CEAP classification

An international ad hoc committee of the American Venous Forum developed the CEAP classification for chronic venous disease in 1994 (Table 5.1; see also Chapter 2) with the goal of stratifying clinical levels of venous insufficiency. The four categories and descriptors selected for classification were clinical state (C), etiology (E), anatomy (A), and pathophysiology (P). The CEAP classification has been endorsed worldwide, despite its acknowledged deficiencies. It has been adopted as a standard in many clinics in Europe, Asia, South America, and the United States it is considered the only modern method for reporting data. It’s weakness is the inability to distinguish between levels of smaller superficial veins. The CEAP classification was revised in 2004,³ and is now referred to as ‘advanced’ CEAP.⁴ It includes:

Table 5.1 CEAP classification

Clinical assessment:

The descriptor (a) is added for asymptomatic patients and (s) in case of symptoms.

All clinical features must be reported in the advanced CEAP; for example a patient with telangiectasias, varicose veins, edema, pigmentation, active ulcer and pain is classified C6s in the basic (classical) CEAP but will be C1,2,3,4a,6,s in the advanced (revised) CEAP. This approach carries much more information but stratifies the patients’ samples.

Diagnostic approach

The first step in evaluating a patient with venous disease is to establish his or her clinical class, which rapidly progresses from cosmetic to chronic venous insufficiency. The next is to correlate the symptoms, which place the limb being examined into one of the classes shown in Table 5.1. The patient’s clinical class will dictate the need for further evaluation. In patients with telangiectasias (class 1 or 2), the evaluation can be limited to a physical examination and evaluation of the superficial venous system with a handheld continuous-wave Doppler. Imaging of 83 limbs with clinical evidence of only telangiectatic vessels demonstrated that nearly 25% had insufficiency of the great saphenous vein (GSV) or small saphenous veins (SSV), which was not apparent on physical examination.⁵ Patients with symptomatic class 2 varicosities and class 4, 5, and 6 skin changes require a duplex venous reflux examination because surgical intervention is indicated.^6–10 Recalcitrant cases may require more extensive imaging studies to detect venous occlusive disease. Physiologic testing can be relegated to documentation rather than to diagnosis, and phlebography should be performed only when venous reconstruction is contemplated.

Clinical testing

Historically, tests of venous function have been part of the physical examination of venous insufficiency. These tests have been slowly abandoned due to lack of specificity and sensitivity. As the ‘stethoscope’ of the venous examination, the continuous-wave Doppler examination has replaced most of these tests, while confirmatory duplex testing has supplanted all. With that being said, an educated physician who treats venous insufficiency must have knowledge of these tests and their physiologic background.

Knowledge of the Trendelenburg test (or Brodie-Trendelenburg test) is important for understanding venous physiology and is of historical significance.

Trendelenburg test

For the Trendelenburg test, a tourniquet may be placed around the patient’s proximal thigh while the patient is standing. The patient then assumes the supine position with the affected leg elevated 45 degrees. The tourniquet is removed and the time required for the leg veins to empty, which is indicative of the adequacy of venous drainage, is recorded.

When compared with the contralateral leg, the method just described may demonstrate a degree of venous obstructive disease. Another approach is to elevate the leg while the patient is supine and to observe the height of the heel in relation to the level of the heart that is required for the prominent veins to collapse (Fig. 5.2). Unfortunately, neither procedure is sufficiently sensitive or accurate, or able to differentiate acute from chronic obstruction, which means neither of them is much assistance in current medical practice. This emphasizes the important role of duplex ultrasound in modern evaluation of the superficial venous system. One study found that pneumatic tourniquets only occluded 27% of saphenous trunks.²⁴ Several other physical examination maneuvers, described below, can provide information on the competence of the venous valves.

Figure 5.2 Venous outflow may also be assessed by elevating the leg until the superficial veins collapse and then measuring the distance (X) from the heart to the heel and comparing this measurement with the other leg.

Cough test

One hand is placed gently over the GSV or SFJ and the patient is asked to cough or perform a Valsalva maneuver (Fig. 5.3). Simply palpating an impulse over the vein being examined may be indicative of insufficiency of the valve at the SFJ and below to the level of the palpating hand. This test, however, is not applicable to the examination of the SSV and SPJ (see following section).¹⁴ Palpation of a thrill during this maneuver is generally more diagnostic. One study found a low sensitivity of 0.59 and low specificity of 0.67 with this test.²⁵

Figure 5.3 Cough test. The saphenofemoral junction (SFJ) is palpated while the patient coughs. Palpation of an impulse is indicative of SFJ insufficiency.

Percussion/Schwartz test

One hand is placed over the SFJ or SPJ while the other hand is used to tap very lightly on a distal segment of the GSV or SSV (Fig. 5.4). The production of an impulse in this manner implies insufficiency of the valves in the segment between the two hands. Confirmation of valvular insufficiency can be achieved by tapping proximally while palpating distally. This test can also be used to detect whether an enlarged tributary is in direct connection with the GSV or SSV by palpating over the main trunk and tapping lightly on the dilated tributary, or vice versa. The presence of a direct connection results in a palpable impulse being transmitted from the percussing to the palpating hand. As might be expected, these tests are far from infallible. In a study of 105 limbs, Chan et al²⁶ found that these clinical examination techniques correctly identified SFJ incompetence in only 82% of limbs. False negatives were believed to be caused primarily by previous groin surgery with resultant scarring and by obesity. However, false positives were the result of variations in venous anatomy, such as a dilated tributary emptying into the common femoral vein (CFV) adjacent to the GSV or the absence of valves in an otherwise normal CFV and external iliac vein (seen in 5% to 30% of patients).^27,28 Another study showed a low sensitivity of 0.59 with a high specificity of 0.92.²⁵ A further source of error with the cough and/or percussion test is simply a misinterpretation of the muscle contraction that occurs with coughing as a reflux impulse.

Figure 5.4 Percussion test. The saphenopopliteal junction (SPJ) is palpated while the small saphenous vein is gently percussed. Palpation of an impulse is indicative of SPJ insufficiency.

Brodie-Trendelenburg test

The Brodie-Trendelenburg test traditionally involves the manual obstruction of the proximal end of the GSV (or SSV) while the patient lies supine with the leg elevated, after stroking the vein in a cephalad direction to empty it of blood.^22,29–32 The patient then assumes the standing position, and the leg is observed for 30 seconds (Fig. 5.5). In a ‘nil’ test there is slow filling of the veins from below, and the release of the compression does not result in rapid filling from above, indicating competence of valves in deep and perforating veins and at the SFJ (Fig. 5.6A). Rapid filling of the GSV or more distal tributaries that occurs only after release of the compression constitutes a ‘positive’ test, indicating the presence of an insufficient valve at the SFJ (Fig. 5.6B). In the ‘double-positive’ test, some distension of the veins occurs within the initial 30 seconds while the compression is maintained, as well as additional filling once the compression is released (Fig. 5.6C). This is taken as evidence of incompetent deep and perforating veins as well as reflux through the SFJ. A ‘negative’ test occurs when the veins fill within the initial 30 seconds with no increased filling after the compression is released, implying only deep and perforating valvular insufficiency (Fig. 5.6D). The reverse may not be true; that is, filling in longer than 30 seconds does not imply competence of perforating veins. In a study of 901 extremities, Sherman³³ found that 95% had a nil Trendelenburg test, but surgical exploration later showed incompetent perforators in 90% of these patients. Another study showed a high sensitivity of 0.91 with a low specificity of 0.15.²⁵

Figure 5.5 Brodie-Trendelenburg test. A, The proximal portion of the great saphenous vein is obstructed after the veins have emptied with the leg elevated. B, The distal veins are then observed after the patient stands. C, The veins are further inspected after the tourniquet is released. In this case, filling of the veins on standing and additional filling after tourniquet removal constitutes a double-positive test.

Figure 5.6 Interpreting the Brodie-Trendelenburg test. A, Nil: no distension of the veins for 30 s both while the tourniquet remains on and after it is removed implies a lack of reflux. B, Positive: distension of the veins only after the tourniquet is released implies reflux only through the saphenofemoral junction (SFJ). C, Double positive: distension of the veins while the tourniquet remains on and further distension after it is removed implies reflux through perforating veins and the SFJ. D, Negative: distension of the veins while the tourniquet remains on and no additional distension once it is removed implies reflux only through perforating veins.

The Brodie-Trendelenburg test thus can be an important method of localizing the most proximal site of reflux in most dilated superficial veins by obstructing the GSV, SSV, or whichever vein is suspected of refluxing into a more distal vein. The physician can also place the examining finger over palpable fascial defects in the leg while the patient is supine and then release the obstructions one by one after the patient is standing. This allows the sites of insufficient perforators, or ‘points of control’ (considered so crucial in Fegan’s technique of sclerotherapy), to be defined, because the superficial veins distal to the insufficient perforator fill rapidly once the obstructing fingers are removed (see Chapter 9).^34,35

With this technique, described well in many papers,^21,34–37 the practitioner first marks on the leg the sites of all dilated varicosities. The patient then assumes the supine position with the leg elevated to approximately 60 degrees to empty the veins. After at least 20 seconds, or when the distended veins are flattened, the leg is gently and rapidly palpated to detect any defects in the fascia. With experience, these can be detected easily as places that allow the entrance of the examining finger without the use of any pressure. Fascial defects can be caused by many abnormalities other than perforating veins, thus the practitioner continues the examination by compressing the individual fascial defects with his or her fingers and then having the patient stand. The fingers are then released one by one, starting with the most distal defect, and rapid filling of more distal varicosities is noted (Fig. 5.7). Those defects that cause distal filling when released are assumed to correspond to sites of IPVs. In the presence of a dilated GSV or SSV, these points of reflux first must be controlled with either digital compression or a tourniquet to evaluate the lower volume reflux through the perforators. For the evaluation to be helpful, compression of the defects must first cause sustained flattening of the varicosities when the patient initially stands. If the veins fill before any of the fingers are released, the test must be restarted and other sites compressed until the sites responsible for the reflux are located. This examination is associated with a 50% to 70% accuracy^36–39 compared with findings at surgical exploration. Repeated examination at different times and improvement of edema allows the detection of increased numbers of perforators.

Figure 5.7 A, Compression of fascial defects indicating ‘points of control’ of an incompetent perforating vein with the leg elevated. B, When the patient stands, the varicose vein remains collapsed while pressure is maintained over control points and distends when the control point is released.

