Comparative randomized Clinical trial of Radiofrequency
Ablation (VNUS )versus Steam Ablation for the treatment
of Great Saphenous Veins

Lower extremity venous insufficiency is a common medical condition. A
prevailing cause being an insufficiency of the GSV, approximately 30.000
patients are operated each year in Holland to exclude this insufficient GSV.
Since varicose veins increase with age the prevalence of venous insufficiency
will increase considerably. Classic symptoms of venous insufficiency are
aching, discomfort, edema, and muscle cramps. Associated complications are
eczema, lipodermatosclerosis, white atrophy, superficial thrombophlebitis, and
venous ulcers.
About 1% to 2% of people older than 65 years of age have (a history of) venous
ulcers. It has been estimated that half of the venous ulcers can be prevented
when varicose veins are treated. Chronic venous insufficiency has a great
impact on patients* health-related quality of life (HRQOL), which is comparable
to other common diseases. The treatment of varicose veins reduces the symptoms
and complications of chronic venous insufficiency and improves HRQOL of
patients. Surgery has been the
standard of care in the treatment of saphenous varicose veins. The great
saphenous vein (GSV) is traditionally treated by high ligation at the
saphenofemoral junction (SFJ) followed by a short stripping to the knee. Most
commonly, the small saphenous vein (SSV) is ligated at the saphenopopliteal
junction (SPJ) only. Recurrence rates after surgery are about 25% and 50% at 5
years for the GSV and SSV, respectively. A study with a mean follow-up of 34
years showed recurrence in 60% of 125 limbs after SFJ ligation and GSV
stripping. Failure after surgery may be due to neovascularization, double
saphenous vein system, technical and tactical failure (up to 30%) ,
and/or incomplete procedure. Other disadvantages of surgical therapy are the
use of general or epidural anesthesia, presence of at least two fairly long
scars, postoperative down-time, more tissue damage wound healing problems ,
wound infection, neurologic injury (about 7% in short to 40% in long stripping
of GSV) and lymphatic complications. To improve efficacy, patients* HRQOL, and
treatment satisfaction and to reduce serious side effects, costs, and
postoperative pain, new minimally invasive techniques, such as
ultrasound-guided foam sclerotherapy (UGFS), endovenous laser ablation (EVLA),
and radiofrequency ablation (RFA), have been introduced in the last decade.
The mechanism of ablation of the latter two therapies is based on heating (of
at least 85 degrees Celsius) of the venous structure including the creation of
intravascular *steam bubbles* either using laser emission or radiofrequency .
Advantageous of the endovascular procedures is that they can be performed under
local anesthesia with absence of wound infections or lymphatic complications
and lesser tissue damage as compared to the stripping procedure. The
initially suggested theoretical disadvantage of the absence of a crossectomie
in the endovascular procedures cannot be reproduced in clinical studies A
comparison between RFA and EVLA in a recent study shows similar results,
although the RFA scores significantly better regarding the postprocedural pain
and early recovery, which is allotted to the relatively low working
temperature.
A new minimally invasive endovenous therapy ha s been developed that generates
and administers high pressure steam in the varicose vein (i.e., Steam Ablation.
The theoretical advantages of this new procedure are the low working
temperature combined with very local and extremely efficient transmission of
thermal energy and (probably) by consequence the low tissue damage, and
possibly patient satisfaction. The steam generator is less expensive than
existing laser and radiofrequency devices and requires little to no
maintenance. In contrast to EVLA, RFA and UGFS, Steam Ablation uses sterile
water, which is natural body*s substance and has not the possible disadvantage
of inducing harm using or generating exogenous substances. (In comparison, the
EVLA procedure produces foreign material, during the procedure blood is
carbonized and also the laser tip seems to shrink or partially to evaporate).
Like in the VNUS catheter the temperature is fully regulated, the steam has a
constant temperature of no more than maximally 140°C. Because the induced
temperature rise is limited (in accordance with RFA), it is likely that the
treatment related symptoms (i.e., pain and bruising) and complication rate is
lower than EVLA, which may increase patient*s comfort and treatment safety. In
comparison to the RFA there is a sublime and more efficient transmission of
energy to the vessel wall: because of the pressure of the steam at 140 degrees
a full contact with the vessel wall is guaranteed. As a result of this contact
to the vessel wall the condensation of the steam takes place. It is during this
condensation process that the largest part of the transmitted energy is
released. (e.g. 1 gram steam produces 2260 J when it condensates into water and
only 260 J is produced by cooling from 100 to 37 degrees celsius) Moreover in
consequence of the pressure of the steam, blood is pushed out of the treated
segment of the vessel and therefore the collateral absorption of energy is
minimized.
In the RFA technique an outside compression of the vessel wall is needed to
optimize the transmission of thermal energy and to evacuate the blood from the
treated segment.

