9 Endovenous Thermal Ablation of Incompetent Truncal Veins in Patients with Superficial Venous Insufficiency
Neil M. Khilnani and Robert J. Min
N. M. Khilnani, MD; R. J. Min, MD
Cornell Vascular, Weill Medical College of Cornell University, 416 East 55th Street, New York, NY 10022, USA
of patients with all forms of CVI have significant superficial venous insufficiency (SVI). If present, treatment of CVI begins with elimination of this reflux. Reflux in the saphenous (truncal) veins is the most common cause of venous hypertension. Patho- physiologically significant reflux in the great saphe- nous vein (GSV) or in one of its primary tributaries is present in 70%–80% of patients with CVI. Small saphenous vein (SSV) reflux is found in 10%–20%
and non-saphenous superficial reflux is identified in 10%–15% of patients [2, 3].
SVI is certainly the most prevalent medical con- dition treated by interventional radiologists. Up to 25% of women and 10% of men in the U.S. are affected, with 50% of people >50 years old having some form of SVI [3]. Most patients with SVI have symptoms, which include aching, fatigue, throb- bing, heaviness, and night cramps. A minority of patients develop skin injury from chronic venous hypertension, which includes eczema, edema, pig- mentation, lipodermatosclerosis, and ulceration.
Heredity is the primary risk factor for developing SVI; 85% of patients are affected if both parents are involved, 47% if one parent is involved, and 20% if neither parent is involved [4]. Prolonged standing and multiparity increase the risk of expressing this heritable risk.
9.3 Anatomy
The superficial venous system of the lower extremi- ties is composed of innumerable subcutaneous col- lecting veins, the saphenous trunks and their tribu- taries. The GSV begins on the anterior and medial portion of the foot, runs anterior to the medial mal- leolus, and ascends the medial aspect of the calf and thigh to ultimately join the femoral vein at the fossa ovale (saphenofemoral junction, SFJ) several centi- meters below the inguinal ligament (Fig. 9.1). The GSV is adjacent to the saphenous nerve (sensory)
CONTENTS
9.1 Introduction 119
9.2 Pathophysiology and Epidemiology 119 9.3 Anatomy 119
9.4 EVTA: Background 120 9.5 Evaluation Prior to EVTA 121 9.6 EVTA Technique 121 9.7 Clinical Data 123 9.8 Summary 125 References 125
9.1
Introduction
Endovenous thermal ablation has become an accepted option to eliminate the reflux caused by incompetent saphenous veins. In this chapter, a review of the clinical problems and anatomy pre- cedes a review of this exciting new venous occlusion technique.
9.2
Pathophysiology and Epidemiology
Lower-extremity chronic venous insufficiency (CVI)
is caused by venous hypertension [1]. Most patients
develop venous hypertension from the hydrostatic
forces produced by reflux that results from primary
valvular insufficiency [2] Venous obstruction, mus-
cular pump failure, and congenital anomalies are
much less common causes. In addition, 85%–90%
from about 6 cm below the knee to the ankle. The GSV and its major named branches run superficial to the deep and deep to the superficial fascia within the saphenous space. The GSV has two important and named tributaries above and below the knee:
the anterior and posterior circumflex veins of the calf and thigh. In addition there are three smaller tributaries at the groin which are important in that they are often a source of recurrent varicose veins following their surgical ligation along with the GSV (high ligation). A common variant, the anterior accessory GSV (AAGSV), runs more laterally than the GSV within the saphenous space and often is erroneously termed a duplication of this trunk. This vein is frequently present and can be responsible for varicose veins on the anterior aspect of the thigh.
An extrafascial tributary vein that communicates with the GSV but runs parallel to the GSV course and is relatively straight should be described as a superficial accessory GSV.
The SSV begins on the lateral aspect of the foot, ascends posterior to the lateral malleolus and then up the midline of the calf, between the same fascial planes as the GSV. The SSV runs adjacent to the sural nerve (sensory) from just below the popliteal crease to the foot. In about two thirds of cases, the SSV drains into the popliteal vein at or just above the popliteal crease. In about one third of cases it has a cephalad extension with or without a saphe- nopopliteal junction (SPJ) to ultimately drain into
a posterior thigh perforating vein, or into the pos- terior circumflex vein of the thigh via the vein of Giacomini (Fig. 9.1).
