eMedicine Specialties > Dermatology > Diseases of the Vessels

Venous Insufficiency: Differential Diagnoses & Workup

Author: Robert Weiss, MD, Associate Professor, Department of Dermatology, Johns Hopkins University School of Medicine,
Coauthor(s): Craig F Feied, MD, FACEP, FAAEM, FACPh, Professor of Emergency Medicine, Georgetown University School of Medicine; General Manager, Microsoft Enterprise Health Solutions Group
Contributor Information and Disclosures

Updated: Apr 14, 2009

Differential Diagnoses

Other Problems to Be Considered

Hepatic insufficiency
Lymphedema

Workup

Laboratory Studies

• Many patients with venous insufficiency have clinically unrecognized chronic recurrent varicose thrombosis due to stasis in areas with abnormal veins.
  • Such patients may have elevated levels of the D-dimer.
  • This finding reduces the usefulness of that test for the evaluation of patients with suspected acute venous thromboembolic disease.
• Laboratory tests may be helpful in patients with venous insufficiency due to KTW disease because they can develop consumptive thrombocytopenia.

Imaging Studies

• Duplex ultrasonography is the study of choice for the evaluation of venous insufficiency syndromes. A duplex sonogram is the name given to a real-time B-mode (2-dimensional) sonographic image to which continuous-wave (CW) Doppler information is added. With this addition, the investigator can see a plot of flow velocity over time and also listen to the sound of the flow in the area of interest.
  • Color-flow duplex imaging uses the Doppler information to color code the 2-dimensional sonogram. On the image, red indicates flow in one direction (relative to the transducer), and blue indicates flow in the other direction. With the latest-generation machines, the shade of the color may reflect the flow velocity (in the Doppler mode) or the flow volume (in the power Doppler mode).
  • Color-flow systems are easier to use than gray-scale systems, but the addition of color-coded Doppler information has not been shown to increase the sensitivity or specificity of the B-mode scan in the hands of a truly skilled examiner.
  • When used to evaluate patterns of venous reflux, ultrasonography is both sensitive and specific. Ultrasonographic reflux mapping is essential for the evaluation of peripheral venous insufficiency syndromes.
  • When used to diagnose DVT, ultrasonography is not as sensitive or specific as contrast venography. Ultrasonography may fail to depict venous thromboembolism in as many as 40% of cases, especially that in the iliac veins, the pelvic veins, the transition zone between the lower thigh and the knee, and the deep veins below the knee. Nonetheless, duplex ultrasonography is the initial diagnostic imaging modality of choice in patients with suspected DVT.
• Magnetic resonance venography (MRV) is the most sensitive and specific test for the assessment of deep and superficial venous disease in the lower legs and pelvis, areas not accessible with other modalities. MRV is particularly useful because it can help in the detection of previously unsuspected nonvascular causes of leg pain and edema when the clinical presentation erroneously suggests venous insufficiency or venous obstruction.
• Direct contrast venography is a labor-intensive and invasive imaging technique. In most centers, duplex sonography has replaced this direct contrast venography in the routine evaluation of venous disease. However, the technique remains useful in difficult or confusing cases.
  • An intravenous catheter is placed in a dorsal vein of the foot, and radiographic contrast material is infused into the vein. A superficial tourniquet is placed around the leg to occlude the superficial veins and force the contrast material into the deep veins.
  • The assessment of reflux by means of direct contrast venography requires the passage of a catheter from the ankle to the groin with the selective introduction of contrast material into each segment of the vein.
  • In nearly 15% of patients undergoing venography for detection of DVT, a new thrombosis is detected shortly after a contrast venogram shows negative results. The incidence of contrast-induced DVT in patients who undergo venography for the assessment of venous insufficiency is not known.

Other Tests

• Physiologic tests of venous function are important in assessing the cause and severity of venous insufficiency. The physiologic parameters most often measured are the venous refilling time (VRT), the maximum venous outflow (MVO), and the calf muscle pump ejection fraction (MPEF).
• The VRT is the time necessary for the lower leg to become suffused with blood after the calf muscle pump has emptied the lower leg as thoroughly as possible.
  • When patients with healthy veins are in a sitting position, venous refilling of the lower leg occurs only by means of arterial inflow and requires at least 2 minutes.
  • In patients with mild and asymptomatic venous insufficiency, some venous refilling occurs by means of reflux across leaky valves. These asymptomatic patients have a VRT of 40-120 seconds.
  • In patients with significant venous insufficiency, venous refilling occurs through high-volume reflux and is fairly rapid. Patients have an abnormally fast VRT of 20-40 seconds, which reflects retrograde venous flow through failed valves in superficial and/or perforating veins. This degree of reflux may be associated with the typical symptoms of venous insufficiency. Patients often complain of nocturnal leg cramps, restless legs, leg soreness, burning leg pain, and premature leg fatigue.
  • A venous refilling time of less than 20 seconds is markedly abnormal and due to high volumes of retrograde venous flow. High-volume reflux may occur via the superficial veins, the large perforators, or the deep veins. Patients with this degree of reflux are nearly always symptomatic. If the refilling time is less than 10 seconds, venous ulcerations are so common that they are considered virtually inevitable.
• The MVO test is used to detect an obstruction to venous outflow from the lower leg, no matter what the cause. Its results are a measure of the speed with which blood can flow out of a maximally congested lower leg when an occluding thigh tourniquet is suddenly removed.
  • The advantages of MVO testing are that it is a functional test rather than an anatomic test, and it is sensitive to significant intrinsic or extrinsic venous obstruction due to any cause at almost any level.
  • MVO can be used to detect obstructing thrombus in the calf veins, the iliac veins, and the vena cava, where ultrasonography and venography are insensitive.
  • MVO can also be used to detect venous obstruction due to extravascular hematomas, tumors, and other extrinsic disease processes.
  • The disadvantage of the test is that it is sensitive only for significant venous obstruction and not for partial obstruction. It is not useful for the detection of reflux-induced venous insufficiency. A normal MVO result does not absolutely rule out DVT.
• The MPEF test is used to detect failure of the calf muscle pump to expel blood from the lower leg.
  • MPEF results are highly repeatable, but a skilled operator is required to obtain clean, meaningful tracings.
  • The patient is asked to stand on his or her tiptoes 10-20 times or to dorsiflex his or her ankle. The change in a physical parameter that reflects the blood volume in the calf is recorded as the calf muscle is pumped.
  • In patients with normal veins and a normal calf muscle pump, 10-20 tiptoe motions or ankle dorsiflexions empties the venous capacitance circuit of the calf.
  • In patients with muscle pump failure, severe proximal obstruction, or severe deep venous insufficiency, tiptoe motions or ankle dorsiflexions have little or no effect on the amount of blood remaining in the calf. Venous insufficiency due to this cause is difficult to treat.

Procedures

• The Trendelenburg test is a traditional physical examination maneuver that may help in distinguishing distal venous congestion caused by superficial venous reflux from that caused by incompetence of the valves in the deep venous system.
  • To perform the Trendelenburg test, elevate the patient's leg until all of the congested superficial veins collapse.
  • Apply direct pressure to occlude the superficial veins below the point of suspected reflux from the deep system into the superficial varicosity. Most often, the greater saphenous vein is manually occluded just below the saphenofemoral junction at the groin.
  • The patient stands with the occlusion still in place. If the distal varicosity remains empty or fills slowly, quickly remove the occluding hand or tourniquet. If the slow filling observed with occlusion is followed by rapid filling after the occlusion is removed, the principal high-pressure entry point into the superficial system is correctly identified.
  • Immediate refilling of the varicosity despite manual occlusion indicates that the principal entry point has not yet been identified or that more than 1 reflux pathway is involved.
  • Extremely rapid refilling despite occlusion of the superficial reflux pathways suggests that the valves in the deep veins may be incompetent between the groin and the level at which the reflux escapes the deep system. The result is rapid filling of the superficial system.
• If deep venous insufficiency is confirmed with results from further evaluations, the treatment options for the patient may be severely limited.

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