Bracey Variation

A clever variation of the Brodie-Trendelenburg technique was proposed by Bracey⁴⁰ in 1958 (Fig. 5.8). He used a flat, 3.8-cm-wide, rubber tourniquet and two rubber rings covered with latex, with inside diameters of 7 cm and 8.2 cm. The smaller ring is used between the ankle and knee and may also be used for the thigh if the patient is thin. If not, the larger ring is used for the thigh. With the patient standing, the small ring is rolled over the foot to just above the ankle, and the rubber tourniquet is then placed below the ring to obstruct any upward flow of blood through the superficial veins. The small ring is then slowly rolled upward, emptying the superficial veins as it moves. As soon as it passes an IPV, the blood enters the superficial vein that connects with it, causing a dilation of the vein. The exit site of the perforating vein may then be marked. This reflux of blood can be accentuated by asking the patient to repetitively dorsiflex the foot. When the ring reaches the knee, the tourniquet is moved up to the knee, just below the ring. Either the smaller or larger ring is then used similarly to examine the thigh.

Figure 5.8 Device for the detection of incompetent perforating vein (IPV). A, Two rubber rings are placed around the ankle, and, B, the more proximally placed ring is slowly rolled upward. C, As it rolls above an IPV, the reflux of blood through the IPV causes an immediate distension of a superficial varix or the formation of a large bulge at the site of the IPV.

Perthes’ test

The Perthes’ test^22,32,41 has several uses, including distinguishing between venous valvular insufficiency in the deep, perforator, and superficial systems and screening for DVT (Table 5.2). To localize the site of valvular disease, the physician places a tourniquet around the proximal thigh with the patient standing. When the patient ambulates, a decrease in the distension of varicose veins suggests a primary process without underlying deep venous disease because the calf muscle pump effectively removes blood from the leg and empties the varicose veins. Secondary varicose veins do not change caliber (if there is patency of the deep venous system) because of the inability to empty blood out of the veins as a result of impairment of the calf muscle pump. In the setting of a concurrent DVT, they may increase in size. If there is significant chronic or acute obstructive disease in the iliofemoral segment, the patient may note pain (venous claudication)^42–44 as a result of the obstruction to outflow through both the deep and superficial systems. Information regarding the presence of deep venous valvular insufficiency and thrombosis is important to note in patient selection. This avoids causing catastrophic complications, such as pulmonary embolism resulting from an undiagnosed and worsened DVT or venous claudication caused by further impairment of venous return. Indeed, these two complications are serious enough to warrant the use of a much more sensitive and accurate method; therefore the Perthes’ test is now of more historical than actual clinical importance.

Table 5.2 Perthes’ test

Finding	Interpretation
Decreased diameter of varicose veins	Primary varicose veins
No change in diameter of varicose veins	Secondary varicose veins
Deep venous patency	Impairment of calf muscle pump
Increased diameter of varicose veins	Deep venous obstruction

To test for perforator valvular defects, the physician may embellish the traditional Perthes’ test by placing a tourniquet around the calf just below the popliteal fossa.³⁴ If the dilated superficial veins in the calf and ankle become less prominent as the patient ambulates, this implies that the blood is being drawn into the deep system through competent perforating veins. However, if the veins become increasingly dilated, the perforating veins must be incompetent. A more involved test, the Mahorner-Ochsner comparative tourniquet test, similarly localizes the site(s) of reflux by observing the leg while the patient walks with the tourniquet placed at various levels on the leg (upper, middle, and lower thigh) (Fig. 5.9).³²

Figure 5.9 Comparative tourniquet test. Distension of the varices in each segment of the leg when the patient ambulates implies the presence of incompetent perforating veins in each segment.

Doppler ultrasound

Although rapidly being replaced by duplex ultrasound, the most practical instrument for evaluating patients with venous disease is Doppler ultrasound. Its first vascular application came in 1960 when Satomura and Kaneko⁴⁶ described a method of studying changes in blood flow in peripheral arteries using an ultrasonic blood rheograph. Its use in the field of venous disease was promoted by many groups, including Sumner et al,⁴⁷ Strandness et al,⁴⁸ Felix and Sigel,⁴⁹, Sigel et al^50–54 and Pourcelot et al.⁵⁵ The instrument is based on the principle of the Doppler effect and consists of an emitting crystal and a receiving crystal. Sound waves are directed into the limb and reflected off the blood cells traveling through the vessel being examined (Fig. 5.10). The input picked up by the receiving crystal may be connected to a variety of audio or graphic recording systems. Dopplers come with either continuous or pulsed-wave ultrasound beams; the continuous-wave Doppler is adequate for venous examination, even though the signal represents a composite of the flow in all vessels in the path of the ultrasound beam. Thus, selective examination of one particular vessel may not always be possible. Pulsed Dopplers are used in sonar systems and in medical ultrasound imaging and are required when the intent is to focus the beam at a particular depth. Dopplers are also available in either directional or nondirectional forms. The directional type is capable of determining the direction of blood flow and depicts the direction on the tracing as either a positive (toward the probe) or negative (away from the probe) deflection (Fig. 5.11). Although the directionality greatly simplifies the interpretation of the tracing, experience with a nondirectional Doppler allows the examiner to make this determination easily, based on certain augmentation maneuvers.

Figure 5.10 Doppler ultrasound. Sound waves are emitted from the transmitting crystal, reflected by moving particles (blood cells) within the vessel being examined, and picked up by the sensing crystal.

Figure 5.11 Bidirectional Doppler tracing. A, Positive deflection indicates flow toward the probe; B, negative deflection indicates flow away from the probe.

The transmission frequency of the ultrasound beam may range from 2 to 10 MHz; the depth of penetration varies inversely with the frequency. Therefore, a frequency of 4 MHz produces a broad beam with deep penetration, which is especially useful for examining the deep veins in the pelvis and abdomen. A frequency of 8 MHz is much better suited for the examination of more superficial veins, including superficial segments of the deep veins of the legs, since it produces a narrower beam with relatively less penetration. Dopplers used for evaluation of the venous system generally permit detection of flow rates as low as 6 cm/second.⁵¹

Characteristics of Doppler waveform

Venous Doppler signals display five characteristics (Box 5.2). In a normal patient, there should be a spontaneous signal over any vessel not otherwise vasoconstricted, and the flow should be only unidirectional. This signal diminishes in intensity with inspiration as descent of the diaphragm causes a rise in intra-abdominal pressure, thus decreasing venous outflow from the leg. It will be augmented similarly with exhalation. This waxing and waning of the intensity of the signal with the respiratory cycle is a phenomenon known as phasicity. Venous signals are continuous except for their respiratory variation and are not pulsatile, except in the setting of elevated right heart pressure such as congestive heart failure or tricuspid insufficiency⁵⁶ or in the normal CFV.⁵⁷ Finally, and most important to their usefulness in the evaluation of patients with varicose veins, venous signals may be augmented with certain compression maneuvers. It is the response to these maneuvers that provides information regarding the sites of valvular insufficiency and obstruction of the venous system.

Box 5.2 Venous Doppler characteristics

• Spontaneous

• Unidirectional

• Phasic with respiratory cycle

• Nonpulsatile

• Augmented

By compressing the limb distal to the Doppler probe (Fig. 5.12), the examiner increases the flow through the vein; an immediate increase in the signal intensity should be heard if there is no proximal obstruction. In the presence of a hemodynamically significant DVT, the augmented response is weaker and delayed compared with the contralateral side. With the patient in the upright position, release of distal compression should be followed by silence as the valves close in response to the downward pressure of the blood being pulled by gravity. With the patient in the supine position, release of the compression should normally be followed by the return of the lower intensity spontaneous signal or by silence in the smaller veins. In the setting of valvular insufficiency at the level of the Doppler probe, a loud reflux flow signal can be heard on release of distal compression as blood is pulled in a caudal direction by gravity. To quantitate this reflux flow, the compression used may be standardized by using a pneumatic cuff inflated to a standard pressure (e.g. 80–120 mmHg), and the amplitude and duration of reflux may be read from the tracing obtained. To be considered true reflux and not merely delayed valve closure, the duration of reflux must be at least 0.5 seconds.^8,58 Although many now believe that over 1 second is the appropriate duration above which to consider it abnormal.

Figure 5.12 A, Method of producing augmentation of flow in the posterior tibial vein by distal (foot) compression. B, Shows: A, normal flow; B, venous obstruction; C, valvular insufficiency.

The other method of augmentation is proximal compression and release (Fig. 5.13). Proximal compression produces a transient obstruction to outflow and thus causes an accumulation of blood distally, with an associated interruption of the Doppler signal. On its release, the large bolus of blood flowing past the Doppler probe creates a loud signal. This has also been found to be the more sensitive maneuver in diagnosing DVT, even that limited to calf veins, with a diminished or delayed signal indicative of a significant thrombosis.^59,60 Valvular insufficiency is discovered easily, because proximal compression yields a loud reflux flow instead of silence.

Figure 5.13 A, Method of producing augmentation of flow in the posterior tibial vein by release of proximal (calf) compression. B, Shows: A, normal flow; B, venous obstruction; C, valvular insufficiency.

In early descriptions of the use of Doppler ultrasound for detection of venous disease, Sigel et al⁵¹ named the various sounds ‘S’ for spontaneous and ‘A’ for augmented. They further specified ‘A’ sounds as distal (if the compression was distal to the probe) or proximal (if the compression was proximal to the probe), and positive if the ‘A’ sound was heard directly with compression or negative if heard on release of the compression. This notation thus makes it possible for four ‘A’ sounds to be generated at each site being examined. Table 5.3 summarizes these sounds and their significance. This schema provides a useful method of categorizing these sounds; however, the ‘S’ and ‘A’ nomenclature has not found generalized acceptance. Instead, sounds are referred to as manifesting flux or reflux, antegrade or retrograde flow, patency or incompetence, etc.

