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184
Chapter 3 · Extremity Veins
B-mode ultrasonography is the most suitable imaging
modality both to identify the upper end of the thrombus for
the initiation of adequate therapeutic management and to
follow up therapy.
A retrospective analysis of the ultrasound ndings in
3
363 patients with thrombophlebitis demonstrated growth of
the thrombus into the deep venous system over an observation period of 10days in 11% of the cases. Seventy percent
of these cases were accounted for by great saphenous vein
thrombophlebitis with thrombus growth into the common
femoral vein (Foley etal. 1989).
Other ultrasound studies of thrombophlebitis show
thrombotic involvement of the deep venous system in
11–44% of patients, which is a much higher rate than suspected on the basis of the clinical appearance (Blättler 1993;
Blättler etal. 1996; Gaitini 1990; Gaitini etal. 1988; Lutter
et al. 1991; Jorgensen etal. 1993; Ascer et al. 1995). Since
therapeutic management must encompass the deep veins in
these patients, the indication for ultrasonography of the deep
leg veins should be established generously.
In patients presenting with chronic venous insuciency,
the question to be answered is whether the condition is due
to great or small saphenous vein varicosis or whether it
exists in the context of the postthrombotic syndrome. As the
therapeutic consequences are dierent, adequate diagnostic
workup always includes evaluation of the morphologic and
functional status of the major deep veins. Primary valve
incompetence of the supercial veins (varicosis) without
involvement of the deep veins is treated by surgical removal
of the aected supercial vein segments to prevent dermatologic damage as well as secondary involvement of the
deep leg veins due to pressure and volume overload (socalled Trendelenburg private circulation; Hach and HachWunderle 1994). In secondary valve incompetence of the
supercial veins with simultaneous deep vein involvement
(postthrombotic), on the other hand, excision of the varices
will not provide much improvement with regard to venous
return. With few exceptions, surgery is not indicated in this
situation. Instead, patients, including those operated on, are
treated by a rigorous compression regimen (which must also
be continued aer surgery).
Incomplete recanalization or nearly complete postthrombotic occlusion
the surgical removal of incompetent supercial vein segments.
Tailoring therapeutic procedures to the individual patient
relies on precise information regarding the localization and
extent of morphologic and hemodynamic abnormalities.
Duplex ultrasound is superior to all other imaging modalities in providing this information. To obtain all relevant diagnostic information in patients with varicosis, the ultrasound
examination should include the following components:
5 Evaluation of major supercial veins (great and small
saphenous veins), terminations, recirculation pathways
(truncal insuciency)
5 In patients with incomplete truncal varicosis:
5 Determination of the upper point of insuciency
5 Determination of the lower point of insuciency
of deep veins is a contraindication to
5 Identication of incompetent perforating veins
5 Demonstration of secondary major vein insuciency/
valve incompetence of major deep veins
5 Identication of variant terminations of supercial veins.
Morphologic variants
5 Detection of (residual) thrombus in the supercial and
deep venous systems
5 Quantication of poor venous return
If sclerotherapy is planned for the treatment of varicosis of
a side branch or mild truncal varicosis, ultrasound can also
serve to guide insertion of the thin cannula for injection of
the sclerosing agent, particularly in obese patients, and to
assess outcome.
3.1.6 Duplex Ultrasound: Diagnostic
Criteria, Indications, andRole
3.1.6.1 Thrombosis
e most important sonographic criterion of acute deep or
supercial vein thrombosis is incompressibility of the vein
when applying pressure with the transducer in transverse
orientation (. Figs.3.17, 3.18, 3.19, and 3.21).
Additional sonographic ndings supporting the diagno-
sis of acute deep vein thrombosis (DVT) are:
5 Widening of the lumen (other than breathing-related
diameter variation)
5 Abnormal intraluminal structure of low echogenicity
(but more echogenic than owing blood), may appear
inhomogeneous
5 Absence of extravascular causes (perivascular structures)
of disturbed venous drainage
A fully compressed vein is no longer visible. Only a highresolution transducer will depict the thin venous wall as an
echogenic line within the muscle tissue. Incomplete compressibility indicates a thrombus surrounded by owing
blood (adherent to wall, oating) or partial recanalization
aer thrombosis with residual thrombus or severe wall sclerosis preventing full compression (
e examination is usually performed with the patient
lying on the examination table. Having the patient sit or
stand may augment blood ow and improve evaluation of
the calf veins. In the calf, the presence of a fresh thrombus
improves visualization because the hypoechoic dilated vein
is more conspicuous than a collapsed vein or a small, thinwalled vein with normal blood ow. A positive compression
ultrasound result is nearly 100% specic for DVT of the
leg. A negative result can rule out thrombosis in the thigh
and in the popliteal fossa with acceptable accuracy. Some
uncertainty remains in below-knee thrombosis, even with
additional use of color Doppler imaging. If the ndings are
equivocal and the clinical presentation is highly indicative of
thrombosis (high pretest likelihood), additional diagnostic
tests should be performed including venography, a -dimer
test or repeat ultrasound aer 5days.
