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228 Ultrasound Guidance for Endovenous Treatment
obtained. Comorbidities, allergies, and pharmacologic history must be
documented.
2
The BMI is calculated from the patient’s height and weight
and should be recorded.
The patient should be examined in a standing position to demonstrate
visual patterns of telangiectasias, reticular, and varicose veins.
5
This should
be supplemented by cold light trans-illumination of the skin with a bright
white light, such as the Vein Light, to identify reticular veins. A handheld
Doppler device can serve to perform a screening examination, but it should
be considered to be inadequate to plan specifi c treatment.
5
Three levels of pathologic veins are evaluated using the techniques cited
in the preceding paragraphs. Telangiectasias in the skin are visually
inspected; reticular veins are trans-illuminated with the vein light; and
varicosities and the saphenous veins, with ultrasound. Clinical data should
be integrated into the CEAP classifi cation.
6,7
EQUIPMENT
The ultrasound duplex scanner should be able to detect blood fl ow rates
as low as 6 cm/second.
2
Dedicated high-resolution vascular scanners with
color and/or Power-Doppler functions as well as the continuous wave
Doppler can do this. Linear transducers in the range of 4–7 megahertz
(MHz) are used.
5,8
The inferior vena cava, pelvic veins, and deep veins of
the limbs in obese patients may be imaged with lower frequency, 3-MHz
transducers.
1
Linear hockey-stick transducers in the range of 5–12 MHz
will provide detailed imaging of smaller veins and perforating veins.
After the year 2000, advances in technology allowed duplex scanners to
become smaller, more transportable, and more operator friendly.
5
These
miniaturized devices feature transducers designed with advanced architec-
ture that allow a single probe to image across a greater range of depths
within an application and across applications.
5
Thus, in many ways, the
portable ultrasound instrument supplements the stethoscope in patient
evaluation. The transducer for peripheral vascular examinations operates
from 10–15 MHz and provides resolution from skin surface to 7 cm in
depth.
5
The technology incorporates power Doppler sonography, tissue
harmonic imaging, and direct connectivity to a personal computer.
5
The
overall performance of miniaturized ultrasound devices is comparable to
the more traditional and much larger ultrasound equipment that allowed
establishment and growth of the vascular laboratory.
5
VENOUS TESTING AND MAPPING
Not only is a detailed U.S. duplex study of the normal and pathologic
venous anatomy essential, but a map should be created to guide therapy.
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Ultrasound Guidance for Endovenous Treatment 229
A detailed verbal description of the examination and its fi ndings is useful
for record purposes, but it is the map that is most useful during therapy.
A clear and illustrative graphic notation of signifi cant vein diameters,
anomalous anatomy, superfi cial venous aneurysms, perforating veins, and
the presence and extent of refl ux should always be recorded during the
examination (Figure 17-1).
2,5
As mentioned, the ultrasound examination is conducted with the patient
standing.
9
This position has been found to maximally dilate leg veins and
challenges vein valves. Sensitivity and specifi city in detecting refl ux
are increased in examinations performed with the patient standing rather
than when the patient is supine.
8,9
Supine examinations for refl ux are
unacceptable.
The veins are scanned by moving the probe vertically up and down
along their course. Transverse scans are most informative, but a mental
reconstruction must be created to record the venous map. Duplicated seg-
ments, sites of tributary confl uence, large perforating veins, and their deep
venous connections are identifi ed as well as the very common superfi cial
venous aneurysms. Location of abnormalities as measured in centimeters
from the fl oor assists in preparing a therapeutic guide. Measurements
FIGURE 17-1 This data entry form outlines the saphenous veins and the relevant deep
veins. Refl uxing veins are added in heavy black lines. Location of perforating veins and
aneurysms can be added and distance from the fl oor indicated. Diameters of perforating
veins at the fascial level should also be noted.
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230 Ultrasound Guidance for Endovenous Treatment
from the medial malleolus are commonly recorded but are not as precise.
Transverse, in, and longitudinal scans combined with continuous scanning
provide a clear mapping of the venous system.
Patency of peripheral veins is usually assessed by compression of the
vein with the transducer.
8
Residual, ancient thrombus, partial patency, and
extrinsic compression should all be noted in the verbal description of fi nd-
ings. Refl ux is detected by fl ow augmentation with compression and release
maneuvers of the thigh and calf. The Valsalva maneuver is used only at
the saphenofemoral junction
8
because presence of a competent proximal
valve negates the value of the examination.
