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C.Y. Kim and C.J. Guevara
venous catheter or a single peripheral IV at any
site using indirect imaging. MRV is the preferred
method for evaluation of the central veins
because the excellent signal intensity generated
by gadolinium agents allows excellent visualization with indirect injection [ 12 ]. With time-
resolved MRA, the contrast bolus can be
visualized passing through the vasculature in
real-time manner, which allows excellent evaluation of collateral veins and routes of preferential
blood fl ow. High-spatial resolution imaging can
also be performed, allowing accurate characterization of lesions. Due to the image acquisition
time, breath-holding is required for high-spatial
resolution images. In severely compromised
patients, this can be diffi cult to impossible. CTV
of the central veins has also been shown to be
useful. The spatial resolution is superior to MRA,
and soft tissue characterization is superior, which
can be useful for diagnosing any compressing
masses or associated lung tumors. Furthermore,
the extremely rapid acquisition time requires
only a brief breath-hold. However, the contrast
opacifi cation during indirect imaging is not
nearly as robust as with MR, and direct imaging
can result in substantial mixing artifacts with
non-opacifi ed blood. Furthermore, a signifi cant
ionizing radiation dose to the thorax is required.
References
1. Ellis JH, Cohan RH. Reducing the risk of contrastinduced nephropathy: a perspective on the controversies. AJR Am J Roentgenol. 2009;192(6):1544–9.
2. Sidhu PS, Alikhan R, Ammar T, Quinlan DJ. Lower
limb contrast venography: a modifi ed technique for
use in thromboprophylaxis clinical trials for the accurate evaluation of deep vein thrombosis. Br J Radiol.
2007;80(959):859–65.
3. Katz DS, Hon M. Current DVT imaging. Tech Vasc
Interv Radiol. 2004;7(2):55–62.
4. Won YD, Lee JY, Shin YS, Kim YS, Yoon SA, Kim
YS, Hahn ST, Park SC, Kim YO. Small dose contrast
venography as venous mapping in predialysis patients.
J Vasc Access. 2010;11(2):122–7.
5. Krishan S, Panditaratne N, Verma R, Robertson
R. Incremental value of CT venography combined with pulmonary CT angiography for the
detection of thromboembolic disease: systematic
review and meta-analysis. AJR Am J Roentgenol.
2011;196(5):1065–72.
6. Ciccotosto C, Goodman LR, Washington L, Quiroz
FA. Indirect CT venography following CT pulmonary
angiography: spectrum of CT fi ndings. J Thorac
Imaging. 2002;17(1):18–27.
7. Lin YT, Tsai IC, Tsai WL, Chen MC, Lin PC, Chan
SW, Chen CC. Comprehensive evaluation of patients
suspected with deep vein thrombosis using indirect
CT venography with multi-detector row technology:
from protocol to interpretation. Int J Cardiovasc
Imaging. 2010;26 Suppl 2:311–22.
8. Jung SC, Lee W, Chung JW, Jae HJ, Park EA, Jin KN,
Shin CI, Park JH. Unusual causes of varicose veins in
the lower extremities: CT venographic and Doppler
US fi ndings. Radiographics. 2009;29(2):525–36.
9. Min SK, Kim SY, Park YJ, Lee W, Jung IM, Lee T,
Ha J, Kim SJ. Role of three-dimensional computed
tomography venography as a powerful navigator for
varicose vein surgery. J Vasc Surg. 2010;51(4):893–9.
10. Ruehm SG, Zimny K, Debatin JF. Direct contrastenhanced 3D MR venography. Eur Radiol. 2001;
11(1):102–12.
11. Kim CY, Miller Jr MJ, Merkle EM. Time-resolved
MR angiography as a useful sequence for assessment
of ovarian vein refl ux. AJR Am J Roentgenol.
2009;193(5):W458–63.
12. Kim CY, Merkle EM. Time-resolved MR angiography of the central veins of the chest. AJR Am J
Roentgenol. 2008;191(5):1581–8.
13. Müller MA, Mayer D, Seifert B, Marincek B, Willmann
JK. Recurrent lower-limb varicose veins: effect of
direct contrast-enhanced three-dimensional MR venographic fi ndings on diagnostic thinking and therapeutic decisions. Radiology. 2008;247(3):887–95.