. Figs.3.18 and 3.19).
c
VV
3.1 · Pelvic andLeg Veins
a
185
TransducerTransducerTransducer
3
AA
V
b
. Fig. 3.17 a Normal compression ultrasound of the popliteal vein (transducer in popliteal fossa): the vein and artery have similar diameters,
and the walls are clearly delineated from surrounding fatty connective tissue (left gray-scale image). Applying pressure with the transducer
(right gray-scale image) results in complete compression of the popliteal vein (<V.POP)– the lumen is no longer visible and the delicate walls
are just barely distinct from the surrounding tissue. In the color ow image (right), ow in the popliteal artery is encoded in red (A). In the popliteal vein, the main ow direction is encoded in blue (V). There is also some ow in the opposite direction (coded in red) from venous branches
joining the popliteal vein at these sites. b Diagram of compression ultrasound. A patent vein is completely compressible and virtually disappears when pressure is exerted with the transducer (second drawing). A thrombosed vein retains its shape upon compression (right drawing),
while a partially thrombosed or partially recanalized vein can be compressed to some degree. A very fresh thrombus in a large vein may also
be compressible to some extent, while the vein itself often has a wider lumen than the unaected vein or the accompanying artery. A more or
less hyperechoic intraluminal structure may be visualized (see . Fig.3.25). c Acute thrombosis of the popliteal vein. The fresh thrombus markedly dilates the lumen of the vein (V.POP) (up to twice the size of the adjacent artery). The predominantly low echogenicity of the lumen clearly
dierentiates the vein from surrounding fatty connective tissue. Application of pressure with the transducer (right gray-scale image) results in
attening of the thrombus, while the vein itself retains its shape. The color ow image (right; low PRF to detect slow ow) shows no ow in the
popliteal vein (V) except for some residual marginal ow (blue). This nding corresponds to the rubber phenomenon in venography (Modied
from Schäberle 2014)
A
186
c d
Chapter 3 · Extremity Veins
Transducer Transducer
3
AA
V
a b
. Fig. 3.18 a Compression ultrasound ndings in partially thrombosed veins. When pressure is applied to a vein containing a mural thrombus sur-
rounded by owing blood (right drawing), only the patent portion of the lumen is compressible. The delineation of the thrombus within the lumen
depends on its echogenicity, which in turn is determined by its composition. b B-mode imaging of the femoral vein without compression (left) and
with compression (right). Incomplete compressibility of the vein (V.F.) is due to thrombus (T) in the center of the lumen. The thrombus is identied
by its higher echogenicity compared with owing blood. c Gray- scale and color ow images showing oating thrombus (T) extending from the great
saphenous vein (V.S.M) into the femoral vein (V.F.C). This thrombus prevents full compression of the vein. d Venogram conrming the thrombus
V
Incompressibility is a necessary and sucient criterion
for the diagnosis of DVT of the leg. Study results indicate
that color duplex imaging does not improve diagnostic
accuracy in DVT and tends to be less specic when used
alone (i.e., without compression) because slow venous ow
or poor imaging conditions below the knee may give rise to
false positive ndings. Color duplex is required only to diag-
Transducer
Transducer
nose isolated pelvic thrombosis, which is rare. Evaluation
of ow in the color duplex mode improves the diagnostic
evaluation at the pelvic level, especially in obese patients,
in whom compression maneuvers are dicult to perform.
Moreover, color duplex imaging enables identication of
residual blood ow around a thrombus or oating throm-
A
V
A
V
bus and also of recanalized veins, which oen have a small
lumen (see . Fig.3.23).
Isolated pelvic vein thrombosis is thus the only case
in which compression ultrasound alone tends to be unreliable due to the lack of an adequate structure against which
to compress the vein and interfering overlying structures.
. Fig. 3.19 Compression ultrasound of a partially recanalized vein.
