Endovenous Laser Surgery of the Incompetent Greater Saphenous Vein With a 980-nm Diode Laser

Foaming of blood in endovenous laser treatment

This work is dedicated to a challenging issue of modern phlebology-establishment of a physical mechanism of the endovenous laser treatment (EVLT) against great saphenous vein incompetence (protuberant varicosities). Using optical and acoustical methods, we have studied the laser-induced formation of microbubbles in an aqueous solution of surface-active substances, serum, and blood directly in patients while conducting EVLT of the great saphenous vein in a clinical setting. We have used lasers with wavelengths 0.97 and 1.47 μm. Their radiation was transmitted through a quartz-quartz polymer fiber 600 μm in diameter. It has been found that in all cases, the laser beam with moderate power (1-10 W) supplied through an optical fiber leads to the formation of micro-bubbled foam. It has been shown that laser exposure during EVLT induces blood boiling, which results in heating of the venous walls (thermal destruction of the intima) and provides effective foam occlusion of the blood vessels (hemostasis). Necessary and sufficient conditions for a successful EVLT are associated with the thermal destruction of intima and laser-induced foam hemostasis.

Endovenous laser ablation of the great saphenous vein versus high ligation: long-term results

Endovenous laser therapy (EVLT) for greater saphenous vein (GSV) insufficiency is a relatively new method of treatment only recently made available in Iran. This is the first long-term randomized trial comparing EVLT with high ligation of saphenous vein (HLS) in the Iranian population. Sixty-five patients met the inclusion criteria and were divided into homogenous treatment groups of EVLT (n = 30) or HLS (n = 35). Clinical severity, etiology, anatomy, pathophysiology (CEAP) classification and Aberdeen Varicose Vein Symptom Severity Scores (AVSS) were used to determine disease severity and symptoms before and after the procedure in both groups. Outcome was measured by the rate of recurrence as shown in Doppler ultrasonography evaluation. Follow-up was conducted 1 week and 3, 6, 12, and 18 months after the intervention. The occlusion rate of GSV was similar in both groups (93.6% for EVLT, 88.3 for HLS) at 18 months of follow-up. The median CEAP score showed a dramatic decrease in both groups after 1 week which was sustained for the rest of the study. The Aberdeen Varicose Vein Symptom Severity score was significantly lower in the EVLT group at 12 and 18 months of follow-up. There was no significant difference in patient satisfaction in both groups. Our findings show that EVLT may offer a better long-term relief of symptoms. This, alongside its better cosmetic outcome, and less invasive anesthesia requirements may make it the favorable choice for treatment of GSV insufficiency.

Endovenous laser treatment (EVLT) for the saphenous reflux and varicose veins: a follow-up study

PURPOSE

The aim of this study is to report our experience about endovenous laser treatment (EVLT) for lower extremity varices in our centre which was followed by ultrasonography during the 6-month period.

METHODS

During a 1-year period, 46 patients who were treated by EVLT with the 940-nm diode laser for venous insufficiency enrolled in the study. The diagnosis of greater saphenous vein (GSV) incompetence with reflux was made by clinical evaluation and duplex Doppler examinations. Clinical outcomes, complications and duplex ultrasound of the GSV were assessed within 1 week, 1 month, 3 months and 6 months, after the endovascular laser treatment.

RESULTS

The mean age of our patients was 44 ± 11 years (24-70), and among them, 23 (50%) were male. Improvement in visible varicosity was seen in 39 (84.8%) patients after 6 months (P value = 0.011). The baseline mean diameter of GSV was 4.9 ± 1.6 mm and it dropped to 3.5 ± 1.3 after 6 months (P < 0.0001). After 6 months, 95.7% of our patients were satisfied and recommended this procedure to others.

CONCLUSIONS

Endovascular laser ablation seems to be a safe and effective method for the treatment of lower limb varices.