Table 5.3 Interpretation of ‘A’ sounds

Type of ‘A’ Sound	Condition If Present	Condition If Absent
Distal positive	Normal	Venous obstruction
Distal negative	Valvular insufficiency	Normal
Proximal positive	Valvular insufficiency	Normal
Proximal negative	Normal	Venous obstruction or marked valvular insufficiency

Augmentation of the most proximal portion of the GSV and of the more proximal deep veins is accomplished either by compressing the abdomen or by using a variation of the proximal compression and release, and the Valsalva maneuver (Fig. 5.14). The rise in intra-abdominal pressure caused by descent of the diaphragm is accentuated by contraction of the intercostal muscles. In the normal patient, an abrupt closure of the valves results in silence. However, more than 38% of normal persons have a brief period of reflux at the commencement of the Valsalva.⁶¹ Also, with a weak effort by the patient, a slow retrograde flow may pass through the valve and produce a Doppler flow signal because sufficient force to cause valve closure has not been generated. Visualization of the valves using ultrasound demonstrates that these valves do close eventually, and that they are not actually insufficient.⁶² Therefore, the continuation of reflux through at least half of the period of compression, or at least 0.5 seconds (usually 1–4 seconds), is important in diagnosing pathologic valvular incompetence.^8,58 A less sensitive, but perhaps more specific, response may be elicited simply with deep breathing. With valvular insufficiency, instead of hearing the cessation of flow as the patient takes a deep breath, flow is reversed and a continuous signal heard, which shows a reverse deflection on a directional Doppler tracing (Fig. 5.15). The Valsalva maneuver is sometimes hard to explain to patients, and difficult to standardize; to facilitate, several tricks have been proposed, for example blowing into a surgical latex glove.⁶³ When using the Valsalva maneuver to produce reflux while listening over more distal veins, the examiner must realize that the path of the reflux may be either straight down the superficial vein or through the deep vein to the perforating vein and into the superficial vein (Fig. 5.16).⁶⁴ Therefore, additional testing is necessary to further delineate the exact site of abnormality. This is easily accomplished by manually obstructing the superficial vein; if reflux is still heard, the retrograde flow is assumed to be traveling through the deep and perforating systems.

Figure 5.14 Augmentation of flow in the common femoral vein or through the saphenofemoral junction with intermittent compression of the abdomen or with Valsalva maneuver and release (not shown).

Figure 5.15 Venous Doppler tracings. A, Normal phasic flow. B, Reflux with deep inspiration in the setting of valvular insufficiency.

Figure 5.16 Pathways of reflux are typically through the saphenofemoral junction but may also be through atypical channels, such as through a deep vein via a perforating vein into a superficial vein (shown). Reflux may also travel through a superficial vein via a perforating vein into another superficial vein (not shown).

(Redrawn from Schultz-Ehrenburg U, Hubner HJ: Reflux diagnosis with Doppler ultrasound. In: Findings in angiology and phlebology, vol 35, New York, 1989, FK Schattauer Verlag.)

Doppler examination technique

The Doppler examination of the patient is begun with the deep veins, several of which are easily accessible.

Femoral Vein

With the patient supine and the hips slightly flexed and externally rotated, the physician first locates the pulsatile signal of the femoral artery in the groin. If desired, the examination can also be performed with the patient standing, which may provide a more physiologic evaluation because most symptoms occur when the patient is upright and reflux is more easily elicited. The Doppler probe is then gradually angled medially until the spontaneous, continuous sound of the femoral vein, suggestive of a windstorm, is heard. Clear phasicity with respiration should be detected easily. Patency can be further tested by manually compressing the thigh or calf and listening for a strongly augmented signal. Valvular competence may be assessed by listening first for the phasic waxing and waning of the signal that, in severe cases of insufficiency, shows a decrease in intensity of the signal followed by a reversal of flow direction as inspiration progresses, rather than the expected silence. The patient is then asked to perform a Valsalva maneuver; alternatively, the physician can press on the abdomen. These latter maneuvers should cause an abrupt closure of the valve and silence, followed by a more intense antegrade flow on release if the valves are competent. A loud reflux flow heard through the Valsalva maneuver is pathognomonic of valvular insufficiency, which may be present in 5% to 30% of normal patients and, in one study, was found in 100% of patients with bilateral GSV varicosities.⁶⁵ The effort invested in the Valsalva maneuver may be standardized to ensure the proper force and reproducibility by asking the patient to blow into a tube connected to a mercury manometer until the mercury column rises to 30 mm.

Differentiation of femoral from saphenous veins

Because the SFJ is located close to the femoral artery pulsation, valvular incompetence at the junction can sometimes be mistaken for CFV insufficiency. Several techniques can be used to aid in making this important differentiation. The saphenous vein is much easier to compress than the femoral vein, so manual compression using the Doppler probe may occlude the saphenous vein and allow the physician to listen selectively to the femoral vein. A separate occlusive device, such as the physician’s other hand or a tourniquet, may be used to compress the GSV distal to the Doppler probe and thus prevent reflux through it. Any reflux still heard is assumed to be through the femoral vein. Finally, moving or angling the Doppler probe in a cephalad direction may enable the physician to direct the ultrasound beam away from the saphenous vein to a more proximal segment of the femoral vein. Still, there are a small number of patients in whom differentiation of femoral from junctional signals may be impossible to determine by use of only the continuous-wave Doppler; an imaging procedure such as duplex scanning, which uses a pulsed ultrasound beam, may be necessary in such cases.^66,67

To achieve uniform testing of venous reflux between institutions, comparable methods of testing by duplex and Doppler ultrasound scanning are desirable. In one study, the Valsalva maneuver was compared with rapid cuff deflation performed in the 15-degree reverse Trendelenburg position and in patients’ standing. Duplex technology allowed estimation of duration of retrograde flow and peak velocity. The general conclusions of the study was that the Valsalva method is best performed in the reverse Trendelenburg position as opposed to standing, but the cuff technique is more effective in the standing position.⁶⁸

Popliteal Vein

For the next site of examination, the popliteal vein, the patient may be in the supine, prone, or standing position. The most physiologic position is standing, and it is advisable to perform all presclerotherapy Doppler examinations in this position. It is important to have the knee slightly flexed, however, since full extension of the knee joint may cause a functional obstruction of the popliteal vein. Also, if the examination is performed while the patient is standing, the weight should be borne on the opposite foot (Fig. 5.17). The pulsatile arterial signal is located, generally, in the popliteal crease just lateral to the midline; the Doppler probe may be angled medially to find a softer, although spontaneous, venous signal, or it may be left over the popliteal artery. Augmentation with either calf compression or thigh compression and release, as described previously, discloses both obstruction and valvular insufficiency. The Valsalva maneuver discloses reflux only if the more proximal deep veins (CFV) are also incompetent. As with reflux heard at the femoral level, reflux at the popliteal level may actually be caused by reflux through the SPJ. Therefore, in any patient who appears to have reflux through the popliteal vein, the test should be repeated while firm manual compression is applied to the SSV. Obliteration of the reflux in this manner localizes the site of reflux to the SPJ and not to the popliteal vein itself. Another method consists of slightly compressing an uninvolved portion of the calf with one finger, which causes flow through the popliteal vein and not the SSV.⁶⁴ Popliteal vein reflux can be detected in this way with a sensitivity of 100% and a specificity of 92%, with most false positives being the result of variations in the anatomy of the SSV (see Chapter 1).^8,15,69 The presence of popliteal valvular insufficiency is an important finding because it is associated with diminished calf muscle pump function and may be the most important prognostic factor in the development of venous ulceration.^8,70,71 This relationship is not absolute, however; one study showed that popliteal incompetence was found in only 20% of patients with ulceration and 31.2% of postphlebitic legs.⁶¹

Figure 5.17 The popliteal vein is examined with the knee flexed and the weight borne on the opposite foot.

Although the continuous-wave Doppler is adequate for testing GSV incompetence, all reflux detected in the popliteal fossa should be checked by duplex examination. The continuous-wave Doppler examination has a sensitivity of 95% and a specificity of 100% for SFJ examinations, and a sensitivity of 90% and a specificity of 93% at the SPJ.⁷²

Posterior Tibial Vein

The final deep vein that should be examined is the posterior tibial vein, located just posterior to the medial malleolus and beside the posterior tibial artery, which has an easily locatable pulsatile signal. This vein is frequently vasoconstricted, except if the patient is examined in a warm room, in which a spontaneous signal may be noticeable. Augmentation maneuvers are the same as described for the other deep veins. Again, although the Doppler is generally not felt to be sufficiently sensitive in the diagnosis of DVT below the knee, the response of posterior tibial venous flow to the release of calf compression has been found to allow an 87% accuracy in this diagnosis.^59,60

Scanning veins below the knees by ultrasound presents unique difficulties because of the small size of the veins and their deep position. The addition of color to the Doppler examination has improved this situation immeasurably, and the rates for detection of the posterior tibial, anterior tibial, and peroneal veins has been raised to 98%, 96%, and 96%, respectively.⁷³

Superficial Veins

After the deep veins mentioned previously have been examined, attention is turned to the superficial and perforating systems. The major saphenous trunks and their junctions with the deep veins should be examined with the patient in the standing position. Because of the lower flow rate in these vessels, a spontaneous signal may only rarely be audible. The presence of a saphena varix, or a visible bulge over the SFJ, is nearly pathognomonic of valvular incompetence. The junction is easily located with the Doppler approximately two fingerbreadths in the femoral triangle below the inguinal ligament. Alternatively, the physician may first locate the SSV in the thigh and then gradually move the Doppler probe superiorly and laterally while repetitively compressing the GSV until its location is reached. A positive cough or percussion test may also help to localize the site of the SFJ. The presence of reflux on release of more distal compression is indicative of SFJ insufficiency. Again, the magnitude of the compression can be standardized for serial comparisons by using a pneumatic cuff inflated to a specific level. Also, the Valsalva maneuver may be used to elicit reflux, although manual compression of the SFJ by the inguinal ligament may occur during a forceful Valsalva, and more proximal competent valves may impede the retrograde flow,⁷⁴ thus creating the false impression of a competent valve.

If no reflux is heard over the SFJ, the physician should not assume that the entire GSV is competent.^75–77 The perforator(s) in Hunter’s canal may frequently be the first abnormality to develop, leading to dilation and incompetence beginning just below the level of the middle thigh (see Chapters 1 and 3).^33,78 Reflux frequently originates in branches of the GSV⁷⁹; the ‘atypical refluxes’ described by Schultz-Ehrenburg and Hubner⁶⁴ may be the most common. Incompetence of the GSV that is limited to the calf suggests insufficiency of the geniculate or lower leg perforators. Therefore, it is important to test the GSV for reflux in the groin, at the level of the knee, and in the lower leg and not to assume that it is normal until all sites fail to demonstrate reflux. In addition, there is a growing consensus that dilation may occur because of biochemical abnormalities in the muscle of the varicose vein wall. Thus, valvular insufficiency may not necessarily be a descending process, as was once assumed. This underscores the need to evaluate the entire length of the GSV in determining which portions of the vein to treat.⁷⁵

Examination of the SSV and SPJ is best carried out with the patient standing and the knee slightly flexed, as previously described. The SSV is felt more easily with the knee flexed and the popliteal fossa relaxed.¹⁴ When enlarged, the SSV generally is still not visible, but it is easily palpable as a spongy tubular structure leading inferiorly from the popliteal crease. By listening over the popliteal vein and tapping the leg very gently 5 to 10 cm below the probe, the examiner selectively compresses and thus listens to the SSV and not the popliteal vein, which requires a much stronger force. Since the termination of the SSV is variable, the exact location of the probe cannot be known for certain; therefore it is difficult to determine if any reflux heard is originating from the SPJ or is simply within a dilated SSV. The Valsalva maneuver or compression of the thigh aids in this differentiation because it results in reflux only if the SPJ is incompetent. Distinction between flow through the SPJ and popliteal vein can also be difficult but is facilitated by manually compressing the SSV below the probe while pressing on the calf, as described previously. Abolition of the reflux is evidence that the source is the SPJ.¹⁵ Another method is to listen over a more distal segment of the SSV, along the posterolateral calf, and to compress and release the SSV at the popliteal crease. Reflux or only augmentation after release is detected easily.