9.4
EVTA: Background
Treatment of SVI is indicated for symptoms unre- lieved by conservative methods such as graduated compression stockings (GCS), exercise, and avoid- ing prolonged standing. It is also indicated for com- plications from chronic venous hypertension such as bleeding varices, superficial thrombophlebitis, and skin injury. Treatment begins with elimina- tion of any truncal incompetence. The treatment modalities available to accomplish this include high ligation, truncal vein stripping along with a high ligation, endovenous thermal ablation (EVTA), and duplex ultrasound (DUS)-guided sclerotherapy.
In the last 5 years, EVTA has developed into a successful option for obliterating truncal incom- petence. Its main advantages over surgery are that there is no need for anesthesia or sedation and no recovery or down time following the procedure. The underlying mechanism of this procedure is to endo- vascularly deliver sufficient thermal energy to the wall of an incompetent vein segment to produce irre- versible occlusion. The first modern report of EVTA
Fig. 9.1. Frontal and posterior diagrams of the lower extremity demonstrating the great and small saphenous veins and their named tributaries. The two saphe- nous systems can be connected via the vein of Giacomini
was made using laser-delivered energy to ablate the saphenofemoral junction [6]. Since that time several devices have been approved by the U.S. Food and Drug Administration. The currently available tools utilize radiofrequency or laser energy of a variety of different wavelengths to deliver the required ther- mal dose.
As mentioned, the goal of EVTA is to endove- nously deliver sufficient thermal energy to the wall of an incompetent vein to irreversibly occlude it. A catheter inserted into the venous system either by percutaneous access or by open venotomy delivers the thermal energy. The procedure can be performed on an ambulatory basis with local anesthetic and generally require little or no sedation. The patients are generally fully ambulatory following treatment and the recovery time is short.
The associated varicose tributary and reticular veins and telangiectasias are treated separately with adjunctive therapies such as compression sclero- therapy or microphlebectomy. Some physicians will perform microphlebectomy for varicose veins at the same time as EVTA. Other physicians elect to perform phlebectomy or compression sclerotherapy of the varicose veins at a later time. Almost all phy- sicians will defer therapy of spider veins to a later time.
In our practice, phlebectomy is generally recom- mended at the same time as EVTA when varicose tributaries are larger than 8–10 mm in diameter or when EVTA will occlude their inflow and outflow.
If such veins are left untreated they may thrombose in 5%–10% of cases and become painful, erythem- atous, and possibly result in skin pigmentation.
Also, if they thrombose, their complete eradication may be made more difficult and certainly will be delayed. For smaller varicose veins and all reticular and spider veins, we offer compression sclerother- apy beginning 4 weeks after EVTA. By this point the veins have substantially decompressed, making their eradication with injections easier.
9.5
Evaluation Prior to EVTA
Treatment for patients with CVI begins with a care- ful history and directed physical exam. All patients with visible varicose veins or symptoms suggesting venous insufficiency should be evaluated with DUS [7, 8]. In patients with spider veins near the medial ankle (corona phlebectasia) or along the medial
calf or thigh, a DUS of the GSV is recommended to identify truncal reflux. The goal of the DUS is to determine which veins are normal and which veins are incompetent to create a map of the pathways of reflux in a given patient. Such a map is necessary to define the best combination of treatments which are available. In some cases, it may be possible to iden- tify the abnormal vein segments by physical exam.
However, the different pathways of incompetence overlap sufficiently such that reliance on physical examination alone will lead to frequent diagnostic errors.
Reflux in truncal veins must be treated prior to addressing any visible abnormalities. EVTA is a treatment option for endovenously eliminating such reflux. The indications for ablation of incompetent truncal veins are identical to those for surgical liga- tion and stripping. Absolute contraindications have yet to be identified for the laser procedure. For RF ablation, a pacemaker or implantable defibrillator is a contraindication. Relative contraindications for EVTA include absent pedal pulses limiting GCS use, liver abnormalities limiting local anesthesia use, pregnancy, nursing, and uncorrectable coagulopa- thies.
