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CHAPTER
12
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Duplex ultrasound scanning for chronic
venous obstruction and valvular incompetence
Pedro J. Furtado Neves, Rafael D. Malgor, and Nicos Labropoulos
12.1 INTRODUCTION
Venous obstruction and reux are the two pathologies that
lead to venous hypertension, which causes the sequelae of
chronic venous disease (CVD). Despite the high prevalence
of CVD and the number of studies that have been performed in this area, the etiology of CVD is poorly understood (1). The challenge to the clinician is to nd a method
of reliably evaluating a patient for CVD. The physical
examination is useful. Many of the signs and symptoms of
CVD can be detected by physical examination, but physical
examination alone is inadequate.
Phlebography, plethysmography, and duplex ultrasound (DUS) are the main methods for the evaluation of
the venous system. Computed tomography and magnetic
resonance imaging have also been utilized lately in CVD
workups, especially in cases where iliocaval obstruction is
suspected (2). Plethysmography is used in the assessment
of the amount of reux, the efciency of the calf muscle
pump, and obstruction. Phlebography is used when there is
a need for endovenous therapy and deep vein reconstruction. Plethysmography is also recommended in patients
with advanced CVD if duplex scanning does not provide
denitive information on pathophysiology (2). DUS has
become the test of choice for the evaluation of CVD in
most patients, as it is safe, noninvasive, cost-effective, and
reliable. Although the evaluation of acute venous pathology is discussed in Chapter18, it must be mentioned that
such pathology can recur in new or previously affected vein
segments and can worsen the clinical severity of CVD.
The CEAP classication was developed by the American Venous Forum in 1994 and revised in 2004 to delineate
the severity of CVD, improve standards of reporting, and
develop treatment plans for the various stages of the disease (3, 4). It relies on the four components of clinical signs
(C), etiology (E), anatomy (A), and pathophysiology (P).
Additionally, in 2020, the CEAP classication was modied
to incorporate corona phlebectatica as a distinct clinical
subclass (C4c) and introduced the “r” modier for recurrent varicose veins and ulcers (4). Amore detailed venous
score system, the revised Venous Clinical Severity Score
(r-VCSS), has also been increasingly utilized to grade the
severity of CVD in terms of impact on the patient’s daily
living conditions (5). The VCSS is composed of 10 categories which mainly consider the degree of pain, amount of
DOI: 10.1201/9781003328971-14
varicose veins, degree of edema, skin pigmentation, inammation, induration, number of active ulcers, duration of
active ulcers, and the use of compression stockings. Each
of the parameters receives a score from 0 (absent) to 3
(severe), thus ranging from 0 to 30. It is intended as a tool
for evaluating change before and after intervention. Additional patient-reported outcome measures (PROMs) have
been increasingly studied for evaluating success after intervention (6, 7), and there are several validated questionnaires, such as the Aberdeen Varicose Veins Questionnaire
(AVVQ), the Chronic Venous Insufciency Questionnaire
(CIVIQ), and the Venous Insufciency Epidemiological and
Economic Study quality of life/symptoms (VEINES-QOL/
Sym) (8–10). Both the physical examination and diagnostic
tests are employed in order to report the patient’s condition
before and after treatment.
12.2 DUPLEX ULTRASOUND
The choice of the ultrasound probe is important. The pulsewave Doppler of a 4- to 12-MHz linear array transducer
is ideal for the examination of most veins. Other multifrequency arrays can be used as well. The more supercial
veins can be evaluated using higher-frequency probes that
give better resolution but sacrice depth of penetration.
The deep veins and veins in obese patients are evaluated
using a 5-1-MHz curvilinear probe that provides better
depth of penetration. Lower-frequency probes are also used
to evaluate the venous system in the pelvis and abdomen
and register low ow better. Curvilinear lower-frequency
transducers should also be utilized whenever the depth of
imaging is >6cm (large limbs).
During imaging, low-ow settings are most used. The
pulse repetition frequency (PRF) is set at 1500 Hz or lower.
