Allergic reaction to dye (itching, hives, rash, tight feeling in the throat, shortness of breath, anaphylaxis), bacteremia, cellulitis (onset 2–12 hours; peak 12–24 hours), congestive heart failure, embolism, renal toxicity from contrast medium, thrombophlebitis, vasospasm, venous thrombosis, venipuncture-site infection.
Severe congestive heart failure; severe pulmonary hypertension; previous allergy to radiographic dye, iodine, or shellfish; pregnancy (because of the radioactive iodine crossing the blood-placental barrier); renal insufficiency.
- This test is normally performed in a radiology department.
- Have emergency equipment readily available.
- Obtain radiographic dye, heparin and saline flush solution, and a tourniquet.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- The client is positioned supine or semi-upright on the fluoroscopic table, with the weight placed on the nonexamined extremity.
- A tourniquet may be placed on the extremity to control the speed of blood flow.
- After intravenous access is established in a foot vein, radiographic dye is injected, and several rapid, sequential radiographs are taken of the extremity as the dye flows in the bloodstream. Alternatively, one may conduct a nuclear medicine study whereby a radionuclide is injected, followed by scintigraphic scanning of the extremity.
- The intravenous access site is flushed with heparin/saline solution, and the access is removed.
- Assess injection site for symptoms of dye infiltration (redness, edema, warmth, tenderness).
- Assess vital signs; peripheral pulses; and color, motion, temperature, and sensation of lower extremities every 15 minutes × 4, then every 30 minutes × 4, then hourly × 4, and then every 4 hours until 24 hours after the procedure.
Client and Family Teaching
- A feeling of warmth around the neck and face is normally felt after the injection.
- Procedure time is 1–1½ hours.
Factors That Affect Results
- Only 25% of symptomatic clients have a thrombus.
- Limitations of this procedure include poor visualization when a client has previously had a DVT in the affected extremity, intralimb contrast material dilution, and difficulties obtaining pedal venous access secondary to client characteristics.