9.6
EVTA Technique
Once the pathways of incompetence are established, EVTA can be utilized to treat incompetent truncal veins and straight segments of their tributary veins.
In almost all cases venous access is directly into the vein to be treated or directly into one of its principle tributaries, if the tributary vein is straight. Gener- ally the access is at or just below the lowest level of reflux in the treated truncal vein as defined by DUS.
This is generally recognized as the level where the
diameter of the truncal vein decreases just periph-
eral to a large incompetent tributary. In many cases,
segmental great saphenous vein incompetence can
occur in two separate portions of this vein. The
reflux can completely spill out into a tributary vein
only to re-enter the GSV at a lower level. It is impor-
tant to determine if the intervening portion of the
GSV is hypoplastic or normal. Hypoplastic segments
occur commonly [9] and cannot be traversed by a
guidewire. In this circumstance, venous access will
be required into the most peripheral part of both
segments and the segments are subsequently ablated
sequentially. Normal intervening segments can be
crossed and allow the operator to treat all incom- petent segments of the GSV through one venous access.
Prior to treatment, the treated veins are mapped and the courses of the treated segments as well as important landmarks such as junctions, venous aneurysms and large perforator inflows are drawn on the patient’s skin with a surgical marker. The patient is then placed horizontal on the table allow- ing full access to the treated segments. In general, patients being treated for GSV reflux are placed supine. Patients being treated for reflux in the SSV are placed prone with their feet hanging off the end of the table to relax the calf. Posterior medial tribu- tary and Giacomini vein ablations may require more challenging positions.
Venous access is accomplished with either a 19- or 21-G needle using real-time US guidance and a one- wall technique. The incompetent truncal vein can become much smaller when the patient lies down.
Placing the patients in the reverse Trendelenburg position and keeping the procedure room warm can dilate the vein to make access easier. Also, when the puncture is directed into a tributary vein or the AAGSV, care must be taken to avoid venospasm, which is much more common with missed punc- tures of these veins.
The details of the laser and RF treatments vary at this point but the ultimate treatment goals and tech- niques are similar. With RF ablation, the RF cath- eter is withdrawn only after its tines are exposed to allow contact with the vein wall. The catheter is withdrawn maintaining the vein wall temperature at or above 85°C as measured by a thermocouple embedded in its tip. For laser ablation the fiber is withdrawn at a rate determined by the energy depo- sition per length of vein treated. For the remainder of this presentation on technique, the laser proce- dure will be discussed. The details of the RF venous ablation can be reviewed in the references cited in the results section.
For laser EVTA, a 5F sheath is inserted through the entire abnormal segment and into a more central vein. A bare tipped laser fiber is inserted to the end of the sheath, which is then withdrawn exposing the tip of the fiber. The sheath and fiber are then with- drawn to place the tip at the staring point of the abla- tion. For the GSV this is usually about 1 cm below the SFJ and for the SSV about 2 cm below the SPJ where the SSV turns parallel to the skin just below the popliteal fossa (Fig. 9.2). With the laser, confir- mation of the position can be made with localization of the light which comes from the red aiming beam
which can almost always be visualized through the skin.
The most time consuming part of the procedure is the US-guided delivery of perivenous tumescent anesthesia (TA). TA is a form of local anesthesia delivery which was popularized by plastic surgeons which utilizes large volumes of dilute anesthetic solutions which are infiltrated to anesthetize large regions for treatment. TA can make EVTA pain- less obviating the risks and additional monitoring associated sedation or anesthesia. In fact, it can be argued that sedation adds risk to EVTA by blunt- ing the patients’ response to pain making them potentially more susceptible to extravenous thermal injury as well as delaying immediate ambulation after the procedure.