In cases of vein stenosis or arteriovenous stula, the PRF
is set higher since the ow velocity is signicantly elevated
in such situations. The focus is set with the posterior wall
(far wall in relation to the skin) to enable better lateral
resolution in the eld of imaging. The vein lumen should
be set to appear dark in the absence of stasis and thrombosis. The time gain compensation is set according to the
echogenicity and depth of the relevant tissues to perfect the
imaging of the pertinent pathology. When obtaining velocity waveforms, the gain is set to have a dark background
115115
116 Chapter 12 DUS scanning for chronic venous obstruction and valvular incompetence
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to avoid overestimation. If the signal is weak because
of depth, the gain is increased accordingly. The angle of
insonation in the venous system is often set at 0 degrees.
However, because most veins run parallel to the skin, if
a precise velocity is needed, then the angle must be corrected to be under 60 degrees to the ow channel in order
to avoid velocity misrepresentation. This is because the
Doppler frequency equation takes into account the cosine
of the angle, and the cosine of 90 degrees is 0, and the
cosine of 0 degrees is 1 and of 180 degrees is –1. Therefore,
at a 90-degree angle, the Doppler effect is inexistent, and
at a 0- or 180-degree angle is maximized. Any angle less
than 60 degrees is deemed acceptably accurate for velocity
calculation, and velocities acquired with angles closer to 90
degrees are subject to error.
The examination room conditions should also be conducive to obtaining optimal results. The room should be
warm and comfortable, and a warm gel must be utilized on
the skin in order to ensure that there is no spasm of veins at
the time of examination and that the veins are at their natural size. Evaluation of infrainguinal veins for reux and
chronic obstruction should be done on standing. Sitting
position is used if the patient cannot stand for long. These
positions are more physiologic, the veins are dilated, and
testing is more accurate assuring the veins. Patient hydration on the day of examination and its impact on venous
physiology are also important factors to consider and are
frequently overlooked.
12.3 OBSTRUCTION
Obstruction in the venous system can occur due to extrinsic
and intrinsic pathologies. Tumors, hematomas, cysts, aneurysms, and musculoskeletal structures can cause extrinsic
vein compression. However, the most common cause of
obstruction is venous thrombosis. Its diagnosis is critical,
as deep vein thrombosis (DVT) is obviously a signicant
cause of long-term morbidity and premature mortality in
those aficted with the disease.
The long-term consequences of DVT are devastating in
terms of numbers and cost of care. Post-thrombotic syndrome (PTS) is a term that is used to describe the sequelae
of CVD following DVT. The typical ndings are pain, a
burning sensation, itching, varicose veins, chronic limb
swelling, skin discoloration, and ulceration. Recanalization
of the vein following DVT leads to chronic venous wall
changes and valvular destruction and dysfunction, which
lead to the ndings of PTS. After a single episode of DVT,
the incidence of PTS has been reported to range from 23%
to 79%. Alarge prospective study showed an incidence of
about 25% at 5years (11). Ipsilateral recurrent DVT has
been shown to increase the odds for developing PTS by
six times (11). Rates of PTS also vary depending on the
venous segment aficted, with more proximal DVT having
a greater risk of PTS (12). Due to this high risk of developing PTS, more recent guidelines have advocated for early
thrombus removal in the setting of DVT, when the patient’s
clinical conditions and life expectancy permit, particularly
in the iliofemoral segment (13). The use of pharmacomechanical catheter-directed thrombolysis has been shown to
result in less residual thrombus but did not reduce venous
valvular reux (14), but more modern mechanical thrombectomy devices that have been developed are associated
with better maintenance of valvular function (15, 16). The
sensitivity and specicity of DUS for identifying thrombosis
is >95% proximal to the knee, whereas the accuracy may
decrease in the below-knee segment (17). The evaluation of
functional obstruction cannot be achieved with DUS, as it
assesses a single vein segment at a time. Unfortunately, it is
difcult to measure functional obstruction since there are
no validated tests to quantify it.