The extent to which the vein can be compressed depends on the
degree of recanalization. Residual mural thrombi prevent full compression (. Fig.3.23)
Instead, the diagnosis is based on absent or abnormal ow
(compared to the unaected side) in the Doppler waveform
or a gap in color lling in the color duplex mode.
3.1 · Pelvic andLeg Veins
187
3
. Fig. 3.20 Compression ultrasound ndings in dierent calf veins. a Isolated soleus vein thrombosis (<V>) with widening of the aected seg-
ment. The lumen is hypoechoic and incompressible (right image). The posterior tibial vein (V TIB P) and bular vein (V FIB) are patent (left image)
and compressible (right image). Color duplex imaging can help the examiner in identifying the main calf veins by rst looking for the corresponding arteries, and the evaluation of ow can corroborate the diagnosis made by compression ultrasound. (The images shown are not magnied to
illustrate what the examiner will see in the routine clinical situation.) b In this example, both branches of the paired bular vein (V) coursing to the
left and right of the artery of the same name, are widely dilated and cannot be compressed (middle image, obtained while applying pressure with
the transducer). The diameter is more than twice that of the artery (A), consistent with fresh thrombosis. The intraluminal thrombotic material has
low echogenicity and appears homogeneous. The longitudinal color ow image (right) shows no ow in the vein (see . Fig.3.56 (Atlas)), and
there is thrombosis at the site of a valve cusp (VK>). c Isolated thrombosis of one branch of the paired bular vein. The thrombosed branch does
not collapse (V FIB) when pressure is exerted with the transducer (KOMP, center image), and there is no spontaneous ow in this branch in the
color duplex image (left). The shrunken lumen and poor demarcation from surrounding muscle tissue (right image) are signs of older thrombosis.
The posterior tibial vein (KOMP, middle image) is compressible, and there is good color lling upon slight manual compression of the calf distal to
the transducer (right part of leftmost image) (see . Fig.3.51 (Atlas))
Careful scrutiny of the pelvic axis is indicated if an abnor-
mal Doppler waveform
with reduced respiratory phasicity
and slower ow compared to the contralateral side is obtained
in the distal external iliac vein. e patient must lie supine
with the thigh slightly abducted and externally rotated to
ensure undisturbed venous outow under the inguinal ligament. Flat positioning with the thigh stretched will compress
the vein as it courses under the inguinal ligament, reducing or
even eliminating respiratory phasicity in the Doppler waveform obtained from this site. However, since even isolated
pelvic vein thrombosis typically involves the entire external
iliac vein (including drainage through veins of the saphenofemoral junction and abdominal wall), the thrombosis can be
demonstrated by B-mode and compression ultrasound above
the inguinal ligament. is method of indirect hemodynamic
ow analysis in the groin will only miss non- ow- obstructing
thrombus (i.e., thrombus extending from the external iliac
into the common iliac vein or thrombosis caused by mural
thrombi in a partially patent pelvic vein).
e small-caliber vessels below the knee are less well
demarcated from the inhomogeneous echotexture of
surrounding muscle tissue. Still, the criteria for isolated vein
thrombosis
in this territory are the same as in the thigh.
Better lling of the veins is achieved if the examination
is performed in the sitting or standing patient. Since a tubular structure distended by acute thrombosis can be identied more easily than a normal vein, nonvisualization can be
interpreted to indicate absence of acute thrombosis. Note,
however, that this only holds true for acute venous thrombosis, whereas older thrombi shrink and oen become more
hyperechoic and inhomogeneous with the venous lumen
returning to its normal diameter. Hence, the vein is again
more dicult to dierentiate from surrounding muscle tissue (. Figs.3.20, 3.50 (Atlas), 3.51 (Atlas), and 3.52 (Atlas)),
rendering the method less accurate in identifying older
thrombosis below the knee.