TA is also necessary for safety and efficacy of the procedure as well. Large volumes are utilized to compress the truncal vein to maximize the transfer of energy to the surrounding vein wall. Even though venospasm frequently occurs soon after sheath inser- tion, it is usually still necessary to empty the vein further with TA to ensure adequate treatment. Also important is that the large volume of fluid around the vein is necessary to insulate the vein from the surrounding structures. This part of the procedure
Fig. 9.2. Longitudinal view of the saphenofemoral junction (SFJ) during positioning of a laser fi ber prior to EVTA. The left of the image is toward the patient’s head. A thin arrow points to the tip pf the laser fi ber approximately 5–10 mm below the SFJ at the takeoff of the superfi cial epigastic vein.
The (*) identifi es the SFJ, FV the femoral vein, GSV the great saphenous vein and SEG the superfi cial epigastric vein
minimizes potential thermal injury to the skin or adjacent nerves or arteries. In practice a 1-cm-diam- eter cylinder of TA surrounding the treated vein and 1 cm separation of the treated vein from the skin is adequate.
For EVTA, we generally use 100–200 ml of a 0.1%
lidocaine solution buffered with sodium bicarbon- ate. Utilizing these volumes we can get close to the 4.5-mg lidocaine/kg dose without epinephrine and 7-mg/kg doses with epinephrine. In plastic surgery these doses are routinely safely exceeded. The argu- ment for this safety is that the large volumes of fluid containing this drug are absorbed slowly avoid- ing high systemic levels. However, in an outpatient environment, it is best to avoid reaching these dose thresholds. In our practice, we also avoid the use of epinephrine to avoid any toxicity related to this drug.
After placing the patient in a Trendelenburg posi- tion to further empty the vein of blood, the sheath and fiber are withdrawn as a unit through the treated vein segment as the laser is activated. With DUS, gas bubbles can be seen to emanate from the tip of the laser fiber which serves as additional confirmation of the tip position at the appropriate location.
Suggested parameters vary slightly with the dif- ferent laser devices but are under the control of the operator. In our practice, using the 810-nm diode laser (Diomed, Andover, MA) 14-watt continuous mode is selected. The amount of energy necessary to effect reliable vein ablation seems to be an average of 80 J/cm throughout the treated segment [10]. The average pullback rate to accomplish this is about 2 mm/s. In practice for the GSV we generally pull back at 1 mm/s for the first 10 cm or so f treatment since failures, if they occur, will happen at this loca- tion. We also pull back at this rate near the inflow of incompetent perforators or pudendal veins or the take off of large incompetent tributaries to maximize successful occlusion at these important locations.
When treating the GSV or a superficial accessory saphenous vein when the vein is superficial, when treating the SSV or the GSV below Boyd’s perforator, we withdraw the fiber at 3 mm/s to minimize skin or nerve injuries.
Following the procedure, patients should be placed into a Class II (30–40 mmHg) graduated compression stocking (GCS) usually for 2 weeks.
The purpose of this is to keep the variceal tributar- ies as empty as possible in case they occlude to min- imize the amount of resultant thrombus. The GCS also increases the velocity of blood flow in the deep veins decreasing the likelihood of deep vein throm-
bosis. Anticoagulation with low-molecular-weight heparins is routinely used after EVTA in Europe but not in the US.
After EVTA, most patients will develop an ecchy- mosis over the entire treated segment. This gener- ally develops the day after the procedure but fades by about 2–3 weeks. Most patients will comment about some mild discomfort over the treated vein which begins hours after the procedure but resolves within 24–48 h. The GCS helps minimize this dis- comfort; some patients use acetaminophen with good response. With laser ablation, patients will also develop a discomfort over the vein about 7–10 days after the procedure, which is generally described as being similar to a pulled muscle. This is most likely caused by transverse and longitudinal retraction of the vein as the acute inflammation transitions to cicatrization. This resolves with movement, occa- sional NSAID use and continued use of the GCS. No further treatment has been necessary in our experi- ence.
