Prospective Evaluation of Higher Energy Great Saphenous Vein Endovenous Laser Treatment

Limitations of and Lessons Learned from Clinical Experience of 1,020 Duplex Arteriography

Objective: Due to the inherent risks, deficiencies and cost associated with contrast arteriography (CA), our group has been utitilizing duplex arteriography (DA) for evaluating the arteries of the lower extremity for patients undergoing lower extremity revascularization. In an effort to further explore the strengths and weaknesses of DA, we reviewed our evolving experience with DA from January 1, 1998, to January 1, 2005.

Patients and Methods: The arterial segments starting from mid-abdominal aorta to the pedal arteries were studied in cross-sectional and longitudinal planes using a variety of scanheads of 7–4, 10–5, 12–5, 5–2 and 3–2 MHz extended operative frequency range to obtain high-quality B-mode, color and power Doppler images as well as velocity spectra. In 906 patients, 1,020 duplex arteriograms were obtained. The ages ranged from 30–98 years old with a mean of 73±11 (SD) years. Fifty percent of the patients were diabetics. Indications for the examination included: tissue loss (409), rest pain (221), claudication (310), acute ischemia (74), popliteal aneurysm (45), SFA aneurysm (2), abdominal aortic aneurysms (AAA) (10) and failing bypass (55). Prior procedures had been performed in 262. DA was performed by six technologists (4 of whom are MDs). In all, 207 DA were performed intraoperatively and the remainder, preoperatively.

Results: The resultant procedures based upon DA included: bypass to the popliteal artery (262) and bypass to an infrapopliteal artery (325), endovascular procedures (363), thrombectomy (11), embolectomy (9), inflow bypass procedures to the femoral arteries (46), débridment (4), amputation (8) and no intervention (75). The areas not visualized well included: iliac (73), femoral (26), popliteal (17), and infrapopliteal (221). Additional imaging after DA was deemed necessary in 102 cases to obtain enough information to plan lower extremity revascularization. Factors associated with increased need to obtain CA included: DM ( p<.001), infrapopliteal calcification ( p<.001), older age ( p = .01) and limb threatening ischemia ( p<.001). Factors not associated with the need to obtain CA included: which technologist performed the exam, whether the technologist has a medical degree and whether the patient underwent prior revascularization.

Conclusions: In 90% of patients reviewed, DA is able to obtain the needed information to plan lower extremity revascularization. Severe tibial vessel calcification is the most common cause of an incomplete DA exam and determines when alternative imaging modalities need to be obtained.

Endovenous Laser Treatment of Saphenous Vein Reflux: How Much Energy Do We Need to Prevent Recanalizations?

The aim of this study was to report the results of high-energy endovenous laser treatment to measure the relationship between the fluence and the outcome in terms of recanalization. In 97 patients, 129 great saphenous veins were treated with endovenous laser treatment, using a 980-nm diode laser. Follow-up visits were done at 3 days, 1 month, and 6 months. The best results were noted 1 month postoperative, but at 6 months, control late recanalizations occured decreasing occlusion rate to 90.6%. Patients were divided into 2 groups according to the outcome (occlusion or recanalization) at 6 months, and statistical analysis was done. The authors found 52 J/cm2 mean fluence in the occlusion group and 43.7 J/cm2 in the nonocclusion group. This was a statistical significant difference ( P < .01). The occlusion rate on long term is fluence dependent. But recanalizations might occur even in these higher fluence treatment groups. A fluence of 52J/cm2 is advised.

Endovenous laser ablation of varicose veins: review of current technologies and clinical outcome

Symptomatic lower extremity varicose veins represent one of the most common vascular conditions in the adult population. Associated symptoms ranged from mild conditions such as fatigue, heaviness, and itching to more serious conditions such as skin discoloration and leg ulceration. The predominant causative factor of this condition is reflux of the great saphenous vein (GSV), which is traditionally treated with surgical saphenofemoral ligation and stripping of the incompetent saphenous vein. In recent years, there have been significant advances in saphenous vein ablation using percutaneous techniques, including the endovenous laser therapy (EVLT). In this article, the authors discuss the therapeutic evolution of this technology, theoretical basis of laser energy in GSV ablation, and procedural techniques of EVLT using duplex ultrasonography. Additional discussion of procedural-related complications, such as deep vein thrombosis, skin burn, saphenous nerve injury, and phletibis, and ecchymosis, are provided. Lastly, clinical results of EVLT in GSV ablation are discussed. Current literatures support EVLT as a safe and effective treatment option for varicosities caused by GSV incompetence.