14. Butty S, Hagspiel KD, Leung DA, Angle JF, Spinosa
DJ, Matsumoto AH. Body MR venography. Radiol
Clin North Am. 2002;40(4):899–919.
15. Prince MR, Zhang HL, Prowda JC, Grossman ME,
Silvers DN. Nephrogenic systemic fi brosis and its
impact on abdominal imaging. Radiographics. 2009;
29(6):1565–74.
16. Vogt FM, Herborn CU, Goyen M. MR venography. Magn Reson Imaging Clin N Am. 2005;13(1):
113–29, vi.
17. Wolpert LM, Rahmani O, Stein B, Gallagher JJ,
Drezner AD. Magnetic resonance venography in the
diagnosis and management of May-Thurner syndrome. Vasc Endovascular Surg. 2002;36(1):51–7.
18. Demondion X, Herbinet P, Van Sint Jan S, Boutry
N, Chantelot C, Cotten A. Imaging assessment of
thoracic outlet syndrome. Radiographics. 2006;
26(6):1735–50.
19. Ganeshan A, Upponi S, Hon LQ, Uthappa MC,
Warakaulle DR, Uberoi R. Chronic pelvic pain due to
pelvic congestion syndrome: the role of diagnostic
and interventional radiology. Cardiovasc Intervent
Radiol. 2007;30(6):1105–11.
Part III
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S u p e r fi cial Vein Therapy
Endovenous Thermal Ablation
https://t.me/med1917
Mark N. Isaacs
10
Contents
10.1 Introduction ................................................. 135
10.2
Endovenous Radio- Frequency
Ablation ........................................................ 136
10.3
Endovenous Laser Ablation ....................... 136
Patient Selection .......................................... 137
10.4
10.5
Contraindications ........................................ 138
10.6
Mechanisms of Action ................................. 138
Procedure ..................................................... 139
10.7
10.8
Efficacy: ELA............................................... 144
10.9
Efficacy: ERA .............................................. 144
Complications and Adverse Events ........... 145
10.10
10.11
Summary ...................................................... 145
References
................................................................. 146
Abstract
Prior to the introduction of endovenous
ablation, surgery was considered the only
effective treatment option for venous insufficiency caused by saphenous venous reflux.
Lack of patient acceptance and discouragingly high rates of varicose vein recurrence
have led to efforts to find less traumatic, more
cost-effective, and more successful methods of treatment. Two such methods include
endovenous chemical and endovenous thermal ablation. Endovenous thermal ablation
will be discussed in this chapter. When compared to traditional surgery, these treatment
methods are associated with a faster patient
recovery and may prevent recurrent varicose
veins due to neovascularization. The use of
perivenous tumescent anesthesia has largely
eliminated the adverse effects that were associated with earlier generations of equipment
and protocols.
10.1 Introduction
M.N. Isaacs, MD, FACPh, FAAFP, RPhS
Vein Specialists of Northern California,
Walnut Creek, CA, USA
e-mail: misaacs@veinspec.com
E. Mowatt-Larssen et al. (eds.), Phlebology, Vein Surgery and Ultrasonography,
DOI 10.1007/978-3-319-01812-6_10, © Springer International Publishing Switzerland 2014
Reflux from the deep system into the great and
small saphenous veins is recognized as the major
cause of varicose veins in the saphenous tributaries. Prior to the introduction of endovenous ablation, surgery was considered the only effective
treatment option for venous insufficiency caused
by this type of venous reflux. Lofgren and colleagues felt that surgery could be effective if
every abnormal junction between the deep system
135
136
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M.N. Isaacs
and the refluxing vein along with all refluxing
tributaries could be meticulously exposed and
eliminated [1, 2]. Other studies, however, have
shown a high rate of recurrent reflux, generally
thought by contemporary reviewers to be due to
neovascularization [3–6].
Lack of patient acceptance and discouragingly
high rates of varicose vein recurrence have led to
efforts to find less traumatic, more cost-effective,
and more successful methods of treatment. Two
such methods include endovenous chemical and
endovenous thermal ablation. Endovenous thermal ablation will be discussed in this chapter
while endovenous chemical ablation will be covered in Chap. 11. While cryotherapy technically
could be considered thermal ablation (and there
are studies in the literature addressing this method
of treatment), this form of therapy is not commonly accepted in the medical community and
will not be described in this chapter.