Perforating Veins

The examination of perforating veins is, at best, only 80% accurate using the Doppler.^80–82 Many believe that physical examination – that is, palpation of fascial defects in which the incompetent perforator meets a dilated superficial vein at the depth of the superficial fascia – is perhaps even more helpful.⁸³ In fact, published studies document that palpation is accurate only 51%³⁷ to 69%³⁹ of the time (Fig. 5.18). This technique, which is discussed more fully in Chapter 9, yields a large number of false-positive results because a fascial defect may result merely from dilation of a superficial varicosity or even from a separate pathologic process, such as a muscle hernia. In these situations, the Doppler affords increased reliability. In fact, Doppler examination for IPVs is advised after preliminary clinical localization of suspected sites (by listening for the characteristic to-and-fro movement of blood over sites of palpable defects in the fascia). Some authors have advocated the placement of tourniquets at 10 cm (4 inch) increments along the course of the lower leg before listening for flux and reflux at the sites of fascial weakness while the calf or thigh is repetitively compressed.^80–82 A simpler approach is to place one tourniquet just below the level of the fascial defect and another just above it. While listening with the Doppler over each marked fascial defect, the physician compresses the foot (Fig. 5.19). Any audible signal thus represents flow proximally through the deep system and outward through an IPV. This provides greater specificity because it interrupts the flow through the superficial veins, thus allowing selective examination of the perforating veins. Figure 5.20 provides a rational method of recording the venous Doppler examination findings.

Figure 5.18 Palpation is often deceptive and clinical localization (P) of perforating veins is inaccurate. Duplex evaluation brings back the correct localization (X).

Figure 5.19 After making fascial defects palpable with the leg elevated, the Doppler is used to detect outward flow at each site. Tourniquets are placed just proximal and distal to each potential incompetent perforating vein, and the foot is compressed to produce flow upward through the deep veins.

Figure 5.20 Chart for recording venous Doppler examination. GSV, great saphenous vein; SFJ, saphenofemoral junction; SPJ, saphenopopliteal junction; SSV, short saphenous vein.

Duplex ultrasound scanning

Duplex scanners are ultrasound machines that generally use a 7.5–12 MHz imaging probe along with a 3–5 MHz pulsed Doppler to enable visualization of the superficial venous system and to determine the direction of blood flow within the examined veins. Anatomy, flow within the veins, and the movement of the valves may also be studied (Fig. 5.21). Current scanners (sometimes termed triplex if displaying real-time color imaging and pulsed Doppler at the same time) use a computer-generated color system in which antegrade and retrograde flow may be coded to appear as different colors (red or blue) with varying intensities (brighter with lower velocities, paler with higher velocities), thus allowing immediate integration of this information by the examiner (Figs 5.22–5.24). Many new features have been introduced to enhance picture detail and contrast (B flow, Power Doppler, etc.), which can be helpful in specific cases. Visual ultrasound images have one of their greatest uses within the field of venous disease in the diagnosis of DVT and now have all but replaced venography in centers where the instrumentation is available (Fig. 5.25).^88–93 Since the 1990s, alterations in the frequency range of the probes (higher frequencies: 10–20 MHz) have enabled clear resolution of superficial and deep veins, thus introducing an entirely new era in the diagnosis of varicose veins and their treatment by sclerotherapy.

Figure 5.21 Duplex scanners may provide clear images of anatomic structures such as the saphenofemoral junction and venous valves (arrow).

Figure 5.22 Color scanners display flow: in the normal direction in blue (A), and reflux flow in red (B).

Figure 5.23 Color Doppler image of the confluence of the epigastric and great saphenous vein (GSV) showing reflux into the GSV.

(Taken with Terason 2000 system.)

Figure 5.24 Color Doppler image of a perforator in the calf.

(Taken with Terason 2000 system.)

Figure 5.25 Ultrasound provides clear images of deep venous thrombosis (arrow). Thrombus may appear as an echogenic mass or simply result in the vein being noncompressible.

While studies have demonstrated that the examination is best performed with the patient standing,⁹⁴ it is often difficult to perform this practically. Most examinations are not performed on a tilt table with patients at least 30 degrees in reverse Trendelenburg position. The cut-off value for reflux in the veins is greater than 500 ms, except for the femoropopliteal vein, where it is 1 second (Fig. 5.26).

Figure 5.26 Duplex image showing reflux by pulsed-wave Doppler, lasting more than 3 seconds.

(Taken with Terason 2000 system.)

Aid to sclerotherapy

If the Doppler used to act as the ‘ears’ of the phlebologist, the duplex scanner must be considered both the ears and eyes as it allows the examiner to ‘see’ much more than is ascertainable otherwise. The duplex scanner allows for determination of the exact anatomy, including the important SFJs and SPJs. The anatomy of the SFJ is generally believed to be similar in all persons; however, there is actually significant variation. Although not generally accepted as fact, duplication of the GSV has been reported to be found in up to 27% of persons^11–13 and is easily demonstrable with this technology (Fig. 5.27). Because the termination of the SSV is so variable, the exact location of the SPJ or the termination of the SSV in the GSV or its tributaries (the superficial or common femoral veins) or in tributaries of the internal iliac veins⁹³ can be seen on the duplex scan (Fig. 5.28). In the past, selective venography was advised to determine the exact site of termination of the SSV before the SSV was operated on.^95–97 Duplex ultrasound provides this piece of information noninvasively.^98,99 Injections into the SFJ or SPJ, if performed under ultrasonic guidance,^100,101 confer an added degree of accuracy and potentially safety to this procedure (Fig. 5.29). Injections into IPVs, particularly in areas of ulceration or lipodermatosclerosis, can be facilitated greatly by performing them under ultrasonic guidance.¹⁰² These areas may be particularly difficult to examine clinically or with a Doppler alone, and injections administered blindly into these areas can be quite risky because of the proximity of the posterior tibial vein and artery. Finally, the anatomic basis for proximal recurrences following GSV or SSV ligation may be found through duplex scanning. Because recurrent varicose veins occur in 20% to 80% of patients who have had varicose vein surgery, duplex scanning has allowed classification of the recurrences so that future studies can be conducted in a rational and well-planned fashion.¹⁰³

Figure 5.27 Anomalies such as this duplication of the great saphenous vein (arrow) may be visualized with a duplex scanner.

Figure 5.28 The termination of the small saphenous vein (SSV) can usually be visualized quite easily with duplex scanning. After release of the calf compression, showing reflux. POP, popliteal vein.

Figure 5.29 Injection into the saphenofemoral junction (SFJ) may be performed under ultrasonic guidance. The needle is seen inside of the SFJ (arrow).

(Courtesy Robert M. Knight, MD)

In addition, as McMullin and Appleberg¹⁰⁴ have found, duplex measurement of antegrade flow rates through the CFV, superficial femoral vein, popliteal vein, and GSV may be used to determine the degree of resistance within the deep veins and thus the preferential flow up the superficial veins in patients with chronic venous insufficiency. If it is found that the flow rate upward through an incompetent GSV is quite high in a given patient with disease in more than one segment of his or her venous system, removal or closure of this vein might be contraindicated. The amount of flow generated by active dorsiflexion of the foot may also provide information on the efficacy of the musculovenous pump.

Duplex scanning has allowed definition of the saphenous vein and its relationship to the superficial fascia and the deep or muscular fascia (Fig. 5.30). Throughout its length, duplex scanning has shown the GSV to lie on the muscular fascia. It is covered in its full length by the superficial fascia or membranous fascia, a connective tissue lamina that descends from the inguinal ligament to the ankle. This lamina is formed by the interlacing of connective tissue sheets. After the superficial fascia arches over the GSV, it fuses with the muscular fascia to create a saphenous compartment. In duplex scanning, this compartment has been called the ‘Egyptian eye’.¹⁰⁵ This identification is crucial for correct duplex scanning and separating varicose tributaries of the saphenous vein from the saphenous vein itself.

Figure 5.30 Duplex scanning defines the saphenous vein and its relationship to the superficial fascia and the deep or muscular fascia. The superficial fascia, after arching over the great saphenous vein, fuses with the muscular fascia to create a saphenous compartment. This compartment has been called the ‘Egyptian eye’ in duplex scanning, as shown in this scan.

Post-treatment evaluation

Another major use of duplex ultrasound with sclerotherapy is for follow-up of treatment. As mentioned previously, the Doppler does not allow differentiation between thrombus and fibrosis, both of which yield abolition of flow through the involved vein segment. The duplex scanner can differentiate these two situations very clearly. Depending on its age, thrombus may appear as a variably echogenic space associated with soft tissue swelling and inflammation, whereas fibrosis appears more often as a dense line with no associated inflammatory reaction (Fig. 5.31). Because patient response to treatment is so variable, physicians now can more accurately determine if the treatment rendered has been completely effective, thus producing fibrosis, or if the vessel is occluded by thrombus, thereby necessitating additional treatment. Many apparent treatment failures with early recurrence are likely to be found to be the result of inadequate treatment and not inadequate response.

Figure 5.31 Ultrasound can be used to differentiate thrombosis (A) from sclerosis (B). (Horizontal white line indicates the diameter of the vessel.)