Effectiveness of endovenous laser treatment in eliminating superficial venous reflux

Objective

To describe a protocol for endovenous laser treatment that is highly effective, has no significant complications, and is well accepted by patients. This is the first published report that designates complete absence of the treated vein as the definition of a successful endovenous laser treatment.

Methods

A retrospective review of 516 endovenous laser treatments performed by a single physician in private medical practice over a 69-month period. Follow-up ranged from 3 to 65 months. All treatments were performed utilizing 810 nm laser energy (Diomed, Inc.). Periodic duplex ultrasound examinations were performed until the treated vein was absent. Surveys were done to assess post treatment pain and to evaluate the effect of treatment on quality of life.

Results

The described protocol for endovenous laser treatment has successfully eliminated 98.1% of 516 treated veins with a single laser treatment. Additionally, in the last 386 treated veins when increased energy levels were utilized, the success rate was 99.7%. There were no significant complications. Patient satisfaction with the procedure is extremely high.

Conclusions

Endovenous laser treatment is a highly effective procedure for eliminating superficial venous reflux in varicose veins selected for treatment when sufficient 810 nm (Diomed, Inc.) laser energy is utilized.

Technical review of endovenous laser therapy for varicose veins

BACKGROUND

In the last decade, several new treatments of truncal varicose veins have been introduced. Of these new therapies, endovenous laser therapy (EVLT) is one of the most widely accepted and used treatment options for incompetent greater and lesser saphenous veins.

OBJECTIVE

The objective of this report is to inform clinicians about the EVLT procedure and to review its efficacy and safety in treatment of truncal varicose veins. Also, we discuss some of the underlying theoretical principles and laser parameters that affect EVLT.

METHODS

We carried out a literature review of EVLT;s efficacy and safety. We included reports that included 100 or more limbs with a follow-up of at least 3 months. The principals and procedure of EVLT are described. Of the laser parameters, mode of administration, wavelength, fluence, wattage and pullback speed are discussed.

CONCLUSION

EVLT appears to be a very effective and safe option in the treatment of varicose veins but large randomized comparative studies are needed.

Standardisation of Parameters during Endovenous Laser Therapy of Truncal Varicose Veins - Experimental Ex-vivo Study

BACKGROUND

Vein shrinkage is a surrogate marker for successful laser treatment of varicose veins. However, many controversies still remain concerning the best laser parameters to use. The aim of this study was standardisation of intraoperative energy dosages and pull-back rates to achieve optimal clinical results.

DESIGN

Ex-vivo study in surgically removed saphenous trunks.

MATERIAL AND METHODS

Great saphenous veins were removed by Babcock stripping and irradiated with laser energy delivered by a laser diode emitting at 980 nm. In total, 279 vein segments (5 cm long) were treated using powers from 5-15 W. Vein segments were opened longitudinally and the circumference measured in the treated and untreated regions to assess thermal shrinkage.

RESULTS

The greatest shrinkage and minimum number of perforations was achieved using lower or medium power (8 to 12 W) with longer exposure to administer laser energy. The median percentage vein shrinkage was 50% (power 5 W), 45% (8 W), 40% (10 W), 45% (12 W) and 59% (15 W). When a higher power was used (15 W), the perforations were more frequent and carbonisation was marked.

CONCLUSIONS

Our data suggests that similar efficacy with fewer vein perforations may be obtained with low or medium power settings and increased exposure when undertaking laser obliteration of saphenous trunks. This may result in fewer adverse events such as ecchymosis following treatment in patients.

Mathematical modeling of 980-nm and 1320-nm endovenous laser treatment

BACKGROUND AND OBJECTIVES

Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins.

STUDY DESIGN/MATERIALS AND METHODS

The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature.

RESULTS

Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz).

DISCUSSION AND CONCLUSION

Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810-1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT.

Preprocedural imaging: new options to reduce need for contrast angiography

In vascular surgery, the gold standard for evaluation of the lower-extremity arterial tree has long been contrast arteriography (CA). Associated risks of CA are well-documented and include severe allergic reactions, arterial injury and/or hemorrhage, and contrast-induced nephropathy. Increasingly, less-invasive techniques, with fewer inherent risks for complication, are being explored as diagnostic alternatives. Magnetic resonance angiography, computed tomography angiography, and duplex arteriography, each offer distinct advantages, though are not without limitation. This review explores the indications, advantages, and disadvantages of these newer technologies and provides a comparison to CA as a means for defining the anatomic features of patients undergoing lower-extremity revascularization. This data suggests that noninvasive imaging technologies may, in the future, play an increasingly important role in the surgical evaluation of the patient with lower-extremity ischemia.