Many studies with dierent study designs conducted in
the 1980s and 1990s yielded sensitivities of 88–100% and
specicities of >95% for compression ultrasound compared
with the then gold standard, venography (. Table 3.2). A
meta-analysis (with subgroup analysis by site of thrombosis) found >95% sensitivity for the femoropopliteal segment
188
Chapter 3 · Extremity Veins
. Table 3.2 Studies investigating the diagnostic performance of compression ultrasound, duplex ultrasound, and color duplex
ultrasound in larger patient populations with suspected deep vein thrombosis (DVT) of the leg (with venography as the gold standard)
Author/Year Patients [n] Thrombosis [n] Sensitivity [%] Specicity [%]
Compression ultrasound
3
Appelman etal. (1987) 112 52 96 97
Dauzat etal. (1986)
Elias etal. (1987)
a
a
Habscheid etal. (1990)
b
145 100 94 100
430 303 98 95
238 153 96 99
Hobson (1990) 209 – 99 100
Krings etal. (1990) 182 – 95 97
Lensing etal. (1989)
b
220 66 99 100
Pederson (1991) 215 113 89 97
Herzog etal. (1991)
b
113 57 88 98
Langholz (1991) 64 25 76 88
Compression ultrasound: analysis of below-knee veins only (thrombosis)
b
Habscheid (1990) 37 – 89 99
Elias etal. (1987) 92 – 91 96
Duplex ultrasound
De Valois etal. (1990) 180 61 92 90
Comerota etal. (1990) 103 44 96 93
Killewich etal. (1989)
b
47 38 92 92
Van Ramshorst etal. (1991) 117 64 91 95
Schäberle (1991)
b,c
125 56 97 98
Betzl (1990) 66 – 97 72
Color duplex ultrasound
Schindler etal. (1990) 97 54 98 100
Grosser etal. (1990)
b
180 154 94 99
Van Ramshorst etal. (1991) 117 64 91 95
Schönhofer (1992) 100 63 97 98
Miller etal. (1996) 216 98 99 100
Fürst etal. (1990) 102 39 95 99
Persson etal. (1989)
Rose etal. (1990)
b
b
264 16 100 100
69 32 79 88
Van Gemmeren etal. (1991) 114 74 96 97
Langholz (1991) 116 65 100 94
Fobbe etal. (1989) 103 58 96 97
Lensing etal. (1989) 220 – 91 99
Krings etal. (1990) 235 – 93 96
Schweizer etal. (1993)
78 70 96 100
(with ultrasound contrast agent)
Note that below-knee veins were not included in the examination in all cases
a
Compression ultrasound, in part, supplemented by CW Doppler
b
Below-knee veins included in examination and analysis
c
Compression ultrasound as rst-line diagnostic test with optional supplementary duplex ultrasound (primarily to assess pelvic veins and
resolve inconclusive ndings below the knee)
3.1 · Pelvic andLeg Veins
189
3
and 85–90% sensitivity for veins below the knee (Elias etal.
1987; Lensing etal. 1989; Krings etal. 1990; Atri etal. 1996;
Habscheid 1990 and 1998; Schäberle 2010). Of note are the
studies of Habscheid and Elias et al. because they determined sensitivity and specicity separately for veins below
and above the knee. Habscheid (1990) found 88% sensitivity
below the knee versus 96% above the knee with 99% specicity for both territories. Elias etal. (1987) found 91% versus
98% sensitivity. ese studies have also revealed that venography is a poor gold standard, especially below the knee,
where nonvisualization of a vein such as the bular vein is
inconclusive, suggesting either thrombosis or a technical
limitation of the method (nonopacication) (. Figs.3.55 and
3.56 (both Atlas)).
In addition to the major veins below the knee (which can
be identied using the arteries of the same name as landmarks), the muscle veins of the gastrocnemius and soleus
groups
deserve special attention. ey are a common source
of DVT, especially in immobilized patients. Stasis of blood
ow is common when the muscle veins become ectatic with
age. e diagnostic criteria are the same as for thrombosis
of the main veins (dilated, incompressible vein, identied
as a tubular structure in its typical location in the muscle).
rombosis of muscle veins below the knee and of the deep
femoral vein is rarely detected by venography.
e diagnostic limitations of venography (see
3.1.9
) in the evaluation not only of below-knee veins, such as
the bular vein and muscle veins, but also of supercial leg
veins led some investigators to abandon venography as the
gold standard. Instead, they determined the occurrence of
thromboembolic complications in untreated patients (typically at 3-month follow-up) as a measure of the diagnostic
performance of ultrasound
ultrasound in terms of missed thrombosis rather than in
comparison to venographic ndings. A meta-analysis of 7
studies found a pooled venous thromboembolism event rate
of 0.57% (0.25–0.89%) in a total of 4731 patients who did not
receive anticoagulation aer negative whole-leg compression
ultrasound (Johnson etal. 2010). ese studies also revealed
a dierence between outpatients and inpatients (higher prevalence).