In endovenous thermal ablation, a catheter
threaded into the refluxing vein generates an
extreme temperature resulting in damage to the
inner aspect of the vein wall and obliteration of
the vein lumen. Attempts to utilize endovenous
thermal energy to ablate the abnormal great
saphenous vein date back to at least the 1950s
when a “monoactive” electrode was introduced
in Eastern Europe and later modified to a “biactive” electrode a decade later [7]. These early
catheters were usually passed from the surgically
ligated saphenofemoral junction distally to the
ankle. Electrically generated heat was monitored
by the surgeon’s hand on the skin surface.
Though short-term results in eliminating reflux
were encouraging, there was a high rate of complications due to thermal damage to adjacent
tissues.
10.2 Endovenous Radio-
Frequency Ablation
In the late 1990s and early 2000s, two methods
of heat catheter treatment emerged: endovenous radiofrequency ablation (ERA) and endovenous laser ablation (ELA). ERA, the first
method to gain Food and Drug Administration
(FDA) approval in the USA, was introduced
by the VNUS Medical Technologies Company
of Sunnyvale, California (later acquired by
Covidien). The Closure Plus™ and Restore™
catheters had sheathed fans of electrodes at their
tips utilizing a computer-controlled bipolar generator. Unlike earlier electrode-type catheters,
these catheters allowed for instantaneous monitoring of impedance and vein wall temperature.
Feedback loop circuitry maintained thermal
energy in the vein wall within specified parameters during continuous pullback, providing controlled heating adequate to denature collagen in
the vein wall.
Early published results of treatment trials
revealed problems with thermal injury to skin
and adjacent nerves causing necrosis and paresthesias, clinical thrombophlebitis, and propagation of thrombus into the femoral vein [8]. The
treatment protocol was modified to begin treatment 2 cm from the actual saphenofemoral junction and to include subcutaneous fluid injection.
The later introduction of perivenous tumescent
anesthesia largely eliminated heat-related complications and the need for general anesthesia
(see Sect. 10.7).
Problems with char developing on the electrodes, slow pullback speed, and the need for a
cumbersome compression wrap during treatment led to the VNUS Company to develop a
new generation of radio-frequency catheters
(ClosureFast™) that utilize segmental ablation. The elimination of fragile electrodes and
the need for elastic compression have made the
ClosureFast™ the leading radio-frequency catheter in the USA (Figs.
The Olympus Celon RFITT™ from Olympus
Medical Systems of Hamburg, Germany, is an
alternative system that has yet to be FDA
approved for use in the USA.
10.1 and 10.2).
10.3 Endovenous Laser Ablation
The first report of the use of laser for ELA was in
1999 from Dr. Boné in Spain [9]. This was followed by two reports in the American literature
describing treatment of the great saphenous vein
10 Endovenous Thermal Ablation
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Fig. 10.1 The ClosureFast™ radio-frequency catheter
(Copyright
®
Covidien. Used with permission)
utilizing an 810 nm diode laser from Diomed and
a 600 μm laser fiber (Fig. 10.3) [10, 11]. Since
then, a number of lasers with different wavelengths have been introduced for endovenous laser
treatment of both the great and small saphenous
veins, often with accompanying reports purporting to show a therapeutic advantage of the newly
introduced wavelength [
12–15]. The suggestion is
that higher wavelengths target water over hemoglobin, leading to fewer side effects (see discussion under Sects. 10.8 and 10.9) [16, 17].
The technique initially used during the FDA
trials for ELA involved pulses of laser energy at
specified intervals during pullback. With time,
the technique was modified to employ continuous pullback with energy calculated as joules per
linear centimeter. Unlike the ERA catheter, laser
fibers have no feedback loop control, and the
energy delivered to the vein wall is a function of
both the power setting used and the pullback
speed.
137
10.4 Patient Selection
Patient selection and preoperative evaluation are
the same for both methods of endovenous thermal ablation. Both rely heavily on an accurate
ultrasound evaluation of the superficial venous
system, making the role of the ultrasonographer
crucial. The recommended protocol for diagnosing and mapping reflux in the superficial system
is different from the traditional protocol for evaluation of the deep veins [18]. For this reason, it is
highly desirable for the treating physician to
become appropriately credentialed in doing this
examination or to work with a technician with
demonstrated experience and skill.