Duplex techniques for the evaluation of CVD are like
those used in the evaluation of acute venous thrombosis,
with the added attention to detailed description of reux
duration, location, and associated collateral or perforating veins. In chronic disease states, the major veins might
be chronically obstructed. Collateralization and recanalization may also occur. The major veins are seen near the
corresponding artery. If a vein is seen more than 1 cm
away from the artery, one must consider the possibility
of a dilated collateral vein. Normal venous Doppler signals are obtained in cases where full recanalization has
occurred or in the presence of duplicated veins that were
unaffected by the thrombotic process. The popliteal vein
is duplicated in 35%–40% of people and occasionally is
triplicated. The femoral vein in the thigh is duplicated in
about 25%–30% of people, and this duplication may have
different patterns along the course of the vein (18). The
veins in the calf are often paired around the corresponding artery. Asingle calf vein or a triplication may also be
found. Aplasia of the posterior tibial veins has also been
reported. In cases of venous duplication or aplasia, direct
visualization, attention to detail, and experience with the
ultrasound techniques and anatomy are invaluable for
accurate interpretation. In patients with previous DVT, the
technician must be vigilant when scanning the previously
affected and the contralateral limb for recurrence of DVT
or chronic venous wall changes resulting from the thrombotic event. Risk factors for recurrent DVT are previous
ipsilateral DVT, age >65years, residual thrombus, or previous iliofemoral involvement (11, 17, 19). Knowing these
risk factors aids the operator when carefully seeking signs
of recurrent DVT, such as thrombus found in a new location, thrombus extending >9cm farther in the vein, a previously recanalized segment that is not compressible, and
thrombus thickness ≥2mm for calf veins and ≥4mm for
proximal veins (20).
Venous ultrasound studies are reasonably well standardized and may be performed in two positions. Preferentially, the patient should be examined in an upright
position; however, when patient characteristics make
a standing examination unfeasible, the reverse Trendelenburg position may be appropriate (21). The knee is
bent and externally rotated. The examination is started
below the inguinal ligament at the common femoral vein
and saphenofemoral junction (SFJ). The probe is placed
in transverse direction to the vein and compression is
applied. The probe is then turned longitudinally to evaluate ow and augmentation via compression of soft tissues distal to the vein, encouraging increased venous ow
proximally (21). Alternatively, for evaluating reux of the
common femoral vein or SFJ, the Valsalva maneuver may
be used to elicit reux (21). The veins are examined in
12.3 Obstruction 117
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3- to 5-cm intervals. In a similar manner, all of the deep
veins of the leg, including the femoral, deep femoral, popliteal, peroneal, soleal, gastrocnemius, and posterior tibial
veins, are examined for obstruction. An examination of
the anterior tibial veins is not routinely performed due
to their low incidence of thrombosis unless local symptoms or trauma to the anterior leg compartment area are
present. The supercial veins, including the great saphenous vein (GSV) and small saphenous vein (SSV), are then
evaluated. Finally, in cases of obstruction or ndings concerning for cranial outow obstruction, it is important
to check the iliac veins and the inferior vena cava (IVC).
In abdominal and pelvic veins, mainly ow is evaluated
since compression can be difcult and uncomfortable for
the patient. Anormal venous ow is phasic with respiration and is augmented with distal compression or is
stopped with the Valsalva maneuver (22). Asymmetry in
ow velocity and waveform patterns at rest and during
ow augmentation in the common femoral veins indicate
proximal obstruction (23). However, the absence of such
asymmetry does not exclude obstruction. Therefore, when
iliocaval obstruction is suspected, the full extent of these
veins must be imaged.
The presence of stenosis, usually from extrinsic compression, is recognized by a mosaic color pattern that
denotes post-stenotic turbulence, abnormal Doppler waveform and aliasing due to high velocities at the area of stenosis, slow ow, spontaneous contrast, and vein dilatation
prior to the stenosis (24). The vein diameter reduction can
be measured by planimetry, comparing the smallest lumen
to the normal lumen. Peak vein velocity ratios comparing
intrastenotic to prestenotic peak velocities or comparing
post-stenotic to prestenotic peak velocities can be calculated. In patients with a pressure gradient across the stenosis ≥3 mmHg, the peak systolic velocity (PSV) ratio has
been shown to be >2.5. This is particularly useful when
investigating central vein stenosis (24). It is important to
know that their absence cannot exclude obstruction. Additional efforts have been made to determine criteria for
investigation of obstructed iliocaval venous stents. PSVs
are likely higher inside a stented vein versus a nonstented
healthy vein due to changes in the elastic properties of the
vein (25). Nonetheless, initial efforts to establish criteria
for stented iliac veins showed that a PSV >10cm/s and
a ow pattern with spontaneous respiratory variability
ruled out venous stent obstruction with a specicity of
93.7% (95% condence interval [CI]: 86.0%–97.3%).