Periodic follow-up DUS is suggested to monitor for the response to therapy. In general, at about 4 weeks following EVTA, one will identify a smaller- diameter, thick-walled truncal vein likely the result of significant vein wall injury and its inflammatory response. Little or no lumen or intraluminal throm- bus is typically identified and no flow will be found in the treated segment. By 6–12 months the vein will continue to shrink in size so that in successfully treated cases the vein can no longer be visualized [11–13]. If the vein shrinks to this extent further follow-up is probably not necessary.
Most patients will require adjunctive treatment of the branch varicosities. Compression sclerotherapy and micro-phlebectomy are the most commonly used techniques to accomplish this. Occasionally, deeper tributary veins may require DUS-guided sclerotherapy, and rarely, large variceal clusters will require conventional phlebectomy.
9.7
Clinical Data
The technical success of EVTA is defined as a pro-
cedure with successful access, crossing the segment
to be treated, delivery of tumescent anesthesia and
delivery of thermal energy to the entire incompe-
tent segment. Clinical success is defined as the per-
manent occlusion of the treated vein segments and
successful elimination of related varicose veins and
an improvement in the clinical classification of the patients by at least one grade at a certain time inter- val after the procedure. As previously mentioned, in practice most patients will also be treated with either adjunctive micro-phlebectomy or compres- sion sclerotherapy and as a result the clinical success data for the different clinical reports can be con- founded by the success of the adjunctive procedures and by enthusiasm by which they are utilized by the treating physician.
Duplex ultrasound is essential to document the permanent occlusion of truncal veins treated with EVTA [11–13]. A successful procedure will result in non-thrombotic circumferential vein wall injury from the highest level of the incompetent segment and through its treated course on early evaluation.
On late follow-up the vein segment will ideally be obliterated and impossible to find or at least will be significantly smaller in cross section than prior to treatment and will have no flow throughout the treated segment.
RF ablation was the first approved device for EVTA. Several single-center reviews have been pub- lished and are presented in Table 9.1. These stud- ies have consistently demonstrated a high degree of success in occluding the target vein. Complica- tion rates have been low, with paresthesias and skin burns being the most common and vexing problem with RF ablation. DVT is an uncommon problem in these series [19]. The imaging follow-up of these patients (median 25 months) has demonstrated truncal occlusion of the GSV in 90% with persistent patency without reflux of the SFJ in the overwhelm- ing majority of cases [12].
An industry-sponsored registry is being accu- mulated with published 2-year follow-up data [17].
The patients in this trial were selected to have GSV d12mm and without significant tortuosity. In this review 142 limbs were followed up at 2 years with DUS. Reflux was demonstrated absent in 90% with significant reductions in pain, fatigue and edema and 94.6% improvement in symptoms overall. There
were no cases of neovascularization. Complications were minor, with DVT in 0.7%, PE in 0.3%, skin burns in 4.2% of the early cases and 0% after the use of TA, and paresthesias persistent at 2 years in 5.6%
of patients (Table 9.1).
A single-center pilot randomized trial was per- formed early in the RF experience comparing pro- cedure related success and complications of ligation and stripping to RF EVTA of the GSV [20]. Fifteen patients were randomized to RF and 13 to surgery and all patients were followed for a mean of 50 days.
The technical and clinical success and complica- tion rates were similar. The RF technique was per- formed without tumescent anesthesia and many of the described complication would likely have been avoided with its utilization. Using a visual ana- logue pain scale, clear advantages were noted for EVTA most marked from days 5–14 following treat- ment. Less analgesics and days off from work were required by the EVTA group. Health related quality of life assessments ultimately improved to a similar extent but the EVTA group reached maximum ben- efit earlier.
Another small multi-center randomized trial comparing RF ablation to surgical stripping of the GSV with high ligation has been performed [21]. The data collected at a mean of 4-month follow-up and demonstrated that the recovery following RF abla- tion was shorter than following surgery with a sig- nificantly higher fraction of patients back to their usual level of activity at one day following the abla- tions. Of note was that the recovery was significantly quicker in those patients treated with RF ablation using only TA than in those treated with TA along with any other form of anesthesia. QOL as assessed using a standardized instrument was found to be significantly better immediately after RFA than after surgery, although by 4 months this difference was becoming significantly smaller.