In most patients, femoropopliteal thrombosis is due
to ascending thrombosis arising in a main vein below the
knee or a muscle vein. Surprisingly, a review of therapeutic
studies including a total of more than 3500 patients with
suspected thrombosis in whom only the territory from the
distal external iliac vein (inguinal ligament) to the distal
popliteal vein was continuously evaluated using compression ultrasound identied a 3-month thromboembolism rate
of only 0.4–2.6% in untreated patients. While this protocol
will miss instances of isolated below-knee thrombosis, this
has no diagnostic or therapeutic relevance because the clinical course tends to be uncomplicated as long as there is no
ascending growth. Nevertheless, various diagnostic algorithms (
thromboembolic complications from ascending growth of
missed below-knee thrombosis (Bernardi etal. 1998; Cogo
. Fig.3.21) were proposed to minimize the risk of
. In other words, they assessed
7 Sect.
etal. 1998; Perrier etal. 1999; Wells etal. 1997) (
Specically, investigators used the following measures to
supplement diagnostic workup in patients with negative
ultrasound ndings but clinically suspected thrombosis
5 Repeat compression ultrasound aer 1week (Cogo etal.
1998)
5 D-dimer test for risk stratication before repeat ultra-
sound (Bernardi etal. 1998)
5 Supplementary venography in patients with a relevant
risk but negative compression ultrasound (Perrier etal.
1999)
5 Repeat compression ultrasound in patients with initially
negative compression ultrasound; venography only in
patients with a high likelihood of thrombosis based on a
set of clinical criteria (Wells etal. 1997).
All of these algorithms were proposed to remedy the diagnostic uncertainty of compression ultrasound in the calf
(85–90% sensitivity) by supplementary measures. e most
common strategies include the highly sensitive but rather
unspecic -dimer test, repeat ultrasound aer 1week, and
venography in high-risk patients (
empirical and clinical experience, patients with suspected
venous thrombosis can be assigned to a high-probability
or a low-probability group on the basis of their risk factors,
the severity of clinical signs, and the likelihood of alternative conditions that may explain their symptoms. is risk
stratication guides further diagnostic management if the
ultrasound ndings are inconclusive. For instance, highrisk patients will undergo supplementary venography or a
-dimer test, while no further diagnostic measures will be
taken in patients with a low risk (. Fig.3.21).
Some of the diagnostic algorithms proposed in the literature are rather complex. In the hands of an experienced
examiner, compression ultrasound yields clinically acceptable results despite its limitations below the knee. In a study
of 1265 patients in whom treatment decisions were made on
the basis of a complete compression ultrasound examination
of the leg veins, 0.3% of patients with negative ndings experienced a thromboembolic event during 3-month follow-up
(Schellong etal. 2003). is low risk of DVT in patients with
negative ultrasound examinations including the calf veins
was conrmed in another study, which reported thromboembolic complications in 0.5% of cases (Elias etal. 2003) (see
7 Sect. 3.1.9.1 and . Fig.3.38).
e diagnostic accuracy of ultrasound including the
veins below the knee
studies conducted more recently (Stevens et al. 2004;
Subramaniam etal. 2005; Sevestre etal. 2009; Stevens etal.
2013). e residual failure rate is less than 1%, which is at the
upper limit of the 95% condence interval. Note, however,
that cohort studies oen include many patients with a low
pretest likelihood of disease. e only study that selectively
investigated patients with a high pretest probability (n=167)
(Stevens etal. 2013) found a low thromboembolism rate of
0.6% at 3months in patients with prior negative ultrasound
above and below the knee (see 7 Sect. 3.1.9.1).
is also conrmed by large cohort
. Table 3.3). Based on
. Table3.3).