(Courtesy P. Raymond-Martimbeau, MD)

Another important advantage of duplex ultrasound over the Doppler is its ability to quantitate venous reflux. This parameter has been found to have some prognostic potential. The flow in milliliters per second at peak reflux was measured in 47 limbs of patients who had chronic venous problems. It was found that dermatitis or ulceration did not develop if the sum of the peak refluxes in the GSV, SSV, and popliteal vein was less than 10 mL/second. A sum of greater than 15 mL/second was associated with a high incidence of these sequelae.^8,106 In addition, superficial venous reflux alone may cause ulceration if the peak flow is greater than 7 mL/second.¹⁰⁷

In summary, advantages provided by duplex scanning include evaluating the anatomy of the main saphenous trunks and recurrences, injecting difficult areas under ultrasonic guidance, determining the presence of fibrosis, and quantifying both reflux and forward flow. Unfortunately, both the Doppler and duplex scanners are usually used to obtain only anatomic information, thus leaving the actual hemodynamic effect of the various abnormalities unknown. Functional studies may therefore be necessary in certain situations.

Photoplethysmography

The most widely used functional evaluation for presclerotherapy purposes is photoplethysmography (PPG).^108–111 Various forms of plethysmography have been used to evaluate venous function since 1956,¹¹² and they have been shown to correlate well with venographic findings¹¹³ and ambulatory venous pressure (AVP) measurements. In one study of 338 paired measurements of PPG and AVP, the correlation co-efficient was 0.9.¹⁰⁸ The principle of PPG is quite simple, and the test is easy and quick to perform. An infrared light source and sensor are attached with adhesive to the medial aspect of the lower leg, approximately 10 cm proximal to the medial malleolus. The infrared light is transmitted into the leg to a depth of approximately 0.5 to 1.5 mm, within the subdermal venous plexus, where it is absorbed by hemoglobin in red blood cells. Of the light that is not absorbed, a certain amount returns to the sensor. Therefore, the amount of infrared light reflected is inversely proportional to the volume of blood in the skin. Once a baseline level is reached, the patient is asked to actively dorsiflex the foot 5 to 10 times, which activates the calf muscle pump and produces venous outflow (Fig. 5.32). With a reduced volume of blood in the calf and the subdermal plexus, more light is reflected and the tracing shows a gradual deflection (the direction of the deflection depends on the electronics of the particular instrument). At the conclusion of exercise, the patient is asked to relax and the tracing then either returns to the original baseline value or levels off at a new value of light transmission. The time required for this value to be reached, the venous refilling time (VRT), provides information on the presence and degree of reflux of blood through either superficial or deep veins (Fig. 5.33).

Figure 5.32 A, Photoplethysmography measures venous emptying during, and refilling after, exercise of the calf and foot muscles. B, Emptying is accomplished with 5 to 10 dorsiflexions of the foot.

Figure 5.33 Photoplethysmography. Light reflection is enhanced as the calf muscle is exercised and blood is pumped out of the leg. A reduction in light reflection is seen once the leg is allowed to rest. The venous refilling time (VRT) indicates the degree of reflux, although it is not quantitative.

Normally, refilling of blood occurs only through the arterial circuit and takes at least 20 to 25 seconds. A value less than 20 seconds indicates the presence of an abnormal refilling channel, namely retrograde flow through incompetent superficial or deep veins. Repeating the test while firmly compressing a particular vein allows the physician to assess the degree of hemodynamic disturbance contributed by that vein. Specifically, if the VRT lengthens from 15 to 35 seconds when a vein is compressed, the examiner can be assured that this vein is contributing significantly to the patient’s problem. Similarly, in the setting of both superficial and deep venous incompetence, by compressing the superficial veins the examiner theoretically can prevent reflux of blood through these veins and observe the effect of the deep venous system alone. If the VRT lengthens significantly when a tourniquet is placed around the thigh to occlude the superficial veins, this implies the dominance of the superficial system in the patient’s pathology. If the VRT remains essentially unchanged, the examiner can assume that the deep veins are the primary problem. A word of caution must be mentioned, however, relating to the method of compression of the vein(s). A simple tourniquet, such as that used in phlebotomy, is used frequently and has the advantage of compressing all of the superficial veins, even those that are not suspected of being enlarged and insufficient. However, it is important to be aware that this type of compression may not adequately compress all of the superficial veins, particularly large, thick-walled varicosities.

The need for the awareness just mentioned is especially important in obese patients, but it is also necessary in patients of normal weight. By using a duplex scanner to visualize the flow through the GSV, McMullin et al¹¹⁴ found that the pressure within a 2.5-cm-wide tourniquet required to prevent reflux through the vein varied between 40 and 300 mmHg in the 40 patients studied. Therefore, manual compression applied directly to the vein being considered is the preferred method because it allows more reliable interruption of the flow and gives reproducibly accurate results.

VRT has been found to correlate well with AVP measurements, which have long been considered the gold standard in the functional evaluation of venous hemodynamics. VRT may vary between 20 and 65 seconds when AVP is below 40 mmHg, but a VRT of less than 15 seconds is found only if the AVP is higher than 40 mmHg.¹¹⁵ AVP measurements show a linear relationship between their value and the incidence of venous ulceration.^8,116

Photoplethysmography may be used to quantify the blood changes within the subdermal plexus, thus quantifying the degree of reflux. This involves performing an in vivo calibration maneuver that allows the examiner to assign a numeric value to the deflections on the tracing.^117,118 The transducer is placed on the leg in its usual location while the patient rests in the supine position, and the tracing on the recorder is set to a zero baseline. The patient then stands, bearing weight on the opposite leg, and after the tracing levels off, the gain is adjusted so that the deflection reflects the calculated hydrostatic pressure in the superficial veins, measured by the distance from the right atrium to the site of the transducer on the leg. This maneuver is repeated until the zero baseline and standing levels of subdermal plexus blood content reproducibly reflect the hydrostatic pressures. The decrement in the tracing is then proportional to the degree of fall in AVP, as measured by invasive venous pressure recordings.

Plethysmography has been vigorously defended and advocated by some.¹¹⁹ However, others have questioned the use of this tool because of its lack of correlation with duplex scanning.¹²⁰ The authors of this study stated, ‘These results do not warrant the continued use of photoplethysmography for surgical decision-making in patients with suspected venous insufficiency.’

Recent studies have demonstrated the efficacy of PPG in evaluating venous hemodynamics.^121,122 A PPG system can be calibrated to quantify the blood volume displacement with leg elevation and/or exercise. In a study of patients with isolated superficial venous disease, digital PPG was found to give reproducable results.¹²³ A determination of venomuscular pump efficiency has been demonstrated to quickly gauge the severity of venous disease. The use of PPG may also allow the practitioner to assess the effectiveness of superficial vein treatment.

Light reflection rheography

Light reflection rheography (LRR), which is basically a form of PPG, was intended to improve on the original PPG system.^124,125 On account of its incorporating three light sources, the infrared light beam can be focused at a standardized depth of penetration (0.3–2.3 mm) to cover the subcutaneous venous plexus. Dermal pigment, such as that commonly found in patients with chronic venous insufficiency, is concentrated in the more superficial layers of the skin and interferes with light transmission, yielding inaccurate and variable values. It was hoped that by focusing its light beam on the deeper tissues, the LRR would not be as affected by the tissues containing the majority of the pigment. This did not prove to be the case, however, and it was felt that calibration of the system might neutralize the effect of variables such as skin thickness, skin pigment, and local blood volume on light absorption. This improvement is now available as digital PPG (D-PPG) or calibratable PPG (C-PPG).¹¹⁵

The D-PPG contains a computer that permits changes in light intensity from the infrared light source according to the optical properties of the skin. The machine emits a standard light intensity and awaits reflection of the unabsorbed light. If it is below a certain level, the intensity of the emitted light is automatically increased until the intensity of reflected light reaches a level at which the machine can function accurately. This was demonstrated nicely by Kerner et al,^126,127 who recorded essentially the same response to dorsiflexion even after the leg was covered with a dark paint.

The C-PPG is essentially the same as the D-PPG, except that the changes in light intensity are adjusted manually. This device was tested on normal subjects and on patients with venous disease. By comparing the time with 90% refilling, or by combining the results obtained during postural changes and dorsiflexion in order to obtain exercise drainage volume, it was possible to significantly differentiate patients with venous ulcers from those with varicose veins and from the normal controls.¹¹⁵ Other parameters that can be calculated include venous filling volume and pump efficiency.

The usefulness of PPG in the assessment of venous valvular insufficiency is undisputed; however, claims that it is accurate in diagnosing DVT are controversial. The general statement that a ‘picket fence’ pattern (Fig. 5.34) produced by the 10 dorsiflexions with essentially no vertical movement off of the baseline is diagnostic of DVT is certainly incorrect, because there are many false-positives using this criterion. In a study of 30 limbs, the correlation coefficient between venous emptying and AVP was only 0.73.¹²⁴ However, in a study performed at the University of Miami,¹²⁸ the slope of the deflection correlated well with the presence of acute DVT as documented by venography. As shown in Figure 5.35, the finding of a slope (R/T) of less than 0.31 mm/s predicts the presence of DVT with a 96% sensitivity. Still, LRR alone currently is not considered sufficient to make the diagnosis of DVT, and at least one other noninvasive test is required to confirm the diagnosis.

Figure 5.34 A ‘picket fence’ pattern may indicate deep venous thrombosis but may also be seen with chronic venous insufficiency without thrombosis.

Figure 5.35 Usefulness of photoplethysmography in the diagnosis of deep venous thrombosis (DVT) may be improved by examination of the slope R/T; less than 0.31 mm/s predicts the presence of DVT with a 96% sensitivity. R, refilling; T, time; VRT, venous refilling time.

Air plethysmography

Air plethysmography (APG) is one technology that is just as simple to use and potentially supplies a great deal of additional information compared with the conventional PPG.¹²⁹ This device consists of a 14-inch-long, tubular, polyvinyl-chloride air chamber that surrounds the leg from knee to ankle. This is inflated to 6 mmHg and connected to a pressure transducer, an amplifier, and a recorder. A smaller bag placed between the air chamber and the leg is used for calibration by injecting a certain volume of air or water and measuring the change in the recording that is associated with that volume (Fig. 5.36). Parameters assessed include: (1) functional venous volume (VV), or the volume in the leg while the patient stands; (2) venous filling time 90 (VFT90), or the time required to achieve 90% of the VV; (3) venous filling index (VFI), or 90% VV/VFT90; (4) ejection volume (EV), or the volume expelled from the leg with one tiptoe motion; (5) residual volume (RV), or the volume at the end of 10 tiptoe motions; and (6) residual volume fraction (RVF), or RV/VV100 (Fig. 5.37).