Endovenous laser ablation of the great saphenous vein, short saphenous vein and other saphenous- related trunks has been approved by the FDA. The
Table 9.1. Clinical data evaluating the use of RF ablation of the GSV
Author Limbs Follow-up Success
(occluded vein/partly open, no reflux)
Parasthesias DVT Burns Ref #
Weiss 140 6 wks–2
years
96% 8% / 1% @ 6 mos. 0 0 14
Kistner 300 1 year 97% NR 0.7% 0.3% 15
Goldman 41 6–24 mos. 68%/22% 0 0 NR 16
Merchant (VNUS registry)
232@12 mos./
142@24 mos.
12–24 mos. 84%/6%@12 mos., 85%/4%@24 mos. 15%/6%@24 mos. 1% 2.1% 17
Wagner 24 3–12 mos. 21/21@3 mos. And 3/3 @ 12 mos. 0 1/24 0 18
reported success rates reported in several single- center series laser ablation for GSV are presented in Table 9.2. In these series there were no restrictions to vein size or degree of tortuosity. These data have consistently shown successful nonthrombotic occlu- sion of the target truncal vein in >90% of cases with very rare recanalizations of previously occluded vein segments. Clinical improvement was noted in almost all of the cases with successful truncal vein occlusion. The incidence of DVT, paresthesias and skin burns was almost 0% in these series. Most patients have bruising over the region treated prob- ably related to the needle injections for tumescent anesthesia. Many also describe a pulling sensation about 1 week after the procedure which is thought to be secondary to the evolution of the inflamma- tory response from vein wall injury maturing into a cicatrization phase. Superficial phlebitis was reported in 5–12% of patients after laser treatment noted primarily in cohorts of patients treated with delayed compression sclerotherapy rather than in those treated with immediate ambulatory phlebec- tomy of the larger tributary varicosities.
Optimization of the laser technique has prompted an evaluation of outcomes related to treatment parameters. Zimmett has suggested a lower rate of bruising and discomfort associate with continu- ous as opposed to pulsed laser energy delivery [27].
Timperman [10] has shown that the success of laser EVTA is unity when energy delivery is maintained on average as greater than 80 J/cm of vein treated.
Further optimization is likely to influence the out- come and side effects somewhat. However, given the high degree of success comparisons of large num- bers of patients will likely be necessary to establish any expected subtle difference.
Although speculation exits regarding differences between laser and RF EVTA success and side effects, there is no significant published experience com- paring these two technologies. The important thing to recognize is that both of these technologies rep- resent exciting, minimally invasive, low-risk, quick- recovery options for patients with symptoms or complications of superficial venous insufficiency.
Re-canalization of a treated vein presenting within the first few months after EVTA likely results from insufficient thermal energy delivery. This is either because of excessively rapid pull back of the thermal device or inadequate TA resulting in poor transfer of thermal energy to the wall. Vein diameter probably has no bearing on the success assuming adequate TA is applied, regardless of whether RFA or laser is the source of this energy. Late recurrences can be related to re-canalization of a previously occluded vein but are more likely related to development of incompe- tence in previously untreated vein segments.
9.8 Summary
EVTA should be considered a scientifically accept- able option to eliminate truncal reflux. The pro- cedures can be performed without sedation in an ambulatory setting and are very effective, safe and associated with virtually immediate recovery. EVTA appears to be associated with a lower rate of recur- rent SVI due to a virtual absence of the high rate of groin neovascularity seen with high ligation and stripping of the GSV. EVTA procedures have already begun to supplant traditional surgery for truncal incompetence.
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Author Limbs Follow-up Success Parasthesias DVT SVT Burns Ref #
Min 121 24 mos. 93% 0 0 NR 0 22
Proebstle (GSV) 104 12 mos. 90% 0 0 10% 0 23
Sadick 030 24 mos. 97% 0 0 0 0 24
Todd 291 12 mos. 96% NR NR NR NR 25
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