Numerical simulation of endovenous laser treatment of the incompetent great saphenous vein with external air cooling

Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein. Before the procedure, peri-saphenous subcutaneous tumescent saline solution infiltration is usually performed. However, diffusion of this tumescent fluid is rapidly observed and can potentially reduce the efficacy as a heat sink. External skin cooling with cold air was proposed as an alternative solution. The objective of this study is to compare endovenous laser treatment without and with air cooling by realistic numerical simulations. An optical-thermal damage model was formulated and implemented using finite element modeling. The general model simulated light distribution using the diffusion approximation of the transport theory, temperature rise using the bioheat equation, and laser-induced injury using the Arrhenius damage model. Parameters, used in clinical procedures, were considered: power, 15 W; pulse duration, 1 s; fiber pull back, 3-mm increments every second; cold air applied in continuous mode during ELT; and no tumescent anesthesia. Simulations were performed for vein locations at 5, 10, and 15 mm in depth, with and without air cooling. For a vein located at 15 mm in depth, no significant difference was observed with and without cooling. For a vein located at 10 mm in depth, surface temperature increase up to 45 °C is observed without cooling. For a vein located at 5 mm, without cooling, temperature increase leads to irreversible damage of dermis and epidermis. Conversely, with air cooling, surface temperature reaches a maximum of 38 °C in accordance with recordings performed on patients. ELT of the incompetent great saphenous vein with external air cooling system is a promising therapy technique. Use of cold air on the skin continuously flowing in the area of laser shot decreased significantly the heat extent and the thermal damage in the perivenous tissues and the skin.

A high-throughput comparative characterization of laser-induced soft tissue damage using 3D digital microscopy

3D digital microscopy was used to develop a rapid alternative approach to quantify the effects of specific laser parameters on soft tissue ablation and charring in vitro without the use of conventional tissue processing techniques. Two diode lasers operating at 810 and 980 nm wavelengths were used to ablate three tissue types (bovine liver, turkey breast, and bovine muscle) at varying laser power (0.3, 1.0, and 2.0 W) and velocities (1-50 mm/s). Spectrophotometric analyses were performed on each tissue to determine tissue-specific absorption coefficients and were considered in creating wavelength-dependent energy attenuation models to evaluate minimum heat of tissue ablations. 3D surface contour profiles characterizing tissue damage revealed that ablation depth and tissue charring increased with laser power and decreased with lateral velocity independent of wavelength and tissue type. While bovine liver ablation and charring were statistically higher at 810 than 980 nm (p < 0.05), turkey breast and bovine muscle ablated and charred more at 980 than 810 nm (p < 0.05). Spectrophotometric analysis revealed that bovine liver tissue had a greater tissue-specific absorption coefficient at 810 than 980 nm, while turkey breast and bovine muscle had a larger absorption coefficient at 980 nm (p < 0.05). This rapid 3D microscopic analysis of robot-driven laser ablation yielded highly reproducible data that supported well-defined trends related to laser-tissue interactions and enabled high throughput characterization of many laser-tissue permutations. Since 3D microscopy quantifies entire lesions without altering the tissue specimens, conventional and immunohistologic techniques can be used, if desired, to further interrogate specific sections of the digitized lesions.

Endovenous laser ablation: a review of mechanisms of action

BACKGROUND

The aim of this article is to summarize and review the proposed theories on the laser action during endovenous ablation.

METHODS

Laser mechanics and laser-tissue interaction are summarized from articles found in literature. Several theories, like the "steam bubble theory," the "direct contact theory," the "heat pipe," and "direct light energy absorption" are discussed.