The treatment of varicose veins

INTRODUCTION

Over the past few years, there has been a move to less invasive endoluminal methods in the treatment of lower limb varicose veins combined with a renewed interest in sclerotherapy, with the recent addition of foam sclerotherapy. The development of these new techniques has led many to question some of the more conventional teaching on the treatment of varicose veins. This review examines these new treatments for lower limb varicose veins and the current evidence for their use.

MATERIALS AND METHODS

An extensive search of available electronic and paper-based databases was performed to identify studies relevant to the treatment of varicose veins with particular emphasis on those published within the last 10 years. These were analysed by both reviewers independently.

RESULTS

There is no single method of treatment appropriate for all cases. Conventional surgery is safe and effective and is still widely practised. Whilst the new treatments may be popular with both surgeons and patients, it is important that they are carefully evaluated not only for their clinical benefits and complications when compared to existing treatments but also for their cost prior to their wider acceptance into clinical practice.

Radiofrequency ablation and laser ablation in the treatment of varicose veins

Chronic venous insufficiency is a major medical disease in the United States. With a total population of 300 million, it is estimated that 25 million persons in this country alone have symptoms of this disease (1 in 12). Great saphenous vein reflux is the most common form of venous insufficiency in symptomatic patients and is most frequently responsible for varicose veins of the lower extremity. Therefore, therapy directed toward correcting superficial venous pathology is beneficial to many patients.

Reduced recanalization rates of the great saphenous vein after endovenous laser treatment with increased energy dosing: Definition of a threshold for the endovenous fluence equivalent

BACKGROUND

Recent reports indicated a correlation between the amount of energy released during endovenous laser treatment (ELT) of the great saphenous vein (GSV) and the success and durability of the procedure. Our objective was to analyze the influence of increased energy dosing on immediate occlusion and recanalization rates after ELT of the GSV.

METHODS

GSVs were treated with either 15 or 30 W of laser power by using a 940-nm diode laser with continuous fiber pullback and tumescent local anesthesia. Patients were followed up prospectively with duplex ultrasonography at day 1 and at 1, 3, 6, and 12 months.

RESULTS

A total of 114 GSVs were treated with 15 W, and 149 GSVs were treated with 30 W. The average endovenous fluence equivalents were 12.8 +/- 5.1 J/cm2 and 35.1 +/- 15.6 J/cm2, respectively. GSV occlusion rates according to the method of Kaplan and Meier for the 15- and 30-W groups were 95.6% and 100%, respectively, at day 1, 90.4% and 100% at 3 months, and 82.7% and 97.0% at 12 months after ELT (log-rank; P = .001). An endovenous fluence equivalent exceeding 20 J/cm2 was associated with durable GSV occlusion after 12 months' follow-up, thus suggesting a schedule for dosing of laser energy with respect to the vein diameter.

CONCLUSIONS

Higher dosing of laser energy shows a 100% immediate success rate and a significantly reduced recanalization rate during 12 months' follow-up.

Endovenous Laser Ablation of the Great Saphenous Vein with a 980-nm Diode Laser in Continuous Mode: Early Treatment Failures and Successful Repeat Treatments

PURPOSE

To investigate the efficacy of lower-energy endovenous laser treatment for great saphenous vein (GSV) incompetence and treatment parameters associated with early treatment failure.

MATERIALS AND METHODS

Sixty consecutive endovenous laser treatments (32 left, 28 right; 57 initial treatments, three repeat treatments) in 48 patients (13 men, 35 women; mean age, 55.2 +/- 12.9 years), with bilateral treatments in nine patients, were studied. Preprocedural clinical signs, etiology, anatomy, and physiologic classifications demonstrated class 2 limbs in 11.7% of cases, class 3 limbs in 25.0%, class 4 limbs in 48.3%, and class 5 limbs in 15.0%. All initial and repeat treatments were performed with lower-energy with use of a 980-nm diode endovenous laser at 11 W in continuous mode. Patients wore class II compression stockings for 2 weeks and were followed up at 1, 3, and 6 months with clinical and duplex ultrasound examinations. Treatment failures were diagnosed at 3 months on the basis of GSV patency or lack of clinical improvement. Diameter and length of GSV treated, treatment energy parameters, and clinical outcomes were prospectively measured and compared between successful and failed treatments.