To test whether the anatomical success rate of Steam Ablation is not inferior
to that of VNUS in treatment of GSV insufficiency and compare the treatment
safety, patient reported outcomes between and Steam Ablation.

A non-inferiority randomized single blinded unicenter clinical trial with one
year follow up.

Study questions
I. Is Steam Ablation not inferior to RFA in occluding the insufficient GSV
after a follow-up period of one year?
II. Does Steam Ablation induce fewer (major and minor) complications than RFA?
III. Has Steam Ablation less impact on patients* lives the month following
therapy.
IV. Do patients experience a higher treatment satisfaction after Steam Ablation
than after RFA?
V. Is Steam Ablation cheaper than RFA?

1. Radiofrequency Ablation

RFA will be performed with the patient under local tumescent anesthesia in an
outpatient setting. Venous access is obtained by a puncture with a 19 G needle
under US guidance. Most commonly, the insufficient GSV is entered at knee level
because of ease of access and the smaller risk of nerve injury. A precut is
made under local anesthesia, introduction of an Medex easy glide, 7 french
introducer in the next sequence: puncture with 19 G needle, insertion of a
guide wire, insertion of the canula, removal of the guide wire. Insertion and
positioning of the RFA catheter and positioning of its tip. Position: tip of
the catheter is located 2cm distal of the saphenofemoral junction (SFJ).
Administration of the tumescent into the perivenous space under US guidance
using a mechanical infusion pump. Composition of tumescent fluid is 500 cc
NaCl 0,9, bicarbonate and lidocaine 400 mg. Tumescent anesthesia is warranted
because it reduces pain, cools perivenous tissue, and decreases the venous
diameter.
Radiofrequency waves are applied to the heating element in 20-second intervals
to sequentially heat and ablate the vein in seven centimeter increments. The
first segment, near the SFJ, is heated twice the 20 second interal. After each
segment is treated, the RFA catheter is manually withdrawn down the vein and
the process is repeated until the entire length of the vein has been ablated.
The ablated vein becomes scar tissue and is eventually absorbed by the body.
After the procedure patients are advised to wear medical elastic compression
stockings for 48 hours and to mobilize immediately.

2. Steam Ablation

The procedure of Steam Ablation is very similar to the radiofrequency
procedure. Steam Ablation will be performed with the patient under local
tumescent anesthesia in an outpatient setting. Venous access is obtained by a
puncture with a 19 G needle under US guidance. Most commonly, the insufficient
GSV is entered at knee level because of ease of access and the smaller risk of
nerve injury. After entrance to the varicose vein is established, the Steam
Ablation catheter (1.2 mm) is passed through
the hollow needle into the vein until it is positioned a few centimeters below
the junction. The most pivotal step in the Steam Ablation procedure is
positioning the echo-dense tip of the sheath approximately 2 cm distally from
the junction (under longitudinal US visualization). Tumescent is administered
for the same reason and with the same composition as in the RFA procedure.
After activation, the catheter will release small *puffs* of steam and the
catheter is pulled back stepwise. Every centimeter one puff of steam is
administered in veins <7 mm diameter, 2 puffs of steam in veins 7-10 mm and 3
puffs in veins >10 mm in diameter. So, the steam will be administered in a
pulsed manner. Approximately 2258 J is released when 1 g of steam is
condensated. In
order to occlude 30 cm of vein, theoretically 1 to 1.5 cc of water is needed.
In practice, 2 to 5 cc water will be needed, because not all steam will be
condensated at the vein wall. After the procedure patients are advised to wear
medical elastic compression stockings for 48 hours and to mobilize immediately.

not applicable