The vast majority of patients with venous
insufficiency have reflux in the great saphenous
and/or the small saphenous vein. The extent of
reflux in these veins must be meticulously
mapped prior to treatment along with refluxing
tributary veins and perforators. Indeed, it might
be theorized that the disappointing rates of success reported with surgery in past decades had as
much to do with the unavailability of adequate
ultrasound mapping as with the treatment method
itself. While an alternative strategy has adherents
(mostly in Europe) [19, 20], the majority of
phlebologists in the USA believe that the most
effective treatment for long-term elimination of
superficial venous insufficiency is to ablate all
incompetent junctions with the deep system
along with all major pathways of reflux [3, 8].
The ideal candidate for endovenous thermal
ablation is the patient with a single, principle
route of reflux that is relatively straight and easily
accessible directly or via a tributary by percutaneous puncture or by limited surgical exposure.
The patient with an enlarged, refluxing great or
small saphenous vein is ideal. Patients with isolated abnormal tributary veins, often the anterior
or posterior circumflex vein, are also candidates
if the proximal portion of the vein is straight
enough for the catheter to pass easily. Reflux
from incompetent perforators can also be treated,
though this technique requires experience and
skill in order to precisely maneuver the catheter/
fiber tip to the perforator junction. Patients with
multiple routes of reflux also can be treated,
138
and collapses
closing vein
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M.N. Isaacs
Disposable catheter
inserted into vein
Fig. 10.2 Radio-frequency endovenous thermal ablation with the ClosureFast™ catheter (Copyright ® Covidien. Used
with permission)
though more than one treatment session might be
required, both for logistical reasons and because
superficial veins tend to spasm once one vein has
been traumatized.
While the use of the original Closure Plus™
catheter was limited to veins with a diameter of
2–12 mm, no such size limitation exists for either
the ClosureFast™ or laser fibers. While a vein
may look extremely large when the patient is
Vein heats
Catheter withdrawn,
of circulation is a major contraindication if the
vein to be treated is a major pathway for venous
return.
Relative contraindications include morbid
obesity, pregnancy, nursing, significant hypercoagulopathy, nonambulatory status, peripheral
arterial disease, lymphedema, and disease states
that could inhibit adequate healing such as
uncontrolled diabetes mellitus.
upright, the combination of supine position and
tumescent anesthesia empties the vein enough to
dramatically reduce the vein diameter.
10.6 Mechanisms of Action
The original VNUS Closure Plus™ catheter
10.5 Contraindications
directly heated tissue surrounding the active electrode to a temperature of 85 °C utilizing resis-
Contraindications include allergy to local anesthetic used in tumescent solution, an implanted
device that could be affected by radio frequency,
complete anatomic or thrombotic obstruction
in the vein to be treated, and recent or active
thromboembolic disease. Deep vein occlusion in
which the superficial veins form a collateral route
tance to RF current. At this temperature, collagen
denaturation and contraction cause vein shrinkage. Ideally, subsequent endothelial damage
causes a fibrotic reaction, eventually occluding
the vein lumen. The introduction of subfascial
tumescent anesthesia virtually eliminated early
problems with heat-related damage to adjacent
10 Endovenous Thermal Ablation
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139
tissues [22]. Available since 2006, the VNUS
ClosureFast™ segmental ablation catheter utilizes an increased target temperature of 120 °C.
There is some controversy regarding the
mechanism of heat generation by laser fibers.
Theoretically, lower wavelength lasers (810, 940,
980 nm) target hemoglobin, while higher wavelength lasers target water. It has been suggested
from in vitro studies that hemoglobin-targeting
lasers are more likely to generate diffuse, high
temperatures and steam bubbles that affect a
larger surface area of vein wall compared to
water-targeting lasers [23]. Conversely, it has
been proposed that it is precisely this lack of
hemoglobin targeting in a 1,320 nm laser that
results in less postoperative pain and ecchymosis
[24]. Whatever the mechanism, both types of
laser will damage the endothelial lining of the
vein, thereby initiating a process of fibrosis that
eventually occludes the vein lumen.