RESULTS

The initial treatment success rate was 94.7% (54 of 57). The mean maximum diameter of successfully treated GSVs was 1.12 +/- 0.52 cm, and the mean maximum diameter of GSVs in which treatment failure occurred was 2.05 +/- 0.23 cm (P = .008). Mean total energy applied for successful treatments was 1,131.3 +/- 248.1 J, and mean total energy applied for failed treatments was 1,439.6 +/- 425.0 J (P = 0.053). Mean unit energy applied for successful treatments was 32.7 +/- 7.5 J/cm, and that for failed treatments was 32.8 +/- 4.9 J/cm (P = .986). All patients in whom treatment failed were successfully treated again with a mean total energy of 1,393.0 +/- 81.0 J and a mean unit energy of 29.4 +/- 4.9 J/cm. There were no significant differences in mean total energy or unit energy applied among successful, failed, and repeat treatments (P > .05). Mean follow-up duration was 6.8 months.

CONCLUSIONS

Endovenous laser treatment with lower energy appears to be safe and effective. Larger GSV diameter is associated with early treatment failures.

Treatment of varicose veins by endovenous laser therapy: assessment of results by ultrasound surveillance

OBJECTIVE

To assess the efficacy of endovenous laser therapy (EVLT) for treating varicose veins with saphenous reflux.

DESIGN

A trial of treatment, with results assessed by ultrasound surveillance.

SETTING

Outpatient clinics with sonographer and nursing support.

MAIN OUTCOME MEASURES

Control of reflux; occlusion or obliteration of the saphenous veins assessed by ultrasound.

RESULTS

EVLT was used to treat 404 veins in 308 patients. Univariate life table analysis showed primary success in 80% (95% CI, 69%-87%) and secondary success after further treatment of recurrent saphenous vein reflux by ultrasound-guided sclerotherapy in 88% (95% CI, 78%-95%) at 3 years. On multivariate Cox regression analysis, none of the covariates studied were associated with ultrasound failure.

CONCLUSIONS

Early results indicate that EVLT effectively controlled saphenous reflux. Its advantages are that it is performed as an outpatient procedure under local anaesthesia with immediate mobilisation, causes minimal disruption of activities, and avoids surgical trauma.

Mathematical modeling of endovenous laser treatment (ELT)

Background and objectives

Endovenous laser treatment (ELT) has been recently proposed as an alternative in the treatment of reflux of the Great Saphenous Vein (GSV) and Small Saphenous Vein (SSV). Successful ELT depends on the selection of optimal parameters required to achieve an optimal vein damage while avoiding side effects. Mathematical modeling of ELT could provide a better understanding of the ELT process and could determine the optimal dosage as a function of vein diameter.

Study design/materials and methods

The model is based on calculations describing the light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma Inc., Arlington, MA, USA). Damage to the vein wall for CW and single shot energy was calculated for 3 and 5 mm vein diameters. In pulsed mode, the pullback distance (3, 5 and 7 mm) was considered. For CW mode simulation, the pullback speed (1, 2, 3 mm/s) was the variable. The total dose was expressed as joules per centimeter in order to perform comparison to results already reported in clinical studies.

Results

In pulsed mode, for a 3 mm vein diameter, irrespective of the pullback distance (2, 5 or 7 mm), a minimum fluence of 15 J/cm is required to obtain a permanent damage of the intima. For a 5 mm vein diameter, 50 J/cm (15W-2s) is required. In continuous mode, for a 3 mm and 5 mm vein diameter, respectively 65 J/cm and 100 J/cm are required to obtain a permanent damage of the vessel wall. Finally, the use of different wavelengths (810 nm or 980 nm) played only a minor influence on these results.

Discussion and conclusion

The parameters determined by mathematical modeling are in agreement with those used in clinical practice. They confirm that thermal damage of the inner vein wall (tunica intima) is required to achieve the tissue alterations necessary in order to lead the vein to permanent occlusion. However, in order to obtain a high rate of success without adverse events, the knowledge of the vein diameter after tumescent anesthesia is recommended in order to use the optimal energy. As clearly demonstrated by our calculations, both pulsed and continuous mode operations of the laser can be efficient. An interesting observation in our model is that less amount of energy is required in pulsed mode than in continuous mode. Damaging the vein sequentially along its entire length may lead to permanent occlusion. However, the pulsed mode requires a very precise positioning of the fiber after each pullback and the duration of the treatment is much longer. For these reasons, continuous irradiation seems to be preferred by most clinicians. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT