INTRODUCTION — Severe clinical manifestations of chronic venous disease, including edema (which can be unilateral), skin changes, and venous ulceration, are often sufficient to establish a diagnosis of chronic venous insufficiency. However, objective testing may be needed to confirm the diagnosis, determine the etiology (reflux, obstruction, or reflux and obstruction), localize the anatomic site and severity of disease, or identify coexisting peripheral artery disease.
Diagnostic testing identifies patients with venous pathology who may benefit from vein ablation treatments, which are effective in controlling vein-related symptoms and decreasing the incidence of recurrent ulceration in those with superficial venous reflux.
The diagnostic tests available to evaluate the patient with suspected chronic venous insufficiency are reviewed. The pathophysiology, clinical manifestations, and treatment of this disorder are discussed separately. (See "Pathophysiology of chronic venous disease" and "Clinical manifestations of lower extremity chronic venous disease" and "Overview of lower extremity chronic venous disease" and "Medical management of lower extremity chronic venous disease" and "Techniques for endovenous laser ablation for the treatment of lower extremity chronic venous disease" and "Techniques for radiofrequency ablation for the treatment of lower extremity chronic venous disease".)
APPROACH TO THE PATIENT — Localized lower extremity edema and characteristic skin pigmentation strongly support the diagnosis of venous hypertension (picture 1). The history and physical examination are sufficient in many cases for eliminating systemic causes of venous hypertension (eg, hypervolemia, heart failure). (See "Clinical manifestations of lower extremity chronic venous disease" and "Clinical assessment of chronic wounds", section on 'Differentiation of chronic ulcers' and "Clinical manifestations and evaluation of edema in adults".)
A venous duplex ultrasound examination can confirm the presence of venous obstruction or valvular incompetence as the cause of venous hypertension and is used for planning venous ablation procedures [1-3] but is not necessary in all cases of suspected venous insufficiency where intervention is not being considered. (See 'Duplex ultrasonography' below.)
Duplex ultrasonography is indicated in the following clinical situations:
●If a clinical diagnosis of venous insufficiency or obstruction cannot be established but symptoms are strongly suggestive.
●In patients with signs of chronic venous disease but whose symptoms are questionably related to the venous disease.
●In atypical cases, such as an unusually early age of onset (<40 years) of symptoms, or following trauma.
●In cases of ulceration. Patients with ulceration due to superficial venous reflux may benefit from venous ablation procedures. Significantly decreased ulcer recurrence rates have been found with removal or ablation of greater or small saphenous veins [4].
●In patients with clinically suspected venous disease who do not respond to standard conservative measures. (See "Medical management of lower extremity chronic venous disease".)
Patients with venous insufficiency and ulceration may have concurrent arterial disease, which is important to identify (table 1). Measurement of the ankle-brachial index (ABI) can determine if peripheral artery disease is present. (See 'Ankle-brachial index' below.)
Other noninvasive tests are available to assess the presence and severity of venous reflux, such as air plethysmography and photoplethysmography; however, these are not widely used given the availability and utility of venous duplex ultrasonography.
DIAGNOSTIC TESTS
Duplex ultrasonography — Duplex ultrasonography has essentially replaced conventional catheter-based venography (ascending, descending) for the evaluation of most venous disorders because it is accurate, reproducible, noninvasive, and inexpensive [5-7]. The diagnosis of chronic venous disease is confirmed by the presence of venous reflux, which is diagnosed by duplex ultrasound by duration of retrograde or reversed flow (>500 ms for superficial or perforating veins, >1000 ms for deep veins) [5,8,9].
Duplex ultrasonography combines real-time B-mode imaging of the deep and superficial veins with Doppler assessment of blood flow. Pulsed or color Doppler identifies vessels and the presence and direction of blood flow and is used to detect venous reflux or venous obstruction (absence of venous flow) and identify its anatomic location [2,10]. Combining real-time B-mode ultrasonography with directional pulsed Doppler provides complementary information about anatomic structures and flow patterns [7,11-14]:
●In B-mode imaging, a real-time ultrasound transducer encased in a probe rapidly and automatically sweeps an ultrasound beam over the area to be imaged, constructing an image from the reflected wave [11]. B-mode ultrasonography can identify blood vessels as well as other anatomic structures that can produce pain or swelling and mimic venous disease, such as popliteal (Baker) cyst, hematoma, arterial aneurysm, and other soft tissue masses [15,16]. (See "Popliteal (Baker's) cyst" and "Popliteal artery aneurysm".)
●Doppler imaging detects relative motion between the source of the signal and the reflector of the signal. The sources of the reflected signals in peripheral vascular studies are the red blood cells moving in the vessels. Flow analysis can be performed by listening to the audible signal or by recording the spectral analysis of the signal. A computer analysis of the spectral display then determines the flow velocity, direction, and characteristics of flow (laminar versus turbulent). (See "Noninvasive diagnosis of upper and lower extremity arterial disease", section on 'Duplex ultrasound'.)
For detecting proximal (above-knee) venous obstruction, B-mode imaging assesses the compressibility of the vein. Normal veins collapse with the application of pressure using the ultrasound probe; thrombosed veins do not collapse. Duplex examination of the lower extremity can also be used to predict if there is more proximal obstruction, such as iliac vein stenosis, by looking at the common femoral vein waveforms, which should be phasic and vary with respiration. If the waveform is blunted or flat without respiratory variation, a more proximal venous obstruction should be suspected [17]. When duplex ultrasonography is compared with ascending venography for a diagnosis of venous obstruction, sensitivity ranges from 86 to 96 percent and specificity ranges from 80 to 100 percent [16,18-21]. (See "Clinical presentation and diagnosis of the nonpregnant adult with suspected deep vein thrombosis of the lower extremity".)
Duplex ultrasonography is also the standard for assessing venous reflux in the great and small saphenous veins (SSVs) as well as accessory saphenous veins (41 percent of people have anterolateral saphenous vein, 95 percent of people have a posterior thigh extension of the SSV [22], and 70.4 percent of people have an intersaphenous vein [23], deep veins, and perforator veins, each of which need to be evaluated by duplex to fully treat the patient [12,24,25]). To detect reflux, the patient is usually examined upright and non-weight-bearing for the extremity being examined [8,26]. Blood pressure cuffs are placed on the thigh, calf, and above the ankle, and the veins are imaged with B-mode ultrasound. The blood pressure cuffs are serially inflated to occlude venous flow and then rapidly deflated to assess for reflux with the pulsed Doppler component of the duplex scanner. A reflux time that is >500 ms in duration is abnormal for superficial or perforating veins (>1000 ms for deep veins) and indicates valvular insufficiency at that level [8]. One study of 300 limbs found that velocity and peak flow at the peak of reflux correlated better with clinical severity compared with the reflux time [27].
Duplex ultrasonography is more sensitive and specific than descending venography in predicting the clinical severity of venous insufficiency. In a study of 56 limbs, sensitivities were 77 versus 55 percent and specificities 85 versus 41 percent for ultrasound and phlebography, respectively, for the most severe clinical grade of venous insufficiency [28].
Venography
Cross-sectional — The role of multidetector computed tomographic (MDCT) venography and magnetic resonance (MR) venography in the management of chronic venous disease is not well defined, and their impact on patient outcomes has not been documented [29-34]. While these imaging modalities can provide clear cross-sectional images of the deep venous system, including infrainguinal areas not accessible to ultrasonography, less expensive imaging modalities that do not require the use of injectable contrast continue to be preferred as the first diagnostic imaging test. For patients who have signs of venous insufficiency but normal or equivocal Doppler ultrasonography findings, MDCT and MR venography should be considered. In certain situations, these newer imaging modalities may be helpful in identifying treatable pathology and planning surgical interventions for patients with chronic venous disease. (See "May-Thurner syndrome", section on 'CT/MR venography'.)
Catheter-based — Conventional catheter-based venography (ascending, descending) is rarely needed to make a diagnosis of chronic venous disease but is performed to confirm a diagnosis of venous outflow obstruction prior to intervention. Venography is invasive and associated with a small incidence of deep vein thrombosis and other complications related to intravenous contrast administration. (See "Prevention of contrast-associated acute kidney injury related to angiography", section on 'Epidemiology' and "Prevention of contrast-associated acute kidney injury related to angiography".)
Other tests of vein function
Air plethysmography — Air plethysmography (APG) is a noninvasive physiologic examination that measures relative volume changes in the limb in response to postural changes and muscular activity. The test is more typically used by clinicians who perform large numbers of interventional venous procedures as a means to assess the hemodynamic results of venous interventions, or as a research tool.
APG measures pressure changes in the cuff, which are translatable to volume changes within the leg. The venous volume is measured and used to calculate a venous filling index (VFI). Changes in volume are measured by air displacement within a polyurethane cuff that is wrapped around the calf and inflated to a preset pressure (figure 1). The test begins with the patient supine. The limb being evaluated is elevated to drain the venous system. Once the venous system is emptied, the leg volume is recorded and the patient is asked to stand, after which the volume is recorded again. The difference in the recorded leg volume is the functional venous volume. The time needed to fill 90 percent of the functional venous volume is the venous filling time. The venous filling index is functional venous volume divided by the venous filling time; a normal venous filling index is <2 mL/sec. The greater the venous filling index, the more severe the reflux [35,36]. The residual volume fraction, which is the ratio of the residual volume to the function venous volume, is directly proportional to ambulatory venous pressure, which is used to diagnose venous hypertension [37,38].
APG primarily provides an overall assessment of venous function but cannot localize sites of venous reflux. It can be used to monitor overall venous hemodynamics. Changes in APG correlate well with duplex and clinical severity of disease in cross-sectional studies, but there are few studies using APG to predict which patients are most likely to suffer complications (eg, venous ulcer recurrence) [39,40].
Photoplethysmography — Photoplethysmography (PPG) can also be used to assess overall venous hemodynamics. Photoplethysmography is sensitive but nonspecific for the diagnosis of venous insufficiency, and, like air plethysmography, it cannot localize reflux [41]. Although typically performed in a vascular laboratory, handheld PPG devices are available and may be a useful screening tool for chronic venous insufficiency [42].
To perform the test, a light-emitting diode (LED) is placed over the medial ankle region. Transmitted light is reflected back to the PPG diode with the intensity of the reflection indicative of the red cell content of the subcutaneous tissues. After establishing a baseline, the patient is asked to perform 10 tiptoe maneuvers, or to sequentially perform dorsi and plantar flexion of the ankle 10 times. These maneuvers serve to empty the subcutaneous veins, and the PPG recording decreases from the baseline value. As the veins refill passively, the PPG recording rises back to the baseline value.
In the presence of venous reflux, the veins refill more quickly. A venous refill time (VRT) <20 seconds indicates venous reflux. If an abnormal reflux time is normalized with the application of a superficial tourniquet, isolated superficial reflux is present. If the venous refill time does not normalize, either deep venous reflux or a combination of superficial and deep venous reflux is present.
Ankle-brachial index — The ankle-brachial index (ABI) is also often needed to exclude arterial disease in patients with ulceration or symptoms compatible with peripheral artery disease (eg, claudication). Concurrent arterial disease is important to identify because compression therapy, which is the standard treatment for venous ulceration, is contraindicated in the presence of significant arterial occlusive disease [17]. (See "Medical management of lower extremity chronic venous disease" and "Compression therapy for the treatment of chronic venous insufficiency".)
The ABI should be performed in any patient with weak or absent pulses, and in those with symptoms or risk factors for peripheral artery disease (PAD). The ABI is a useful screening tool to diagnose peripheral artery disease, and an ABI ≤0.9 is diagnostic for occlusive arterial disease. An ABI <0.4 represents advanced disease that is often associated with ischemic pain or ulcers. (See "Noninvasive diagnosis of upper and lower extremity arterial disease", section on 'Ankle-brachial index'.)
The ABI is also useful for evaluating patients with ulcers in unusual locations; venous ulcers are most often located medially in the ankle region and are never found above the knee, and only rarely on the foot (table 1). (See "Clinical assessment of chronic wounds", section on 'Differentiation of chronic ulcers'.)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Chronic venous disorders".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and “Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on “patient info” and the keyword(s) of interest.)
●Basics topics (see "Patient education: Varicose veins and other vein disease in the legs (The Basics)")
●Beyond the Basics topics (see "Patient education: Lower extremity chronic venous disease (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●Clinical manifestations (edema, skin changes, venous ulceration) are often sufficient to diagnose venous hypertension or venous obstruction and differentiate venous ulcers from other etiologies (table 1). Objective testing may be needed to confirm the diagnosis, determine the etiology (reflux, or obstruction, or both reflux and obstruction), localize the anatomic site and level of disease, or identify concurrent peripheral artery disease. (See 'Introduction' above and 'Approach to the patient' above.)
●Duplex ultrasonography, combining B-mode real-time imaging and Doppler flow assessment, is the test of choice for the diagnosis of venous obstruction or venous reflux, which is indicative of chronic venous insufficiency. (See 'Approach to the patient' above and 'Duplex ultrasonography' above.)
Duplex ultrasonography should be performed in the following clinical situations:
•If a clinical diagnosis of venous insufficiency or obstruction cannot be established clinically but symptoms are strongly suggestive.
•In patients with signs of chronic venous disease but whose symptoms are questionably related to venous disease, such as mild edema or aching.
•In atypical cases, such as an unusually early age of onset (<40 years) of symptoms, or following trauma.
•In cases of ulceration. Patients with ulceration due to isolated superficial venous reflux may benefit from venous ablation procedures. Significant decreased ulcer recurrence rates have been found with removal or ablation of greater or small saphenous veins.
•In patients with clinically suspected venous disease who do not respond to standard conservative measures.
●Duplex ultrasound establishes the diagnosis of venous obstruction by identifying veins that do not compress normally in B-mode, and which do not demonstrate venous flow on Doppler examination. Duplex ultrasound is also used to identify venous reflux by assessing the duration of reflux in a vein segment; reflux >0.5 seconds is abnormal. (See 'Duplex ultrasonography' above.)
●The role of multidetector computed tomographic (MDCT) venography and magnetic resonance (MR) venography in the management of chronic venous disease is not well defined; however, these may be helpful in identifying treatable pathology and planning surgical interventions in selected patients with chronic venous disease (eg, May-Thurner syndrome). Conventional catheter-based venography (ascending, descending) is rarely needed to make a diagnosis of chronic venous disease but is performed to confirm a diagnosis of venous outflow obstruction prior to intervention. Other physiologic tests of vein function are uncommonly needed. (See 'Venography' above and 'Other tests of vein function' above.)
●Patients with weak or absent pulses, risk factors for peripheral artery disease, or ulcers in locations not consistent with a typical venous ulcer (table 1), should undergo concurrent diagnostic evaluation for peripheral artery disease (PAD) using the ankle-brachial index (ABI). An ABI ≤0.9 is diagnostic for arterial occlusive disease. An ABI <0.4 represents severe disease that is often associated with extremity pain or ulceration. (See 'Ankle-brachial index' above and "Management of chronic limb-threatening ischemia".)