10.7 Procedure
ERA and ELA are both endovenous thermal
ablation methods, and they have many procedural steps in common. Once comprehensive
ultrasound mapping of the sources and routes
of reflux is accomplished, patient consent is
obtained as it would be with any medical procedure. Though the risks of endovenous ablation
are far lower than equivalent surgery, the procedure is not without significant potential morbidity, and a thorough informed consent process is
essential [
ing choose the operating room as the setting for
the procedure, endovenous ablation can be
accomplished safely and expeditiously in the outpatient setting. A table that allows adjustments in
height and body angle is desirable. The room
should be large enough to allow the presence of
the ultrasound machine, the ERA or ELA equipment, at least one assistant, and a large table upon
which a sterile field can be established. The presence of a sonographer to facilitate direct visualization of the target veins is highly desirable,
though some advanced practitioners choose to
12–16].
While some phlebologists with surgical train-
hold the ultrasound probe with one hand while
manipulating the catheter with the other.
Preoperative marking on the skin of the vein to
be treated along with any deep vein junctions
may be helpful. A low dose of a short-acting oral
sedative medication such as alprazolam 0.5–
mg may help the patient relax and thereby
1.0
help prevent vein spasm.
Patient positioning depends on the vein to be
treated. For the great saphenous vein and/or its
major tributaries, the patient is usually positioned
supine with the leg externally rotated. Some
operators elevate the leg in order to ensure that
blood is emptied from the vein lumen as much as
possible, but there is no evidence that this position yields better results or reduces complications. For the small saphenous vein, the patient
is positioned prone with a pillow under the feet
for comfort. The skin is scrubbed with antiseptic
solution and a sterile field is established in the
usual fashion. Care must be taken to make sure
the ultrasound probe is covered with a sterile
condom and that sterile ultrasound gel is used.
Since veins may move relative to the skin surface
during patient positioning on the table, a brief
ultrasound exam to reidentify the target vein is
advisable.
Ideally, the catheter should be inserted at the
most distal site at which reflux is documented
in order to achieve optimum results from the
initial treatment [11]. In reality this may be difficult due to the tortuous anatomy of distal segments or inadvisable due to the close proximity
of the saphenous nerve to the great saphenous
vein below the knee and the sural nerve to the
small saphenous vein in the lower third of the
calf. While some practitioners feel that adequate
tumescent anesthesia protects against damage
to an adjacent nerve [
titioners choose to insert the catheter at or just
below the knee in the case of the great saphenous
and at or above the mid-calf in the case of the
small saphenous. The actual technique of insertion depends on the kit being used, the recommendations of the equipment manufacturer, and
the experience of the operator. Most kits include
a J-wire that is inserted through a needle followed by an introducer threaded over the J-wire.
14, 17–23], many prac-
saphenous v
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140
Saphenofemoral
junction
Femoral
artery
Femoral vein
Laser
fibre
Greater
ein
Fig. 10.3 Endovenous laser fiber ablating the great
saphenous vein (Photo courtesy of AngioDynamics, Inc.)
The catheter or fiber is then threaded through the
introducer.
With experience, percutaneous puncture of the
vein under direct ultrasound visualization is
almost always possible, though occasionally a
small cutdown might be necessary. Superficial
infiltration of the skin with local anesthetic is the
only anesthesia required. Whether the ultrasound
image is transverse or longitudinal during the
puncture is a matter of preference, but once the
radio-frequency catheter or laser fiber is introduced into the lumen of the vein, the probe should
be held longitudinally to follow the course of the
catheter as it is advanced toward the deep vein
junction.
M.N. Isaacs
While early protocols called for the catheter or
fiber tip to be positioned close to the deep vein
junction, two factors have altered the thinking
about positioning. An early study of ERA showed
a disturbingly high incidence of thrombus extending from the area of treatment through the junction into the deep vein lumen, in one case causing
a true deep vein thrombosis with resulting pulmonary emboli [
8]. Also, it became clear with
experience, as well as from surgical literature on
varicose vein recurrence [5, 25], that preserving
normal routes of drainage of high tributaries from
the groin and abdomen into the proximal saphenous trunk (in the case of the great saphenous)
helps prevent recanalization and neovascularization. While this concept is hard for some surgeons to accept given the traditional emphasis on
ligation flush to the deep vein, positioning the
catheter 1–2 cm from the deep vein junction or
below the junction of the superficial epigastric
vein is now the accepted norm in most centers
(Fig. 10.4) [11].