RESULTS

The laser light emitted intraluminally can be absorbed, scattered, or reflected. Reflection is negligible in the near-infrared spectrum. By combining absorption and scattering, the optical extinction of different wavelengths related to different biological tissues can be determined. The direct contact of the fiber tip and the vein wall may be a way of destroying the vein wall, but results in ulcerations and perforations of the vein wall. Avoiding this contact, and allowing direct light absorption into the vein wall, results in a more homogenous vein wall destruction. If the energy is mainly absorbed by the intraluminal blood, the laser fiber will act as a heat pipe. Histological studies show that a more circumferential vein wall destruction can be obtained when the vein is emptied of its intraluminal blood. The use of tumescent liquid reinforces spasm of the vein and protects the perivenous tissue.

CONCLUSION

Several factors play an important role in the mechanism of endovenous laser ablation. Direct energy absorption by the vein wall is the most efficient mechanism. It is important to empty the vein of its intraluminal blood and to inject tumescent liquid around the vein.

Laser saphenous ablations in more than 1,000 limbs with long-term duplex examination follow-up

BACKGROUND

The goal of this study was to evaluate the duplex results of endovenous laser ablation in the treatment of incompetent great saphenous veins (GSV) and small saphenous veins (SSV) with at least 1-year follow-up.

METHODS

A retrospective registry was entered by 11 centers from Europe and America, organized by the International Endovenous Laser Working Group. Data concerning 1,020 limbs in patients with incompetence of the GSV and/or SSV, treated with the Endovenous Laser Ablation (EVLA) procedure, were collected. EVLA failures were defined on duplex imaging as reflux confined to the saphenofemoral or saphenopopliteal junction, reflux confined to the main saphenous trunk, or reflux of both junction and main trunk (totally patent saphenous vein) were analyzed at one or more years postoperatively.

RESULTS

The mean age of patients was 54 ± 5 years (range: 18-91 years). The average body mass index was 25. There was a paucity of severe complications: One case of third-degree skin burn, six patients with postsurgical deep vein thrombosis (0.6%), and 27 cases of sensory nerve damage (2.7%). At 1-year, the rate of complete occlusion of the saphenous trunk was 93.1%. There were 79 cases of treatment failures as evidenced by duplex: 22 isolated junction failures (2.2%), 44 isolated trunk failures (4.4%), and 13 totally patent veins (1.3%). Two-year duplex results were reported for 329 limbs with the identification of 19 new cases of failure. No new cases of failure were reported at 3-year follow-up of 130 limbs. Cumulative failure rates estimated by Kaplan-Meier analysis were 7.7% at 1-year and 13.1% at 2- and 3-year follow-up.

CONCLUSIONS

On the basis of a duplex scan performed at least 1-year post-treatment, this multicenter registry confirms the safety and efficacy of the EVLA procedure in the treatment of GSV and SSV reflux. Considering the continued failure rate documented in the present study, an annual follow-up by duplex is recommended to 2 years after EVLA.

Surgical management of varicose veins: meta-analysis

Open surgery remains the gold standard by which endovascular treatment of superficial chronic venous insufficiency is measured. This meta-analysis of randomized controlled trials reviews the current evidence base, comparing open and endovascular treatment of varicose veins. Systematic review of studies reporting duplex scan follow-up after open surgical, laser (endovenous laser therapy [EVLT]), or radiofrequency (VNUS Closure device, VNUS Medical Technologies, San Jose, CA) treatment of refluxing great saphenous veins was completed. Primary outcome measures were occlusion and complication rates and time taken to resume work. No significant difference in recurrence rates at 3 months between open surgery and EVLT (RR 2.19, 95% CI 0.99-4.85, p = .05) or VNUS device (RR 7.57; 95% CI 0.42-136.02) were found. Return to work is significantly faster following VNUS (by 8.24 days; 95% CI 10.50-5.97) or EVLT (by 5.02 days; 95% CI 6.52-3.52). Endovascular treatment of varicose veins is safe and effective and offers the significant advantage of rapid recovery.

Outcomes using a 1470-nm laser for symptomatic varicose veins

PURPOSE

The aim of this study was to evaluate safety and effectiveness of the laser fiber with wavelength of 1470 nm for ablation of symptomatic varicose veins.