Figure 5.36 The air plethysmograph consists of a long tubular polyvinyl-chloride chamber that surrounds the entire leg. This chamber is inflated to 6 mmHg and is connected to a pressure transducer, an amplifier, and a recorder. A smaller bag is placed between the air chamber and the leg for calibration.

(From Christopoulos DG, Nicolaides AN, Szendro G, et al: J Vasc Surg 5:148, 1987.)

Figure 5.37 Diagramatic representation of a typical recording of volume changes during a standard sequence of postural changes and exercise using the air plethysmograph. A, Patient in supine position with leg elevated 45 degrees; B, patient standing with weight on nonexamined leg; C, single tiptoe movement; D, 10 tiptoe movements; E, patient standing with weight on nonexamined leg; EF, ejection fraction; EV, ejected volume; RV, residual volume; RVF, residual volume fraction; VFI, venous filling index; VFT, venous filling time; VV, functional venous volume.

(From Christopoulos DG, Nicolaides AN, Szendro G, et al: J Vasc Surg 5:148, 1987.)

In a study of 22 patients with superficial venous insufficiency and nine patients with deep venous disease, VV was found to be elevated in 80% of patients.¹³⁰ VFT90 was greater than 70 seconds in normal limbs, 8 to 82 seconds in limbs with superficial venous insufficiency, and 9 to 19 seconds in limbs with deep venous disease. In normal limbs the VFI was less than 1.7 mL/second, in limbs with superficial venous insufficiency it was 2 to 30 mL/second, and in limbs with deep venous disease the value was 7 to 28 mL/second. Ejection fraction (EF) appeared to show better discrimination than EV. The RVF was 20% in normal legs, 45% in legs with superficial venous insufficiency, and 60% in legs with deep venous disease (Fig. 5.38). A linear correlation with r = 0.83 was present between RVF and AVP. In another study of 104 patients,^107,131 VFI was found to correlate with the incidence of sequelae of venous disease such as chronic swelling, skin changes, and ulceration (Table 5.5). In a third study of 205 limbs,¹³² the same authors found an increasing incidence of ulceration in patients with diminished EF and elevated VFI (Table 5.6) and found that the RVF showed a good correlation (r = 0.81) with the incidence of ulceration and AVP measurements.

Figure 5.38 Air plethysmography. Results of, A, venous filling time 90 (VFT90); B, venous filling index (VFI); C, ejected volume (EV); D, ejection fraction (EF). DVD, limbs with deep venous disease; N, normal limbs; SVI, limbs with superficial venous incompetence.

(From Christopoulos DG, Nicolaides AN, Szendro G, et al: J Vasc Surg 5:148, 1987.)

The real advantages of this method are its ability to quantitate reflux with the VFI and thus determine prognosis, and its ability to measure calf muscle pump function through the determination of the EF.^{107,130–133} Still, APG measurements should not be used in a vacuum. They should be combined with Doppler or duplex findings and clinical evaluation, since a great deal of overlap in values between normal and abnormal occur, decreasing the predictive value of abnormal APG measurements.¹³⁴ Neglen and Raju¹³⁵ demonstrated quite well in their evaluation of 118 limbs that VFI alone had a positive predictive value of 66% in separating clinical severity class 0 or class 1 from class 2 or class 3. VFI combined with information gleaned from duplex scanning had a positive predictive value of 83%.

Validation of use of APG in clinical practice has been achieved by some.^136,137 However, in clinical practice, the use of APG appears to be limited. Part of the problem is the difficulty in testing a large number of patients in a busy clinical setting. Another is the fact that the skin changes of severe chronic venous insufficiency are caused by many factors, and the data obtained by APG can represent only the hemodynamic factor and not the effects of leukocyte infiltration, activation, and leukocyte–endothelial interactions that produce the inflammatory response.¹³⁸

Perhaps the most carefully performed evaluation of the use of APG was accomplished under David Sumner’s direction in Springfield, Illinois.¹³⁹ In his report, he stated that, ‘We conclude that plethysmographic measurements of functional venous parameters do not discriminate well between limbs with uncomplicated varicose veins and limbs with ulcers or stasis dermatitis and that the venous filling index correlates poorly with the presence of incompetent veins and their diameters.’ Both duplex scanning and plethysmography seem to be necessary for a complete evaluation of limbs with chronic venous insufficiency.

Foot volumetry

Yet another method for evaluation of the functional state of the venous system is foot volumetry.^140–145 Introduced in the early 1970s, this technique has not earned a prominent place in phlebology, probably because of certain logistics of performing the test. However, it is necessary to have an accurate way to measure leg swelling either for evaluation of chronic venous disorders (day-to-day edema measurement) or calf pump function assessment.¹⁴⁶ The patient stands with their feet in an open water-filled plethysmograph (Fig. 5.39). The water level is monitored by a photoelectric sensor, and changes in foot volume are continuously measured, first while the patient is standing still, then during the performance of 20 knee bends, and again while standing still. The parameters measured include the volume of blood expelled from the foot during exercise, the flow rate after exercise, and the time required for half and then full refilling to occur. Norgren et al¹⁴³ have shown good correlation between foot volumetry and invasive venous pressure measurements in control subjects (r = 0.662) and in patients with varicose veins (r = 0.760) but poor correlation in patients with deep venous valvular insufficiency (r = 0.410). In their study, venous pressure measurements differed significantly in patients with varicose veins and controls but were similar in patients with primary varicose veins and those with deep venous valvular insufficiency. However, with the use of foot volumetry, there were significant differences between all three groups. Thus, although it is possible that foot volumetry is inaccurate in this important categorization, it is likely that this technique is more sensitive in distinguishing these groups than are venous pressure measurements.¹⁴⁴ It has been shown that both the volume expelled with exercise and the refilling time increase after treatment of varicose veins.¹⁴⁵ Therefore, this test could be used to evaluate the success of a particular treatment, to follow the effect of different stages in treatment, and to monitor the severity of chronic venous insufficiency. It does not, however, allow localization of a particular site of reflux, thus limiting its usefulness for presclerotherapy evaluation when compared with other methods (Table 5.7–5.10, Fig. 5.40).

Figure 5.39 The apparatus for foot volumetry consists of an open water-filled plethysmograph that allows continuous measurement of foot volume at rest and during exercise through monitoring of the water level by a photoelectric float sensor.

(Courtesy Lars Norgren, MD)

Table 5.9 Relevance of investigations according to considered abnormalities – associated investigations

Figure 5.40 Organization chart of venous investigations work-up in case of suspicion of post-thrombotic syndrome (PTS).

(From Perrin M, Gillet JL, Guex J-J: Encycl Méd Chir. Editions médicales et scientifiques, Paris, 2003, Elsevier SAS, Angéiologie 19-2040 [12p].)

Examination of deep veins

Duplex ultrasound is the standard for examination of deep veins of the leg. A reflux duration of at least 0.5 seconds after the release of calf compression identifies valvular insufficiency.⁵⁸ Descending venography provides accurate information on the state of the deep venous valves. Although its invasiveness, associated risks, and pain make it a much less attractive option for routine use, occasionally it provides information unobtainable with other studies (Fig. 5.41). Photoplethysmography detects the presence of valvular insufficiency, and compression of the superficial veins (either manually or with a tourniquet) allows differentiation between superficial and deep venous reflux; however, PPG cannot localize the reflux to the level within the deep system (femoral versus popliteal, etc.). When both superficial and deep venous reflux are present, PPG will allow the determination of the relative importance of each segment. Although ascending venography was once considered the gold standard for the diagnosis of acute or chronic deep venous obstructive disease, most institutions now use B-mode ultrasound or color duplex scanning in everyday clinical practice. Magnetic resonance venography may find a place in the diagnostic armamentarium as well, since it has been found to be as accurate as duplex scanning in the diagnosis of DVT.¹⁴⁸

Figure 5.41 A, This 36-year-old man with recurrent venous ulcers was noted to have numerous large varices in the anteromedial thigh. A duplex scan was complicated because of the large number of veins. B, Descending venography successfully shows an absent or occluded segment of the common femoral and superficial femoral veins with a large number of collateral veins around the obstruction.

Descending venography detects deep venous valvular reflux but, again, the duplex scanner offers the additional advantage of quantifying the reflux by determining flow velocities. The finding of deep venous valvular insufficiency is worrisome because it may be associated with chronic venous obstructive disease, which may give rise to venous claudication,^42–44 since there are a small number of patients who rely on their dilated superficial channels for venous return. This has been determined using strain gauge plethysmography¹⁴⁹ and most likely may be assessed with PPG as well. Impairment of VRT with the tourniquet might caution the examiner to avoid treatment. Alternatively, the simplest and most practical test is to place a 30- to 40-mmHg compression stocking on the patient for 24 hours. The development of pain while walking contraindicates sclerotherapy and suggests the need for a venous bypass procedure. Using APG, Spence et al¹⁵⁰ found that compression therapy in patients with venous claudication caused a deterioration in the EF and/or AVP as measured by RVF. Noninvasive tests do not provide sufficient sensitivity if there is genuine concern about venous claudication. The examiner must proceed with invasive pressure measurements, such as the arm–foot vein pressure differential or the foot vein pressure elevation after reactive hyperemia, as described by Shami et al.¹⁰ Deep venous valvular insufficiency has also been found to reduce the likelihood of successful long-term sclerosis of the main saphenous trunk.⁶⁴

Examination of saphenous vein trunks

Duplex ultrasound is now the standard for examination of saphenous vein trunks. Historically, Thomas and Bowles¹⁵¹ found that Doppler ultrasound grossly overdiagnosed incompetence when compared with venography, and they recommended that all GSV be examined with venography before ligation and stripping. One reason for this is the fact that Doppler examination is ‘blind’; thus, dilated tributaries of the saphenous vein or pelvic varicosities may be mistaken easily for the GSV. This was addressed in two early studies that compared the results of continuous-wave Doppler examination with those obtained with duplex scanning.^66,67 The researchers found that in the examination of the GSV, Doppler was no better than 77% sensitive and 83% specific compared with the duplex scan. In a more recent study using duplex scanners with even greater sensitivities, DePalma et al¹⁵² found a sensitivity of 48%, specificity of 83%, positive predictive value of 83%, and negative predictive value of 44% in the determination of GSV reflux. By obtaining duplex scans preoperatively, 10 limbs out of 80 were spared GSV stripping.

On the basis of these data, it might be argued that all patients with GSV varicosity should undergo duplex scanning before treatment. However, the cost of this testing is high, and the equipment is not readily available to many clinicians. Therefore, at this time, Doppler examination offers the physician the most practical approach to this important segment of the venous system and the duplex scan certainly may be obtained if there is any doubt about the diagnosis.

The Doppler examination of the junction of the saphenous trunks with the deep veins (SFJ and SPJ), and the distinction between reflux through these junctions versus reflux through the deep veins themselves, is often difficult and a common source of error. In fact, studies using Doppler ultrasound have quoted an incidence of deep venous valvular reflux from 5% to 30%,^27,28,64 a range that is most likely partially determined by the difficulty of the examination and not solely by differences between the populations examined. The distinction between junctional and actual deep venous reflux is important for several reasons. First, Schultz-Ehrenburg^28,64 found that patients with deep venous valvular incompetence fared far better with a surgical approach to their disease than with treatment that was limited to sclerotherapy. Thus, the accuracy of this portion of the examination has a direct application to the treatment plan. In addition, patients with deep venous valvular insufficiency should be questioned regarding a history of iliofemoral thrombosis and possible chronic venous obstructive disease, which might contraindicate treatment of their GSV. Finally, it is possible to have only deep venous valvular insufficiency with a normally functioning saphenous vein. Thus, without this differentiation, a patient may be sent for treatment of a normal superficial vein. The technique of examination is quite simple. The Doppler probe may be placed over the site of the SFJ or over the femoral vein with the patient standing or supine, and the patient is asked to perform the Valsalva maneuver. The procedure is then repeated with the GSV firmly compressed below the Doppler probe. If reflux still can be heard after compression is applied, the examiner assumes that the reflux is in the femoral vein. In contrast, if the reflux is obliterated with this maneuver, the retrograde flow is only through the SFJ and not through the femoral vein itself.

Examination of tributaries of the saphenous trunks

Duplex ultrasound is now the standard for examination of tributaries of saphenous vein trunks. The examination of the tributaries of the saphenous trunks focuses on two major questions: (1) to which saphenous trunk does the tributary belong, and (2) is there reflux of blood from the deep vein directly into the tributary? Both answers may be obtained either by physical examination maneuvers or the Doppler or, most definitively, with duplex ultrasound. The origin of any tributary may be assessed with the percussion test, in which the palpating hand is placed gently over the tributary while the GSV or SSV is percussed with the other hand (or vice versa). The palpation of an impulse with percussion of a particular trunk localizes the origin of the tributary to that trunk. Alternatively, a modified Trendelenburg test supplies this information. The patient is asked to lie down with the leg elevated to nearly 90 degrees. The proximal GSV or SSV is then firmly compressed, and the patient is asked to stand. If the varicose tributary remains empty and fills only when the compression is released from the GSV, the origin of the tributary is localized to that system. The presence of reflux from the deep system may then be discovered by using the cough test, in which the palpation of an impulse over the tributary when the patient coughs implies reflux of blood from the deep system through incompetent valves into the tributary.

As mentioned previously, although the Trendelenburg test is reasonably accurate, the cough and percussion tests are now considered confirmatory because the Doppler provides a more accurate answer to these questions. Placement of the Doppler probe over the tributary while intermittently compressing or percussing either the GSV or SSV allows determination of the origin of the tributary (Fig. 5.42). Listening for reflux while the patient coughs or performs the Valsalva maneuver uncovers connections to the deep system (since there should be no reflux unless there is a pathway directly to the deep vein that is unobstructed by incompetent valves). The applicability of the first piece of information is obvious. Careful evaluation must then be directed to that particular incompetent saphenous trunk to achieve sclerosis of the tributary as well. However, the connection of the tributary to the deep system must be explored further because the exact route that the blood has taken from the deep to the superficial system must be defined. If the connection is simply through the SFJ or SPJ, again the treatment directive is apparent. On the other hand, if the connection is actually through a perforating vein or another tributary,⁶⁴ treatment must be aimed at that particular vein and, perhaps, treatment of the saphenous trunk may be unnecessary. Manual occlusion of the involved saphenous trunk at its proximal end, followed by repeat examination, offers this important differentiation. If this occlusion causes the obliteration of reflux with the cough or Valsalva maneuver then the blood must have flowed through the SFJ or SPJ. If, on the other hand, this maneuver does not change the result of the test then the saphenous trunk is an important conduit and the perforating vein must be the important route.

Figure 5.42 The origin of a particular varicosity may be defined by listening over the dilated vein while alternately compressing the, great saphenous vein (A) and, small saphenous vein trunks (B).

The importance of duplex scanning in patients with varicose disease has been verified by studies in which clinical examination, duplex ultrasound, and plethysmography have been compared.¹⁵³ These studies have revealed that quantitative plethysmography was not particularly helpful because of its nonspecificity. The duplex scan, however, was able to identify patients without SFJ reflux and could ascribe varicosities to tributary incompetence. Such incompetence would be the target for sclerotherapy or isolated ambulatory phlebectomy.

Examination of perforating veins

The perforator segment of the venous system is probably the most mysterious because of its variability, the difficulty of locating perforators even under direct visualization in the operating room, and the overwhelming importance ascribed to perforating veins in the development of varicose veins and the skin changes associated with chronic venous insufficiency.¹⁵⁴ It is no wonder, therefore, that no consensus exists about what constitutes the best method for examination of perforating veins and their valvular competence. Nearly every technique, including venography, Doppler, duplex, thermography, fluorescein injection, and physical examination of fascial defects, has been used with varying degrees of success. Complicating the evaluation of each method is the fact that all are compared with later surgical findings, which most likely also miss many IPVs and which are impossible to standardize. Underscoring the current difficulties in this aspect of venous diagnosis are data that show that the number of IPVs detected per limb, in studies of the various diagnostic methods ranges from 1 to 4, whereas anatomic studies have shown a range of 1 to 14, with an average of 7.³² Thus it is still impossible to test the exact sensitivity and accuracy of each method. At best, the examiner may miss a great deal of important pathology. In spite of the pitfalls and limitations of current diagnostic methods, examination for IPVs is crucial and usually productive. As mentioned previously, in a study of 901 limbs with varicose veins, 90% were found to have incompetent perforators.³² Of interest, only 9% of the perforators were found in the thigh. Thigh perforators may be either single or multiple and may occur anywhere from just proximal to the patella to just below the SFJ, with most being single and located in the middle third of the thigh.¹⁵⁵ In evaluating patients with IPVs in the lower leg, Dodd¹⁵⁶ found that 45% were associated with incompetence of the GSV, 15% with incompetence of the SSV, and 2% with an IPV in Hunter’s canal. Therefore, any patient with significant truncal varicosities, as well as those with signs of chronic venous insufficiency, should undergo evaluation for perforator valvular insufficiency.

Historically, the most important and probably the most commonly used technique for detection of outward flow through perforating veins was that of clinical examination. With its ability to detect 50% to 70% of IPVs, clinical examination should be the first step in the evaluation. Other techniques have been studied extensively, such as thermography,^{36,39,157,158} fluorescein injection,^159,160 and ascending^36,37,159 and intraosseus³⁹ venography, generally demonstrating accuracies of between 60% and 90%. Unfortunately, the required instrumentation makes these techniques impractical for most practitioners. The techniques can be used, however, when perforator disease is strongly suspected but has escaped localization by other methods.

Ultrasound technology can be helpful and is associated with greater ease and lower risks than the other methods. Probably the most effective method of locating perforator veins is to inject a low concentration of foamed detergent sclerosant and follow its flow into perforating veins. Doppler evaluation of perforator incompetence provides a diagnostic accuracy of 60% to 90%^37,80,82,160 and definitely improves with experience. In one study of 39 legs,³⁷ its accuracy improved from 60% to 87% when it was combined with clinical examination, thus making this combination of techniques well suited for routine clinical practice. Duplex scans are extremely useful in visualizing the site(s) of IPVs (Fig. 5.43) and may be considered if the examiner is otherwise unable to localize a vein in a suspected area and has the necessary equipment.

Figure 5.43 Incompetent perforating veins can usually be discerned with duplex scanning. A, Gray scale, longitudinal scan. B, Color image showing reflux. GSV, great saphenous vein; PERF, perforating vein; SFV, superficial femoral vein.

The clinical significance of outward flow through perforating veins has long been debated, and the physiologic to-and-fro movement of blood through perforating veins in normal feet is well accepted. Thus, the finding by Sarin et al¹⁶¹ that the direction of blood flow within medial calf perforators can be either inward or outward in legs without venous disease is quite interesting. They observed outward blood flow in 21% of medial calf perforators in normal limbs during compression of the foot with a cuff inflated to 60 mmHg. However, during the relaxation phase (distal cuff deflation), flow occurred in 33% to 44% of perforators in limbs with venous disease but in none of the perforators in limbs without venous disease. Thus, this criterion may allow the first true differentiation of pathologic flow within perforating veins.

Differentiation of the relative contribution of deep and superficial reflux

Photoplethysmography, with and without compression, is especially useful in the setting of both deep and superficial venous disease; it is also simple and inexpensive to use. If the Doppler examination has disclosed that both the superficial (GSV or SSV) and deep veins (CFV or popliteal) are incompetent, this test can help to determine the relative importance of each segment of the venous system and whether correction of the superficial problem offers the patient sufficient benefit (given the persistent deep vein reflux) to be worth the potential risks of treatment. This is exemplified by the case of a 40-year-old woman with congenital absence of valves within her femoral veins and a history of bilateral leg edema, lymphedema, and more recently the progressive enlargement of varicosities of her main long saphenous trunks. Although it was believed that her main problem was a deep venous defect, the application of this relatively simple examination scheme allowed a more precise understanding of her condition. By manual compression of the patient’s GSV, her initial refilling time of 8 seconds lengthened to 19 seconds, indicating a significant contribution by her superficial system to her pathologic hemodynamics. In further testing of these findings, a duplex scan was performed, showing that the peak velocity of reflux flow through the GSV was greater than 33 cm/second, whereas that through her CFV was only 9.5 cm/second. The patient underwent high ligation and division of her GSV, and postoperative sclerotherapy. Marked improvement in the discomfort and the edema in her legs resulted, and she was able to reduce the use of her Lymphapress and periodically able to wear hose with less compression without the disabling aching in her legs that she had experienced previously.

Other examples of the usefulness of the PPG are illustrated below:

Evaluation of the origin of recurrences after ligation and stripping

Duplex ultrasound is considered to be the best method to evaluate recurrences after ligation and stripping. There are several noninvasive or minimally invasive methods that provide information helpful to understanding the remaining connections and therefore the necessary sites of treatment. Lofgren,¹⁷ in his study of 510 operations performed on patients with recurrence after ligation and stripping, found most of the recurrences to be the result of inadequate surgery. Either treatment of a dilated tributary with the actual saphenous trunk left untouched or ligation distal to the SFJ/SPJ are the usual findings.