:
190
sN
--
--
Chapter 3 · Extremity Veins
Suspected thrombosis
Compression ultrasound
3
–
Suspected thrombosis
Compression ultrasound
–
D-dimer test
1
Repeat compression ultrasound
+
+
Thrombosis
Suspected thrombosis
D-dimer test
Compression ultrasound
after 1 week
–
No thrombosis
Cogo BMJ 1996:316:17
+
+
ultrasound after 1 week
+
2
Thrombosis
+
Repeat compression
–
No thrombosis
–
E Bernardi BMJ 1998:317:1037
Suspected thrombosis
Compression ultrasound
–
Clinical risk assessment
High
Moderate
Low
–
4
+
Venography
+
Repeat compression
ultrasound after 1 week
–
+
–
o thrombosis
Variant of P Wells Lancet 1997:350:1795
High risk
Low/Moderate risk
–
Venography
+
3
Thrombosis Thrombosis
–
No thrombosi
Perrier A Lancet 1999:353:190
Suspected thrombosis
Clinical criteria for predicting pretest probability of
thrombosis (according to Wells 1997)
Compression ultrasound
–
Clinical risk assessment
High
+
Moderate
D-dimer test
Low
+
Ultrasound follow-up after 1 week
(or immediate venography)
+
a
. Fig. 3.21 a Algorithms for the diagnostic management of deep vein thrombosis (DVT) of the legs. The clinical risk of DVT is assessed by means
of a scale with a score greater than 2 indicating a high risk of thrombosis and a score of 1 or 2 a moderate risk. Charts 1–4: Algorithms used in prospective studies with compression ultrasound restricted to veins above the knee including the popliteal vein. Chart 5: Diagnostic algorithm with
compression ultrasound of the veins above and below the knee and procedure in patients with inconclusive ndings below the knee (according
to W.Habscheid). No further diagnostic tests are required in patients with a moderate risk and negative ultrasonography of the calf performed by
an experienced examiner (see . Fig.3.38). b Algorithm for the diagnostic management of DVT using whole-leg compression ultrasound as the
only diagnostic test; 3-month thrombosis rate of 0.3% in the group with negative ultrasound ndings (Schellong etal. 2003)
5
Thrombosis
–
No thrombosis
–
Clinical feature
Active cancer
Leg immobilization (cast, paralysis)
Bedridden > 3 days, postoperative
Leg swelling (unilateral)
Calf swelling > 3 cm
Pain (tenderness) along distribution of veins
Dilated superficial collateral veins
Clinical findings or history of other disease
that explains symptoms or is more likely than
thrombosis
Score
1
1
1
1
1
1
1
–2
b
3.1 · Pelvic andLeg Veins
191
3
Suspected thrombosis
Compression ultrasound
including lower leg veins
Thrombosis
Treatment
. Fig. 3.21 (continued)
No thrombosis
No further diagnostic testing
e largest database was analyzed in the above-quoted
study of Johnson etal. (2010). is meta-analysis of the diagnostic accuracy of a single compression ultrasound examination for ruling out DVT included 7 studies totaling 4731
patients with negative whole-leg compression ultrasound
who did not receive anticoagulation. e rate of clinically
apparent venous thromboembolism in this population was
only 0.57% during 3-month follow-up.
Data on the outcome of thrombosis indicate that patients
with completely recanalized veins have a lower risk of recurrence than patients whose veins recanalize only incompletely
(1.3% versus 23.3%). In a group of 180 patients with residual
thrombosis aer 3months of anticoagulation (69% of the total
study population), recurrent thrombosis occurred in 19.3%
of patients who continued anticoagulation treatment and in
27.2% of patients who discontinued treatment (Siragusa etal.
2008). In the group of 78 patients (31%) without sonographic
evidence of relevant postthrombotic residues (complete
recanalization), there was only one case of recurrent thrombosis. ese results indicate that follow-up ultrasound ndings at 3 and 6months are helpful in identifying patients who
might benet from prolonged anticoagulant treatment.
Another study using serial ultrasound follow-up found
a cumulative incidence of postthrombotic states without
major postthrombotic residues in 38.8% of cases at 6months,
58.1% of cases at 12months, 69.3% at 24months, and 73.8%
at 36months (Prandoni etal. 2002 and 2009). In this population of initially 313 patients, 41 of the 58 patients with recurrent thrombosis had major postthrombotic residues (hazard
ratio of 2.4, 95% condence interval: 1.3–4.4; p = 0.004;
patients with residual thrombosis versus patients with early
recanalization).
ese ndings suggest that, in patients with sonographic
evidence of
major residual thrombosis, the risk of recurrent
thrombosis can be reduced by prolonging anticoagulation
treatment.
Recanalization aer an episode of DVT is subject to individual variation, which is why a postthrombotic vein may no
longer be compressible and compression ultrasound is less
. Table 3.3 Prospective therapeutic studies of patients with clinically suspected deep vein thrombosis (DVT) of the legs and diagnostic
workup based on compression ultrasound of the proximal leg veins including the popliteal vein using the algorithms presented in
. Fig.3.21a (According to Bounameaux 2002)
Study Cogo 1998 Bernardi 1998 Wells 1997 Perrier 1999
Diagnostic tests rCUS rCUS + DD rCUS + PP CUS+DD+PP
Diagnostic algorithm (see .