Automated rapid infl ation and defl ation cuffs are in use but are cumber-
some. However, they do offer the advantage of a standardized stimulus,
10–1 2
which allows timing of refl ux. Although refl ux greater than 500 ms is con-
sidered pathologic,
9,13
this is only precisely accurate when a standard stimu-
lus is applied.
The diameter of the saphenofemoral junction and femoral vein are
recorded for use in preparation for radiofrequency VNUS closure® and
endovenous laser ablation.
14– 16
Important information is also gained from
diameters of the GSV at mid-thigh and distal thigh. Radiofrequency abla-
tio n i s c om monly us ed to tre at veins f ro m 2 to 12 m m i n d ia mete r,
16
although
diameters recorded with the patient standing do not apply when treatment
is given with the patient supine.
The supragenicular, infragenicular, or immediate subgenicular great
saphenous veins are often the access point for its laser or radiofrequency
ablation.
16,17
Therefore, the depth of the GSV in these regions should be
recorded.
Accessory veins, by defi nition, run parallel to the GSV in the thigh
18
(Figure 17-1); therefore, it is imperative to map their course accurately and
to note their eventual communication with GSV (Figure 17-1), as well as
their presence or absence of refl ux with relationship to varicosities. The
accessory veins are easily confused with the GSV during continuous lon-
gitudinal scanning when the saphenous vein appears to leave the saphe-
nous compartment.
18
This error is avoided when transverse scans are done.
The great saphenous vein is scanned throughout the leg and thigh so that
its tributaries are identifi ed (Figure 17-1).
The diameters of the popliteal vein and the small saphenous vein (SSV)
are recorded at the junction as well as diameters of the SSV along its course
in the leg. Intersaphenous veins should be identifi ed and the extreme vari-
ability of the SSV termination carefully recorded.
The venous refl ux examination also includes the mapping of exit and
re-entry perforating veins (PV) wherever they are identifi ed.
19
PV refl ux is
detected as outward fl ow duration greater than 350 ms during the release
phase of the fl ow augmentation maneuver (distal compression has higher
sensitivity in detecting PVs refl ux).
1
Perforating veins should be accurately
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Ultrasound Guidance for Endovenous Treatment 231
mapped in their different locations in the leg, and their position should be
measured as distance (cm) from the fl oor.
18,2 0
ULTRASOUND MONITORING DURING
ENDOVENOUS THERAPY
Endothermic coagulation is caused by the generation of or application
of heat to the endothelial surface of targeted veins.
16,21,22
It is been sug-
gested that the coagulation process is related to the intravascular vaporiza-
tion of blood (steam) during laser therapy with intimal denudation and
collagen fi ber contraction. Vein wall thickening and rapid reorganization
of the vessel to form a fi brotic cord follow.
21,22
Occlusion is usually visual-
ized within 10–20 seconds of the laser or radiofrequency energy applica-
tion.
22
Both techniques have been proven to be safe and effective.
23
Percutaneous introduction of the laser or RF catheter has made surgical
intervention less acceptable to patients because of post-treatment pain,
number of cutaneous incisions, and subsequent postprocedural disability
and recovery time.
15,16
Before the procedure starts, the patient’s limb should undergo repeat
scanning for procedural planning and identifi cation of the venous access
site and its relationship to perforating veins, varicosities, and areas of tor-
tuosity, stenosis, or dilation. In this preparatory phase, some anatomic
landmarks should be clearly recognizable. They include the femoral vein,
saphenofemoral junction, saphenous compartment, great saphenous vein,
and the small saphenous junctional anatomy.
The supragenicular saphenous vein is usually the access point of
choice for varicose vein treatment (Figure 17-2).
17
Introduction of the
echogenic needle and the introducer sheath is performed percutaneously
using the Seldinger technique. The intraluminal position of the sheath is
ascertained by easy passage of the guidewire and aspiration of nonpulsatile
venous blood. The sheathed laser fi ber or a 6- or 8-F VNUS catheter
is advanced to a point just distal to the entrance of the epigastric vein.
17
Position of the laser fi ber is confi rmed by direct visualization of the red
aiming beam and that of the VNUS catheter by ultrasound
16
(Figures 17-3
and 17-4).
The catheter or sheath appears as a hyperechoic line in the GSV
lumen.
14,1 5
Its placement must be precisely at the SFJ 1 cm distal to the
epigastric vein (Figure 17-4).