Lofgren felt strongly that all patients with recurrence should be explored surgically, thus obviating the need for an imaging procedure. Since many of these patients will be found to have problems amenable to sclerotherapy alone, this is not a very satisfactory approach, and the physician first should attempt to define the anatomy of the recurrence before proceeding with treatment decisions.

The approach to the kind of patient just mentioned begins in the same way as the approach to any patient with involvement of the saphenous trunk. The palpation of the GSV or SSV is attempted, followed by the Doppler examination for reflux. It is always possible that the dilated vein noticed by the patient may simply be, in fact, a collateral that is functioning normally and does not need to be treated. Once reflux through the vein has been documented, a Valsalva maneuver will demonstrate whether this vein is still in connection with the deep venous system. If not, sclerotherapy generally may be used successfully. If reflux is heard with a Valsalva maneuver, the patient may then be approached as if he or she was presenting de novo with SFJ or SPJ reflux. Historically, venography has been used in this situation and provides a good image of the exact connection of the recurrent varix. However, duplex scanning provides excellent images without the associated risks of the contrast media and radiation, and it has been recognized as the gold standard for evaluation of recurrences.¹⁶²

Evaluation of vulvar varices

Vulvar varices generally arise from the pudendal or iliac veins and require treatment only of the varices themselves. In some cases, however, they connect directly with the long saphenous system. Therefore, before treatment, the presence of an incompetent SFJ should be sought, since long-term control of these varices requires control of the SFJ if blood is refluxing through it into the vulvar veins. The technique for this determination has been described previously. The exact connection may also be determined by varicography (Fig. 5.44). Since the association between pelvic varices (often complicated by pelvic congestion syndrome) and inguinal varices is common, a retrograde selective catheterism and venogram of pelvic veins will frequently help to solve both problems at the same time by means of specific endovenous treatment (association of coils and foam sclerotherapy).^163–165

Figure 5.44 A, Vulvar varix (arrow). B, Varicography may be used to define its origin.

(Courtesy Jeffrey Weisfeld, DO)

Venography

The most serious disadvantages of venography are its invasive method, the frequent development of superficial phlebitis as a result of the procedure, and a 5% to 10% incidence of allergy to the contrast medium. The latter complications have been significantly reduced through the introduction of newer nonionic contrast media,¹³ and venography continues to find some use in the diagnosis and treatment planning of venous disease. It also has great use in the evaluation of groin and pelvic recurrences, including vulvar varicosities.¹⁶⁶ Four techniques have been described: ascending venography, descending venography, intraosseous venography, and varicography.

A variation of venography involving the injection of fluorescein into a vein on the dorsum of the foot has been used for the localization of incompetent ankle perforating veins.¹⁶⁷ This test is performed by placing a 2.5-cm cuff, inflated to 80 mmHg, just above the malleoli. The leg is elevated to 90 degrees, and the patient is asked to plantarflex the foot 10 times. A second 13-cm cuff is then inflated to 120 mmHg just above the knee, and the leg is lowered. Five mL of aqueous fluorescein is then injected into the distal portion of the foot, and an ultraviolet light is directed toward the leg in the darkened room. A second set of 10 plantar flexions is performed, drawing the solution into the deep veins and outward through any incompetent perforators. This is reflected on the skin surface as a circle of yellow–green fluorescence, 1 to 2 cm in diameter, within 30 seconds to 2 minutes. In 37 legs studied, this method had a 96% accuracy, identifying 50 of the 52 perforating veins later found to be incompetent at surgery, with two false-negatives and four false-positives.

Ascending venography

Ascending venography¹³ is performed by injecting the contrast medium into a superficial vein on the dorsum of the foot after a 2.5-cm tourniquet has been placed around the ankle to prevent flow through the superficial venous system. This forces the contrast to enter only the deep veins and allows clearer visualization of the deep system. Fluoroscopic imaging with the patient in various positions allows the deep veins, from the foot to the lower segment of the inferior vena cava, to be examined for the presence of thrombi (Fig. 5.45A). Passage of the contrast into the perforating veins is abnormal and diagnostic of valvular insufficiency (Fig. 5.45B).³⁸ The addition of a Valsalva maneuver shows competent venous valves and defines bicuspid structures with a concentration of contrast media in their sinuses, and it may obviate the need for descending venography if this procedure were to be considered later. Ascending functional venography requires the patient to plantarflex the foot, thus forcing the contrast into the superficial veins through any IPVs during muscle relaxation.⁷

Figure 5.45 Ascending venography demonstrating, A, thrombus as a space-filling defect (arrowhead) and, B, incompetent perforating vein (arrowheads).

Descending venography

Descending venography involves injection of the contrast into the femoral or the popliteal vein with the patient lying supine or tilted head-up and performing a Valsalva maneuver. Valvular insufficiency is readily demonstrated because the contrast flows rapidly in a retrograde direction. Five grades of reflux have been described (Fig. 5.46).^61,168 One of the disadvantages of this technique is that the demonstration of reflux at a given level relies on the presence of reflux at the higher levels. Therefore, using descending venography alone, the examiner might miss isolated incompetence of tibial veins or gastrocnemius veins, both of which have been shown to be responsible for the production of significant symptoms (see Chapters 3 and 4).^169,170

Figure 5.46 Descending venography may demonstrate five grades of reflux: grade 0, no reflux below the confluence of the superficial and profunda femoris veins; grade 1, reflux into the superficial femoral vein but not below the middle of the thigh; grade 2, reflux into the superficial femoral vein but not through the popliteal vein; grade 3, reflux to just below the knee; grade 4, reflux to the ankle level.

Dynamic popliteal phlebography¹⁷¹ had been the latest, and successful attempt to improve phlebography, especially for analyzing deep venous function and structure. It has, however, been rendered obsolete by ultrasound duplex scanning.

Varicography

Varicography (Fig. 5.47) is a very helpful technique in which the contrast agent is injected directly into the dilated varix, showing the extent of the varicosities and their connection with other superficial, perforating, and deep veins.^{13,166,173,174} The direction of blood flow, and therefore the competence of valves, is not discernible, although other criteria have been found to correlate with valvular insufficiency. For instance, if a perforator is greater than 3 mm in diameter and is seen to be tortuous, it is assumed to be incompetent.¹³ When other methods, such as duplex scanning, fail to demonstrate the proximal connections of a varicosity (because of obesity of the patient, masses of varicosities in the area, etc.), varicography provides a relatively simple way of showing this anatomy clearly (Fig. 5.48).

Figure 5.47 Varicography. Injection directly into the varix may demonstrate the origin of a recurrence in the groin after vein stripping.

(From Lea Thomas M, Mahraj RPM: Phlebology 3:155, 1988.)

Figure 5.48 A, This patient presented with a recurrent varicosity 25 years after great saphenous vein (GSV) stripping. Duplex ultrasound showed no reflux at the level of the saphenofemoral junction and no evidence of a GSV but was unable to demonstrate the connection of the varicosity to the deep venous system. B, Varicography clearly showed the proximal site of connection as well as sites of additional incompetent perforating veins.

Thermography

Infrared thermography is based on the fact that infrared waves radiate from the skin surface in proportion to the temperature of that surface.^175,176 It is possible to scan the surface with an infrared detector and create an image in which gradations of white and black or color reflect degrees of heat. Two identical symmetric skin areas of the body should be at the same temperature unless certain factors are present. These factors include structural abnormalities of vessels (dilation and incompetence), abnormalities of vascular control, local effects on vessels, changes in thermal conductivity of the tissues, and increased heat production of the tissues. When veins are dilated, such as with varicose veins or with an underlying arteriovenous communication, the overlying skin is warmer because of the accumulation of the extra volume of blood in the dilated vein. Similarly, when venous valves are incompetent, the reflux of blood from the more central CFV down the GSV (when the limb is lowered), or outward from the warmer deep veins through a perforating vein when the calf muscle is activated, produces a rise in skin temperature; this may be visualized on the thermograph as a white, or ‘hot’, spot (Fig. 5.49). In fact, this technique may be used to localize the site of an IPV (see Chapter 3).³⁹ After the general distribution of thermal patterns is recorded in the standing position, the leg is elevated for 1 minute to drain the veins, and the leg temperature is lowered with a cold, wet towel or a fan for 5 minutes. A tourniquet is placed around the proximal thigh to occlude the superficial veins, and the patient is asked to stand. Areas of rapid rewarming suggest possible sites of IPVs. These areas are re-examined after tourniquets are placed above and below each site. The segment in question is again cooled, and the appearance of a hot area within 60 seconds of standing (in the case of a thigh perforator) or of calf muscle action (in the case of a lower leg perforator) identifies the site of an incompetent perforator. Of 84 IPVs later found at operation, thermography correctly identified 79 (94%). The five that were missed by thermography were found at surgery to be very small in diameter or in close proximity to a larger incompetent perforator that was correctly identified. Of the 12 false positives, 4 were caused by inadequate surgical exploration of the area, and the others were the result of heat changes from communicating sites of superficial veins or from the penetration of the GSV into the deep fascia of the thigh. The relationship of arteriovenous fistulas to varicose veins remains controversial, and thermography has been validated as a technique for identifying arteriovenous fistulas when they are present.¹⁷⁷

Figure 5.49 Positive thermograph. The presence of an incompetent perforating vein may be indicated by a ‘hot’ spot.

(Courtesy K. Lloyd Williams, MD, CHIR, FRCS.)

Near infrared imaging

Infrared imaging can be used to visualize superficial reticular veins. Bustos et al showed that this could be performed either with the use of a red light source close to 700 nm or an infrared night-day vision camera system (Vision Viewer Gen 3 (Night Vision Experts, Buffalo N.Y.). Both of these systems allow the operator to visualize veins 2 to 3 mm in depth.¹⁸⁰ A more elaborate infrared imaging device, the Luminetx VeinViewer (Luminetx Corp. Memphis, Tenn.), was used by Miyake et al and found to be useful in treating reticular veins.¹⁸¹ A study of 23 subjects with varicose veins and telangiectasia demonstrated that 100% had feeder veins which could be detected by the VeinViewer. These visualization techniques may be useful in allowing more efficient treatment of superficial veins. Near-infrared fluorescence venography using indocyanine green has also been demonstrated to be helpful in visualizing superficial veins prior to ambulatory phlebectomy.¹⁸²