APSV <10cm/s or any Doppler ow pattern other than
spontaneously modulated by respiration was 92.1% (95%
CI: 79.2%–97.3%) sensitive for detection of venous stent
obstruction (23). Additional characteristics must still be
studied for the development of more accurate criteria (25).
The four components that should be examined in
all venous duplex examinations are visualization, compressibility, ow, and augmentation. There are ways to
potentially distinguish acute obstruction from chronic
obstruction (Table12.1). The veins with acute thrombosis are echolucent, are distended, and have smooth walls.
In chronic thrombosis, the veins are echogenic, are contracted, and have thick, irregular walls (Figure12.1). Acute
thrombus is “spongy” on compression examination but
will keep the walls of the vein from coapting with probe
compression. On the color ow examination, acute thrombus will have conuent ow channels. Chronic thrombus
will either have multiple channels or collateralization.
Intraluminal webs and wall thickening, with or without
reux, indicate sequelae from a previous thrombosis in the
absence of visible thrombus. The presence of dilated collateral veins indicates an ongoing compensatory mechanism
due to outow obstruction and venous hypertension, but
unfortunately, their absence cannot exclude it. It is also
possible for the veins to be fully recanalized without any
evidence of anatomic obstruction. However, the thickening
and increased stiffness of the vein wall can still result in
functional obstruction.
Signs and symptoms in both lower extremities are present when there is bilateral iliac vein obstruction or when the
IVC is involved. The iliac veins and IVC may have extrinsic
compression from masses such as tumors, enlarged adjacent organs, or retroperitoneal brosis (Figure12.2). The
extrinsic compression can lead to signs and symptoms of
CVD. In such patients, thrombosis of the compressed vein
is a common event, leading to sudden worsening of symptoms in that extremity.
12
TABLE 12.1 Duplex ultrasound criteria used to differentiate acute versus chronic obstruction
Criterion Acute (days to weeks) Subacute (weeks to months) Chronic (months to years)
Size Distended No longer distended Reduced; sometimes unable to
Echogenicity Echolucent or mixed echogenicity
Wall characteristics Somewhat thicker and smooth Thickened Thickened with luminal reduction
Flow characteristics Absence of ow/llings defects Partial recanalization Partial recanalization with reux;
Thrombus characteristic May have a spongy feel on com-
Collateral veins Absent May be present Often found around the obstruct-
with smooth borders
pression
More echogenic with some
retraction and irregular borders
It is more rm and harder to
compress
be traced by duplex ultrasound
Mostly echogenic with irregular
borders
enhanced ow in dilated collateral
veins
Less luminal material being not
compressible
ed segments
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W : 4.0 MHz
12.1 (a) Acute thrombosis in the common femoral vein. There is an absence of color, and the vein is dilated (twice the size of the
adjacent common femoral artery in red) with a homogeneous echolucent texture. (b) Acute on chronic thrombosis in the soleal
vein in a patient with recent calf pain. The vein is dilated and has echogenic material (old thrombus) and echolucent material (fresh
thrombus).
old thrombus that appears as an echogenic band in the lumen. (d) Complete recanalization with prolonged reux in the popliteal
vein. Thickening is seen in the far wall. (e) Chronic iliofemoral occlusion with collaterals from the inferior epigastric and internal iliac
veins. (f) Chronic IVC obstruction with partial recanalization. The lumen of the IVC is smaller than the adjacent aorta. The azygos
vein is dilated and larger than the aorta. (g) Nonphasic ow in a groin collateral in a patient with iliofemoral occlusion. (h) Chronic
occlusion of the external iliac vein in a female patient who underwent stenting for previous thrombosis. Flow is seen in the adjacent
artery. The vein has a small diameter and echogenic material in the lumen. The stent is seen in both the near and the far wall as an
echogenic rim between the wall and the thrombus.
(c) Chronic thrombus with partial recanalization in the great saphenous vein. Flow channels with reux are seen over the
12.2 (a) Bilateral swelling in a patient with inferior vena cava
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(IVC) compression. Note the pitting edema in both limbs after
digital compression over the tibia. (b) Compression of the IVC
by a tumor at the level of the liver. The lumen of the IVC at the
site of compression measured 0.4mm, whereas the normal distal segment measured 1.4mm. The color changes from blue in
the normal portion of the IVC to white at the area of compression indicating occurrence of the aliasing artifact due to high
velocities resulting from signicant underlying vein stenosis.