16
Administration of the low concentration anesthesia into the saphenous
compartment is monitored closely by ultrasound.
17
Correct placement of
anesthesia within the saphenous compartment is crucial for procedural
safety and success. The vein is seen as “fl oating” in the anechogenic sea of
the anesthetic solution (Figures 17-5A and 17-5B). It is always wise to
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232 Ultrasound Guidance for Endovenous Treatment
FIGURE 17-2 The great saphenous vein is cannulated using the Seldinger technique.
The puncturing needle is echogenic and can be easily visualized. (Adapted from Pichot O,
Atlas of Ultrasound Images, Copyright VNUS® Closure.)*
FIGURE 17-3 The laser catheter is advanced proximally toward the saphenofemoral
junction. Position of the laser fi ber is confi rmed by direct visualization of the red aiming
beam through the skin. (Adapted from Navarro L, Min RJ, Bone C. Endovenous laser: A
new minimally invasive method of treatment for varicose veins: Preliminary observations
using an 810 nm diode laser. Dermatol Surg. 2001;27(2):117.)
*http://www.vnus.com/navigation/PDFs/pichotultrasoundatlasweb.pdf
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FIGURE 17-4 Position of the guidewire and radiofrequency catheter is monitored by
ultrasound visualization. (Adapted from Pichot O, Atlas of Ultrasound Images, Copyright
VNUS® Closure.)*
FIGURE 17-5 Administration of the tumescent anesthesia into the saphenous compart-
ment is monitored by ultrasound. SFJ: saphenofemoral junction; T.A.: tumescent anesthesia.
(Adapted from Pichot O, Atlas of Ultrasound Images, Copyright VNUS® Closure.)*
*http://www.vnus.com/navigation/PDFs/pichotultrasoundatlasweb.pdf
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234 Ultrasound Guidance for Endovenous Treatment
recheck the catheter position at SFJ after correct placement of the limb
and prior to the application of energy (Figure 17-6).
22
Endovenous ablation starts at the saphenofemoral junction and pro-
ceeds in a distal direction.
16
Successful obliteration is confi rmed by con-
traction of the saphenous vein to a residual diameter of <2 m m.
16
Patency
of the common femoral artery and vein are confi rmed by ultrasound
(Figures 17-7A and 17-7B). Any thrombus is seen as a hyperechogenic core
in the vessel, although this is very uncommon (Figure 17-7B).
15,24
Early post-treatment duplex scanning should be performed. Conven-
tionally, this is done at 1 and 7 days postprocedure. Many have eliminated
the 1-day examination because deep venous thrombosis is uncommon and
thrombus protruding into the femoral vein is so benign. Evidence of a
protruding thrombus from the saphenous vein into the femoral vein should
be looked for, however, in every postprocedural examination (Figure
17-8).
24
Evidence of a noncompressible GSV with thickened walls and
absence of fl ow on color ultrasound analysis are signs of successful oblit-
eration (Figure 17-9).
9
ULTRASOUND MONITORING DURING
SCLEROFOAM TREATMENT
Advent of foam sclerotherapy has added a new tool for the treatment of
chronic venous insuffi ciency. Sclerosant agents provoke endothelial damage
by several mechanisms.
25
They change either the surface tension of the
plasma membrane (detergents) and/or the intravascular pH and osmolar-
ity. The fi nal result is a chemical fi brosis of the treated vessel.
25
FIGURE 17-6 The ablation starts at the saphenofemoral junction and proceeds in a
distal direction. It is always wise to recheck the catheter position at SFJ prior to the applica-
tion of energy. (Adapted from Pichot O, Atlas of Ultrasound Images, Copyright VNUS®
Closure.)*
*http://www.vnus.com/navigation/PDFs/pichotnavigationatlasweb.pdf
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Ultrasound Guidance for Endovenous Treatment 235
FIGURE 17-7 Duplex examinations (longitudinal views) of the great saphenous vein
(GSV) at the saphenofemoral junction (SFJ). A. A pretreatment scan demonstrated an
incompetent SFJ after augmentation. B. Intraoperative color duplex interrogation showed
successful occlusion of the GSV with a patent, 3-mm proximal stump (arrow 1) and absence
of fl ow within the treated segment (arrow 2). (Adapted from Puggioni A, Kalra M, Carmo
M, Mozes G, Gloviczki P. Endovenous laser therapy and radiofrequency ablation of the great
saphenous vein: Analysis of early effi cacy and complications. J Vasc Surg. 2005;42(3):
488–493.)