Number of patients 1702 946 593 474
Prevalence of thrombosis 24% 28% 16% 24%
PP – – Score Empirical
DD – Yes – Yes
CUS 100% 100% 100% 73%
rCUS 76% 9% 28% 0%
Abnormal rCUS 0.9% 5.7% 1.8% –
Venography 0% 0% 6% 0.4%
3-month risk of thromboembolism in untreated
group
CUS compression ultrasound, rCUS repeat compression ultrasound, DD
Fig.3.21a)
1 2 4 3
0.7% 0.4% 0.6% 2.6%
d-dimer test, PP estimation of pretest probability
192
Chapter 3 · Extremity Veins
specic in diagnosing recurrent thrombosis (false positive
results). ere are several sonographic ndings that suggest
recurrent thrombosis. One is the presence of a markedly
dilated, incompressible vein segment (. Fig.3.26c) proximal
to a partially recanalized venous segment (with demonstra-
3
tion of ow by color duplex). Another sonographic criterion
indicating recurrence is a central ow void that represents
a thrombus surrounded by owing blood (comparable
to the rubber phenomenon in venography). In contrast,
restored ow in a formerly thrombosed segment tends to
occur centrally and take a meandering course (. Fig.3.23).
Incompressibility of a previously normal vein segment is
nearly 100% diagnostic of recurrent thrombosis but requires
meticulous documentation of serial ultrasound ndings for
comparison (Prandoni et al. 1993). It is therefore recommended to perform a comprehensive color duplex ultrasound evaluation at the end of anticoagulation treatment
(usually 6months aer the onset of thrombosis) to establish
a new baseline for future examinations, typically when recurrence is suspected on clinical grounds.
Patients with complete recanalization following an episode of acute vein thrombosis and at least partially competent valves (based on duplex testing of reux) can be allowed
to discontinue elastic compression stocking therapy (Ten
Cate-Hoek etal. 2010).
3.1.6.1.1 Controversy About theUltrasound
Strategy inSuspected Deep Vein
Thrombosis
Abbreviated examination protocols not including the veins
below the knee in the diagnostic evaluation of patients with
clinically suspected lower extremity deep vein thrombosis
(DVT) are mainly used in North America. e rationale for
only examining the venous territory from the inguinal ligament to the tibiobular junction is that the risk of pulmonary
embolism from thrombosed veins below this level is very low
(<3%) and that postthrombotic changes in the calf veins have
little clinical relevance. If the calf veins are not included, then
one can just as well restrict compression ultrasound evaluation to two representative sites (
a relevant loss of information. e two sites are:
5 the femoral bifurcation (i.e., the segment from the ingui-
nal ligament to the conuence of the supercial and
deep femoral veins) and
5 the popliteal vein (i.e., from the adductor canal to the
tibiobular junction) (. Fig.3.22).
e justication for the two-point strategy is that isolated
femoral vein thrombosis is extremely rare (Frederick etal.
1996; Pezzullo etal. 1996). e junction of the external iliac
and common femoral vein is virtually always involved in
descending thrombosis, while the popliteal vein is involved
in ascending thrombosis arising in a calf vein. Isolated
supercial femoral vein thrombosis is virtually conned
to individuals with duplication of this vein (see . Fig.3.58
(Atlas)). In duplication, one branch may be thrombosed and
the other patent (Cogo etal. 1998). e other exception is
two-point strategy) without
thrombophlebitis with thrombus growth into the femoral
vein through a Dodd perforator.
Proponents claim that not including the supercial femoral vein in the sonographic workup of suspected lower extremity thrombosis reduces the examination time by 30–50%. Two
large prospective randomized studies (each including approx.
1000 patients) conrm that the rate of thromboembolism is
not much higher in patients examined using the
strategy
undergoing whole-leg ultrasound (Bernardi et al. 2008;
Gibson etal. 2009). In the study of Bernardi etal., the thrombotic complication rate was 1.2% in the whole-leg ultrasound
group versus 0.9% in the two-point ultrasound group. In the
latter group, ultrasound was repeated aer 1week if the initial
examination was negative but the D-dimer test was positive.
(2009), 1002 consecutive patients with suspected DVT
underwent clinical probability assessment and a D-dimer
test. In this way, 481 (48%) of patients with low clinical probability and normal D-dimer ndings were excluded (0.4%
thromboembolic complication rate), and the remaining
patients were randomized to a complete compression ultrasound examination or a rapid protocol, which examines the
veins in the groin and the knee. DVT was conrmed in 23%
of the 257 patients who underwent two-point ultrasound and
in 38% of the 264 patients who underwent a complete examination. e incidence of venous thromboembolism during
follow-up was 2% in the former and 1.2% in the latter.
remains a problem for the two-point protocol, the risk of
thromboembolic complications arising from missed calf
vein thrombosis appears to be much lower than expected.