Once the catheter is correctly positioned
(Fig. 10.5), the next step is the intrafascial infiltration of tumescent anesthetic. As has been previously stated, general anesthesia for endovenous
ablation is neither necessary nor recommended
due to the increased risk of heat-related damage
to adjacent tissue structures and the risk of DVT
due to lack of early ambulation. Properly administered tumescent solution not only provides adequate anesthetic effect for patient comfort but
also acts as a heat sink to prevent transmission of
thermal energy beyond the immediate zone of the
vein wall. An additional benefit of perivenous
anesthetic fluid is the resulting compression of
the treated vein, allowing better contact between
the endovenous catheter tip and the vein wall.
Even very large diameter veins can be adequately
compressed using this technique. The most commonly used solutions are 0.1 and 0.2
% lidocaine
with sodium bicarbonate added as a buffer. The
addition of epinephrine prolongs the anesthetic
effect by reducing absorption. The recommended
maximum dose of lidocaine with epinephrine is
7 mg/kg, but higher doses are reported to be safe.
A solution of 0.1 % lidocaine can be made by
diluting 100 cc of 1 % lidocaine with 900 cc of
Vein collapse and catheter withdrawal
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Laser fiber in vein prior to activation
141
Saphenofemoral
junction
Laser fiber
Femoral vein
Femoral artery
Great saphenous vein
Femoral nerve
Collapsed GSV
Laser fiber
Fig. 10.4 Endovenous catheter tip shown advanced to just distal to the superficial epigastric vein, approximately 2 cm
from the deep vein junction
normal saline, then adding 10 cc of 8.4 % sodium
bicarbonate.
Of all the skills necessary to perform endovenous thermal ablation, infiltration of tumescent
anesthesia is probably the hardest for the beginner to learn. Briefly, the injecting needle is
advanced under ultrasound guidance until the tip
looks like it is just contacting the vein wall closest to the skin surface. When fluid is then injected,
it will be seen to be contained within a distinct
compartment superficial to the vein but deep to
the subcutaneous layer. Whether a pump is used
or the injection is done manually, the needle is
advanced within the fluid pocket along the length
of the vein until the entire vein segment, including
the area of the deep vein junction, is infiltrated.
Should it be necessary to advance the needle
deep into the catheter or fiber, care must be exercised to avoid causing damage by direct contact
between the sharp needle tip and the catheter or
laser fiber.
Figure shows the great saphenous vein in longitudinal view with the injecting needle within
the plane of the saphenous fascia as fluid is being
injected. The second image is a transverse view
of the same vein several minutes after injection.
As is illustrated, though the anesthetic fluid is initially injected superficial to the vein wall but deep
to the fascia, it soon spreads circumferentially to
completely surround the vein within the fascial
142
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Fig. 10.5 Diagnostic ultra-
sound images showing catheter
placement during endothermal
venous abiation. (a) Transverse
view. (b) Longitudinal view
(Courtesy: Mark N. Isaacs)
M.N. Isaacs
a
compartment. This method of tumescent anesthetic injection is more effective in providing
complete anesthesia for the patient, as well as in
absorbing heat, than non-intrafascial subcutaneous infiltration of larger volumes of fluid.
After the administration of the tumescent
anesthetic, but before ablation is begun, there is
the opportunity to use ultrasound-guided sclerotherapy to treat refluxing distal segments and tributaries. Either foam or liquid sclerosant can be
used for this purpose, though foam is considered
to be more effective. Foam does carry some risk,
b
however, of drifting into the catheterized portion
of the vein and obscuring the ultrasound view of
the catheter, and at this time, foam is considered
an “off-label” use of FDA- approved sclerosant.
It is also perfectly reasonable to treat these additional veins at a later date by either sclerotherapy
or phlebectomy.
Anesthetic is usually injected at the deep vein
junction last, yet this is the area that will be
ablated first. Because anesthetic can take several
minutes to be fully effective, it is wise to delay
briefly before starting the endovenous ablation
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