12.4 REFLUX
Venous reux is the reversal of ow in the veins of the
lower extremity. The reversal of ow in the vein can be
subdivided into physiologic and pathologic. Physiologic
reversal of ow accounts for the fraction of the second it
takes for the valve leaets to oppose. Aprospective study
has demonstrated that the acceptable physiologic reversal of ow is different for various venous systems in the
lower limb. (6) The cut-off value for reux, according to
the 2022 SVS, AVF, and AVLS guidelines, in the common
femoral, femoral, and popliteal veins is >1000 ms. For the
supercial, deep femoral, deep calf axial, muscular veins,
and perforating veins, the value is 500 ms (26). It is postulated that in the larger veins with fewer valves, the time
it takes for the valve leaets to come together is longer in
12.5 Technique 119
comparison to smaller, shorter veins. One multicenter prospective study determined that a reux of ≥0.5 seconds is
accepted as abnormal (27). Different patterns of reux are
displayed in Figure12.3.
It is important to differentiate between primary, secondary, and congenital reux. This classication is based
on the pathophysiology of the reux. Congenital reux
exists at birth, most often due to valvular agenesis or malformation, but is rarely recognized early, since there is a
lag in the presenting signs and symptoms (1). Secondary
reux is most often the result of thrombosis. The most
common type of reux is primary, where the cause has not
been determined. Astudy that has used the CEAP classication to investigate the causes of CVD showed that congenital reux accounts for 1%–3% of CVD, secondary
reux accounts for 18%–28% of CVD, and primary reux
accounts for 64%–79% of CVD (28).
12.5 TECHNIQUE
Reux can be elicited in two ways. During the Valsalva
maneuver, the intra-abdominal pressure is increased, and
this can lead to reversal of ow if there is valvular incompetence. This technique is mainly useful in the evaluation
of valves in the groin, as competent valves proximally will
limit its usefulness (26).
Compression and release distal to the point of examination on the limb is a reliable method of evaluating
reux and is referred to as augmentation (21). With compression there is an initial increase in venous return, and
therefore ow, as the blood is pushed in the normal direction of ow from distal to proximal. Once the pressure
is released, the blood ow reverses momentarily. If there
are competent valves, there is minimal to no back ow.
However, with incompetent valves, the blood continues to
ow in the reverse direction, frequently into a collateral or
perforating vein, which will dilate over time. For the purposes of more precise measurement and standardization,
the use of automated pneumatic cuffs with rapid ination
and deation is advocated for. The cuff is placed around
the leg 5cm below the probe site. A24-cm cuff is used
around the thigh, a 12-cm cuff around the calf, and a 7-cm
cuff around the foot. The ination lasts for 3 seconds followed by rapid deation in 0.3 seconds. To ensure complete venous emptying and to overcome the hydrostatic
pressures from above, thigh cuffs are inated to 80 mmHg,
those on the calf to 100 mmHg, and 120 mmHg is required
for foot cuffs. Occasionally in patients with signicant
edema, these techniques are inadequate and dorsiexion/
plantar exion is also used.
To obtain the best results, the examination should start
with the patient in the standing position, with the weight
of the patient on the contralateral limb (21). The limb of
interest should be slightly exed and externally rotated. If
a patient is unable to stand for the time required, the veins
from the mid-thigh and below can be assessed in the sitting
position. If the test is performed on a bed, the torso should
be elevated to >45 degrees. Atilt-table with a leg rest to
keep weight on the contralateral limb and reected backwards into a 60-degree position is another technique that
can be used for reux measurements.
12
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12.3 (a) Normal saphenofemoral junction. During distal augmentation there is ow towards the heart (negative deection as blood
traveling away from the transducer). After release of the compression there is a short duration of retrograde ow until the valve is
closed. (b) Prolonged reux in the great saphenous vein (GSV) below the knee. The vein has a normal diameter indicating that a
vein does not have to be dilated when it is incompetent. This patient had asymptomatic CEAP class 2 disease. (c) Reux in the
popliteal, medial gastrocnemius, and small saphenous vein (SSV). This patient had a chronic thrombosis that was fully recanalized.