FIGURE 17-8 Early post-treatment duplex scanning should be performed. Evidence of
a protruding thrombus from the saphenous vein into the femoral vein should be looked for.
(Adapted from Pichot O, Atlas of Ultrasound Images, Copyright VNUS® Closure.)*
Sclerosing foams (SF) are mixtures of gas and a liquid solution with
surfactant properties. In 1993, Cabrera re-introduced the use of SF, made
of sodium tetradecyl sulfate or Polidocanol, in the treatment of varicose
veins.
26
One of the intrinsic limits of liquid sclerosants in treatment of
varicose veins is their dilution by blood, with reduction of their effi cacy.
27
Also, they are rapidly cleared by the moving bloodstream. Sclerosing foams
*http://www.vnus.com/navigation/PDFs/pichotultrasoundatlasweb.pdf
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236 Ultrasound Guidance for Endovenous Treatment
do not mix with blood and instead remain in the vessel where they strip
the endothelium.
27
Persistence of the agent in the vessel causes an increased
contact time with the intimal surface. Foam preparation is remarkably
simple.
27
Tessari’s three-way stopcock method is the most commonly
used.
27,28
As with endovenous ablation, the treatment starts with clear ultrasound
mapping. Varicose veins can be accessed by the placement of a 25-G but-
terfl y needle, or the great saphenous or small saphenous vein can be directly
cannulated with an angiocath, an echogenic Cook® needle, or a butterfl y
needle.
27,29,30
Nearly all descriptions of the technique explain direct
ultrasound-guided access to the saphenous vein.
27,31
In contrast, many expe-
rienced operators achieve a satisfactory and rapid obliteration of the GSV
and SSV by cannulating a peripheral varicosity.
30
Although the saphenous
vein cannot be cannulated with a catheter by way of a varicosity because
of its angle of connection, there is no such obstacle to the fl ow of foam.
Fo am fu nc tion s a s a n effi cie nt ul traso un d (US ) c ont ra st med iu m beca use
of its air content. Its instillation is easily monitored. Its US appearance is
that of a solid hyperechogenic core with an accompanying acoustic shadow
(Figure 17-10).
Foam is introduced into a varix or the saphenous vein with the patient
supine. As the foam reaches the SFJ as monitored by ultrasound, compres-
sion of the SFJ or the SPJ is usually done in order to preserve foam in the
limb.
FIGURE 17-9 Evidence of a noncompressible GSV with thickened walls and absence
of fl ow on color ultrasound analysis are signs of successful obliteration. (Adapted from
Pichot O, Atlas of Ultrasound Images, Copyright VNUS® Closure.)*
*http://www.vnus.com/navigation/PDFs/pichotultrasoundatlasweb.pdf
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Ultrasound Guidance for Endovenous Treatment 237
FIGURE 17-10 Foam functions as an effi cient ultrasound contrast medium because of
its air content. Its injection can be easily monitored. Its US appearance is that of a solid
hyperechogenic core with an acoustic shadow projected in the tissue below.
Vasoconstriction and vasospasm can be induced by intermittent com-
pression of the vein by the ultrasound transducer and by elevating the limb.
This minimizes the blood content of the treated veins. Foam will be seen
by ultrasound to fl ow distally in the elevated limb. It fl ows selectively
through incompetent valves and is blocked by competent valves. Femoral
compression and leg elevation have the effect of prolonging the action of
the foamed sclerosant on the distal intima, improving the effi cacy of the
entire treatment. In addition, leg elevation for 10 minutes or so allows
the foam to revert to its liquid state so that foam particles will not reach
the right atrium or a patent foramen ovale.
The femoral, popliteal, and deep veins of the leg are scanned intermit-
tently throughout the entire procedure. Foam particles are washed out of
deep veins such as the gastrocnemius or tibial veins by fl exion-extension
maneuvers of the foot. Repetitive dorsifl exion of the foot completely clears
the deep veins of any foam particles.
Despite much consternation, major thrombotic events have rarely been
described with use of sclerofoam. In a study of over 12,000 sclerotherapy
sessions by Guex, over half of which involved foam only, a single femoral
vein thrombus was encountered.
32
Thromboses of the gastrocnemius, tibial, and peroneal veins have been
reported occasionally, and intra-arterial injections are even more rare.
30,33
Ultrasound sonography has confi rmed the presence of a tangled network
of small varicose veins, reticular varices, and incompetent perforating
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