In the above-quoted study of Gibson etal. (2009), the rate
of missed thromboses was 65%; however, only a small
number of additional thromboembolic complications were
observed (4 versus 2 patients or 2% versus 1.2%) compared
with patients examined by whole-leg compression ultrasound including the calf veins. A higher rate of venous
thromboembolism in patients with untreated isolated calf
thrombosis was found in the CALTHRO study (Palareti
etal. 2010). In this study, ultrasound was positive in 15.3%
of 431 patients examined for isolated calf vein thrombosis. While untreated calf vein thrombosis progressed to the
proximal main vein (popliteal vein) in only 3.1% of cases,
the 3-month thromboembolic complication rate was signicantly higher in the group with calf vein thrombosis
than in the group without calf vein thrombosis (7.8% versus 0.8%, p=0.003). However, not counting two patients in
whom repeat ultrasound aer 1week detected ascending
thrombus growth, the dierence became barely signicant
(4.7% versus 0.8%, p=0.049).
found good safety proles for complete proximal and distal
ultrasound examinations versus examinations limited to the
proximal veins with similar pooled estimates of the 3-month
thromboembolic rate (0.6% versus 0.4%). However, they
also found that calf vein thrombosis accounted for 50%
(. Fig.3.22) plus D-dimer test compared to patients
In the prospective management study of Gibson etal.
While detection of isolated calf vein thrombosis
e authors of a meta-analysis (Righini et al. 2005)
two-point
ab c
3.1 · Pelvic andLeg Veins
193
3
. Fig. 3.22a–c Diagnostic evaluation of patients with suspected deep vein thrombosis (DVT) of the legs using compression ultrasound. There is
no agreement about the venous segments that should be included in the examination. a Compression ultrasound from the inguinal ligament to
the distal popliteal vein using a standardized algorithm (see . Fig.3.21); this approach is based on the assumption that calf vein thrombosis rarely
causes thromboembolic complications. b Reduced examination of the femoral vein (from the inguinal ligament to just below the site of entry of
the deep femoral vein) and of the popliteal vein (two-point strategy). This approach assumes that isolated thrombosis of the supercial femoral
vein is rare, which is why this vein is not included in the examination. c Compression ultrasound from the inguinal ligament to the distal portion
of the calf veins (whole-leg strategy). The anterior tibial vein need not be included in the basic examination (except in patients with trauma of the
anterior compartment) as no cases of isolated anterior tibial thrombosis have yet been reported
of patients with positive ndings in the series undergoing
whole-leg ultrasound, concluding that searching for distal
deep vein thrombosis potentially doubles the number of
patients given anticoagulant therapy and may result in overtreatment.
e controversy about the
evance of isolated calf vein thrombosis
clinical and therapeutic rel-
and its diagnosis
is not over. e risk of thromboembolic complications and
late valve failure is considered to be low (Moser and LeMoine
1981). Moreover, experience also suggests that many patients
with calf vein thrombosis will never develop symptoms. ere
is only one study showing a signicantly increased rate of
thromboembolic complications in patients not treated by longterm anticoagulation for calf vein thrombosis (Lagerstedt etal.
1985), and this was in a rather small patient population. Other
authors have shown that isolated calf thrombosis will progress
proximally into the popliteal vein and farther in about 20%
of untreated patients (Kakkar etal. 1969; Langerstedt 1985;
Cornus etal. 1999; Gottlieb etal. 2003).
Even less scientic evidence is available on the signi-
cance of muscle vein thrombosis
. In the clinical setting,
though, we keep encountering patients with popliteal vein
thrombosis that has arisen from isolated soleus vein thrombosis. is is especially common in the elderly, in whom
these veins are dilated. e soleus veins drain into the posterior tibial and bular veins, and thrombus growth into the
major deep veins of the calf was observed in 16% of cases.
Gastrocnemius veins drain into the popliteal vein, and here,
growth into the popliteal vein was observed in only 3% of
cases over a period of 2weeks. is can be interpreted to justify short anticoagulation treatment. Because dilated thrombosed veins are tender, the patient can direct the examiner
to the disease focus during the compression ultrasound
examination. Dilated calf veins are more conspicuous sonographically, making them easier to identify than normal or
collapsed veins (. Figs.3.17 and 3.19).
In conclusion, although isolated calf vein thrombo-
sis as such rarely causes thromboembolic complication
timely anticoagulation treatment is indicated to prevent
proximal progression
. In the German-speaking countries,
the general strategy is to include the calf veins in the compression ultrasound examination of patients with suspected
,