He presented with CEAP class 4 and had pain and itching. (d) Reux in a lower calf medial perforator in a patient with a healed ulcer
(C5). The vein was dilated (>6mm) and had prolonged outward ow. (e) Cross-sectional view of a focal dilation in the lower thigh
GSV with a frozen valve seen at the 4 o’clock position.
skin changes, edema, and varicose veins in the posterior calf. The diameter of the SSV measured 8mm and the reux duration was
longer than 5 seconds. (g) Prolonged reux from the medial gastrocnemius vein (GV) to the SSV. The SSV was incompetent from its
junction with the gastrocnemius vein at mid-calf to the lateral malleolus. The proximal SSV was normal.
The routine examination of the veins of the lower
extremity starts at the common femoral vein above the
junction of the femoral and deep femoral veins. The SFJ at
the terminal and preterminal valve and the associated tributaries are examined next. This is followed by the popliteal
and deep calf veins. The GSV, SSV, accessory saphenous,
their tributaries, large perforators, and nonsaphenous veins
(f) Dilation of the SSV in the upper calf with wall thickening in a patient with
are examined in detail, as these are the most common sites
of reux. Reux in veins that are not part of the GSV or
SSV system are found in about 10% of patients (29). Veins
of interest involved in nonsaphenous vein reux are the
gluteal vein, posterolateral thigh PV, vulvar vein, lower
posterior thigh vein, popliteal fossa vein, knee perforator
vein, and sciatic nerve vein (30). The GSV can be identied
12.5 Technique 121
N
N
LT
partial recanalization with reux
C1–3A EP AS+P PR C1–4S EP AS+P+D PR+O
N
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and distinguished from other supercial veins because it
is surrounded by two layers of fascia in a conformation
called the saphenous eye, in reference to the eye of Horus
(31). The SSV is found in the triangular fascia and is surrounded by the crural fascia and the medial and lateral
heads of the gastrocnemius muscle (32). The tributaries of
the supercial veins that are often incompetent in the thigh
are the anterior and medial accessory veins, and in the
calf, they are the posterior and anterior arch veins. These
veins should be examined along their full length if they are
incompetent to document the extent of reux and the location where it begins and drains into.
Duplication of the saphenous veins is rare, reecting <3% of patients with CVD (32). The most common
anatomic variations of the saphenous veins are segmental
hypoplasia, aplasia, and subdermal trajectory, wherein the
vein is found outside of the fascial envelope and is close to
the skin (33). Accessory veins ensuring good venous drainage are frequently found close to such segments (33).
PVs are the last to be examined. They can be distinguished
from the supercial and deep veins since they course perpendicular to these veins and pierce the deep fascia. The deep
fascia is dense and echogenic and can be easily visualized
on an ultrasound scan. There are approximately 150 PVs in
the lower extremity, of which only 20 are of clinical significance in terms of reux possibly leading to clinical pathology (34). The normal direction of ow is from the supercial
to the deep veins through the PVs. These veins are examined using transverse and oblique scanning, since their long
axes are seen in these planes. They are found by following
the course of the GSV, the SSV, and the tributaries. Outward
ow in these veins is seen only in the presence of supercial and deep vein reux. Based on the current Society for
Vascular Surgery and American Venous Forum guidelines for
the care of patients with CVD, duplex scanning of the PVs
should be performed selectively (2, 26). PVs are deemed to
be “pathologic” when an outward ow of duration of ≥500
ms, a diameter of ≥3.5mm, and a location beneath healed
or open venous ulcers (CEAP class C5–C6) are present (2,
26). These guidelines aid physicians in making their decisions
on whether PVs need to be treated (2, 26). Special attention
should be given to perforating veins that are abnormally tortuous, as this can be a sign of underlying pathological reux.
The results of an ultrasound examination in patients
with CVD are often depicted in drawings to facilitate the
comprehension of ndings and to summarize pathology.
An example of this is given in Figure12.4. The left and
right lower extremities have been drawn to scale and have
12
Right
R
R
R
N
R
R
Left
R
R
R
R
R
R
R
R
12.4 Report of a duplex ultrasound examination in a patient with bilateral chronic venous disease (CVD). She was a 53-year-old
female with two pregnancies and a positive family history of CVD in both parents. She noticed signs and symptoms of CVD after
her second pregnancy, rst in the left lower extremity and 2years later in the right lower extremity. She had also developed thrombosis in the left lower extremity 7years previously. LT, left; MGV, medial gastrocnemius veins; N, no reux; POPV, popliteal vein;
and R, reux.
: POPV + MGV
122 Chapter 12 DUS scanning for chronic venous obstruction and valvular incompetence
Class 0
1.3
Percentage (%)
0
Primary + secondary
Reux + obstructio
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skin, muscular, and bony landmarks such as the popliteal
skin crease, sartorius muscle, knee, and medial malleolus.
Such drawings enable better understanding and interpretation of the ndings and therefore facilitate the planning of
treatment in each limb and may have different standardizations depending on local protocol. Reux is often represented in red throughout the venous segment.
12.6 ROLE OF DUS IN UNDERSTANDING
THE PATHOPHYSIOLOGY OF CVD
The majority (70%–80%) of patients presenting with CVD
are symptomatic. These symptoms include itching, ache,
restless limb, heaviness, burning, and ulceration. Varicose
veins and telangiectasias are present in 80% of patients.
Skin changes of some sort are seen in 20%–25%, and
active or healed ulcerations in 12%–14% of patients with
CVD (Figure12.5). Patients with C1 and C2 disease have
reux conned to the supercial system. As the clinical
severity worsens (C3–C6), the prevalence of incompetence
in the perforator and deep veins increases. In limbs with
CVD, reux alone exists in 80% of patients, reux and
obstruction are present in 17% of patients, and only 2% of
patients have obstruction alone (28). In addition, the combination of reux and obstruction has a worse prognosis
for the development of skin lesions (11, 29, 35, 36).
The most common location of reux in patients with
CVD is the saphenous vein trunks and their tributaries,
irrespective of clinical class. These veins are affected in 90%
of patients. Of the supercial veins, the GSV is involved
in 70%–80% of cases, the SSV is involved in 15%–20%,
and nonsaphenous veins are involved in about 10%. The
deep system is only affected in 30% of patients with CVD,
and the PVs in 20%. (9) Complex patterns of reux are
present in patients with skin damage (36). Several studies have demonstrated that reux in the supercial system
alone is the cause of 17%–54% of venous ulcerations. Of
all limbs with venous ulceration, 74%–93% have reux in
the supercial system (29, 37, 38). Supercial reux, with
or without perforator reux, is present in more than 50%
of patients with ulceration (36). This subclass of patients
will benet from intervention directed towards the supercial venous system (39). Isolated deep vein reux occurs
in <10% of patients (36, 38–40). Among the deep veins,
popliteal vein reux has the strongest association with the
severity of CVD. Two vein systems are involved in ulcerated limbs in 52%–70% of patients, and all three systems
are involved in 16%–50% of patients (38–40). The veins
that are in the ulcer bed or within 2cm of the ulcer have
reux in 86% of cases. However, perforator vein reux is
found only in a third of cases in this area (38). Saphenous
reux can occur without SFJ and saphenopopliteal junction (SPJ) incompetence; therefore, ligation of these junctions may not be appropriate in such patients (35, 41). In
2.6%–4.0% of patients, no reux or obstruction is found
in any of the systems. In these patients, other causes of
ulceration should be evaluated (42).
It has been shown that saphenous hypoplasia occurs in
varicose limbs more frequently than in healthy ones (P <
0.001). It greatly inuences the path of the reux and the
anatomy of the varicose veins. GSV segmental hypoplasia
can be detected preoperatively by duplex ultrasonography. Its occurrence may inuence surgical management for
two main reasons: in about 68% of varicose limbs with
segmental hypoplasia, the distal GSV is competent; if the
distal GSV is incompetent, its size and ow direction are
normalized by treating the accessory vein that bypasses the
hypoplastic segment (33).
Several patterns of reux in the supercial veins are
worthy of discussion, as treatment of the saphenous trunks
may be avoided. In fact, there are occasions where both the
GSV and SSV should be spared. An incompetent anterior
accessory vein with or without involvement of the SFJ in
the absence of GSV reux is found in 9% of patients. After
treating the anterior accessory vein, at 1-year follow-up,
no patients had reux in the GSV and 95% were satised
with the treatment. In a large series of patients with reux
in the SSV system, 3.1% had incompetence in the thigh
extension of the SSV only (32). In another series where the
thigh extension was studied, in the GSV and SSV system,
reux was found in 4.7% (43). Reux in the tributaries
alone was detected in 9.7% of limbs with CVD. The most
common site was the posterior arch vein (44).
12.5 Presentation of 1000 consecutive limbs with chronic venous disease according to the CEAP classication.
Class 1
Class 2
Class 3
Class 4
Class 5
Class 6
Primary
Secondary
Congenital
Supercial
Perforating
Deep
Reux
Obstruction
n
5.9
20.4
16.7
21.6
24.7
24.2
28.8
4.3
8.2
6.1
0.9
1.8
010203040
38.3
68.3
90.7
81.6
50 60 70 80 90 10
12.6 Role of DUS in understanding the pathophysiology of CVD 123
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12.6 Examples of reux in nonsaphenous veins. (a) Varicose tributaries are seen in the right popliteal fossa of a male patient who
presented with pain and itching. The varicosities disappear above the popliteal skin crease as they dive deeper to join the popliteal
vein. (b) Signicant reux in the vein of the popliteal fossa of the same patient. The vein is dilated and varicose and pierces the deep
fascia just above the popliteal skin crease. It unites with the lateral aspect of the popliteal vein above the saphenopopliteal junction.
(c) Reux in the dilated and tortuous veins of vastus medialis muscle. These veins were connected to a perforating vein at the lower
thigh that was in continuity with posteromedial varicose tributaries. (d) Left ovarian vein reux in a 24-year-old woman with three
pregnancies. She presented with left vulvar veins that were extending from the groin medial to the GSV to the posterolateral calf. The
ovarian vein measured 8.8mm in diameter.
12
Reux in nonsaphenous veins, such as those of the vulvar, gluteal, posterolateral thigh, and other locations, is
found in 10% of limbs with CVD. (10) These are mostly
multiparous female patients with a mean of three pregnancies. On all of these occasions, treatment can be targeted
by ultrasound and the saphenous veins spared. Reux in
nonsaphenous veins is seen in Figure12.6.
It has been suggested that in patients with primary reux
in the supercial and deep system, deep venous reux may
be directly linked to supercial reux. The reux circuit
theory of venous overload states that reux in the supercial system at the level of the perforators and major supercial to deep vein junctions will ow into the deep system
and overload the deep system. This leads to dilatation and
the development of reux in the deep system. It has been
demonstrated that by surgically correcting the reux in the
supercial system, the deep system reux is also eliminated
in more than 90% of patients (45). In a prospective study,
deep reux in patients with primary CVD was shown to
occur near the SFJ, SPJ, and gastropopliteal junction (46). It
was more likely to occur when the reux at these junctions
had high peak velocity and long duration. The reux in the
deep veins was usually segmental and of shorter duration
than post-thrombotic reux. Arecent study of 30 limbs has
demonstrated that signicant hemodynamic compromise is
present when deep vein reux is caused by supercial vein
reux only when the popliteal vein valves are incompetent
(47). Additionally, reux has more recently been linked
to proximal outow obstruction. Arecent study of 1228
patients that had undergone iliac vein stenting has shown
that reux resolution after stenting varied from 21% in the
femoral vein segment to 58% at the perforating veins, with
complete reux resolution in 23% of all limbs. Additionally, in this population, new-onset reux was shown to be
rare, with a median incidence of 7% (48). Iliac vein stenting has also been shown to reduce compartment pressures
in the extremity treated (49).
Most PVs have at least one subfascial bicuspid valve
that prevents reux from the deep system to the supercial
system. The role of PV incompetence in the development
of the signs and symptoms of CVD remains unclear (50).
However, there is evidence to suggest that the number of
incompetent PVs and the sizes of competent and incompetent PVs increase with worsening CVD (34, 50, 51). It has
also been reported that patients with increasing numbers
of incompetent PVs have a higher venous lling index. The
venous lling index is known to correlate well with the
severity of CVD (51). PV incompetence occurs more in the
calf than in the thigh (29, 34, 51). More incompetent PVs
are found in the lower and middle thirds of the medial calf.
Most PVs that are >3.5mm in diameter will be incompetent (34). However, the sensitivity of size alone determining incompetence is low, as about a third of the reuxing
PVs have a diameter of <3.5mm. The duration of outward
ow and local hemodynamics worsen in PVs when both
the supercial and deep veins connected to those PVs are
incompetent (34, 43). The development of new PV reux
is closely related to reux in the supercial system. In
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