MATERIALS AND METHODS

This was a prospective study carried out from November 2007 to October 2009. Seventy-six limbs in 72 consecutive patients were treated by endovenous laser ablation (EVLA). Baseline preprocedural clinical and ultrasonic grading of varicose veins was done. Endovenous laser ablation was done under ultrasonic guidance, and prior superficial venogram was taken if required. After the procedure all the patients were followed up with for 1 year with duplex ultrasound scan, and improvement in grading of venous disease was assessed.

RESULTS

One hundred eight treated veins of 76 limbs were followed up on day 2, 1 month, 6 month, and 12 months postprocedurally. At the end of 1-year follow-up, venous occlusion rate and ulcer healing rate were 98.61% and 85%, respectively. The average preoprocedure clinical grade and venous disability score improved significantly at 12 months. Most of the postprocedure complications were transient and self limiting; the most common complication was paresthesia (10.53%). No major complications, such as deep vein thrombosis, occurred. When the authors compared legs treated with linear endovenous energy density below or above 100 J/cm, the paresthesia rate and postoperative pain was significantly higher in the second group, with energy density more than 100 J/cm.

CONCLUSIONS

EVLA, using 1470-nm laser, is a minimally invasive, safe, outpatient department (OPD) procedure that causes less postprocedural pain with linear endovenous energy density (LEED) less than 100J/cm.

Comparison of Endovenous Laser Treatment for Varicose Veins with High Ligation Using Pulse Mode and without High Ligation Using Continuous Mode and Lower Energy

PURPOSE

To compare two methods of endovenous laser treatment (EVLT) for primary varicose veins of lower extremities: first-EVLT combined with high ligation of great saphenous vein using pulse mode ablation and 12 W laser ; second-EVLT without high ligation and using lower energy (10 W) and continuous mode.

MATERIALS AND METHODS

Ninety-three limbs of 75 patients were treated by 980 nm diode laser into the great saphenous veins from June, 2003. In the first group of 45 patients, (HL group), we performed a division of the sapheno-femoral junction after high ligation and EVLT was done with a 12 W laser in a pulse mode. In the second group of 30 patients (NL group) EVLT was performed without high ligation with a 10 W laser in a continuous mode using a laser fiber drawing device.

RESULTS

Operation time was significantly shorter in the NL group compared to the HL group (p < 0.05), and the early occlusion rates were 100% (HL group) and 97% (NL group). Subcutaneous bleeding occurred in 9 limbs (16%) in the HL group and 2 limbs (6%) in the NL group. In the NL group there was one case complicated with thrombus which extended into the femoral vein.

CONCLUSION

High ligation at sapheno-femoral junction is not necessary for EVLT and a lower energy continuous mode laser induces a lower rate of complications compared with a pulse mode ablation at a higher energy level. However, close follow-up with duplex scanning is necessary in early postoperative period.

Endovenous laser ablation: mechanism of action

Objectives

The objective of this study is to review the basics of laser and established tissue response patterns to thermal injury, with specific reference to endovenous laser ablation (EVLA). This study also reviews the current theories and supporting aspects for the mechanism of action of EVLA in the treatment of superficial venous reflux.

Methods

The method involves the review of published literature and original investigation of histological effects of 810 nm and 980 nm wavelength EVLA on explanted blood-filled bovine saphenous vein in an in vitro system.

Results

The existing histological reports confirm that EVLA produces a transmural vein wall injury, typically associated with perforations and carbonization. The pattern of injury is eccentrically distributed, with maximum injury occurring along the path of laser contact. Intravenous temperature monitoring studies during EVLA have confirmed that the peak temperatures at the fibre tip exceed 1000°C, and continuous temperatures of at least 300°C are maintained in the firing zone for the majority of the procedure. Steam production during EVLA, which occurs early in the photothermolytic process when temperatures reach 100°C, accounts for only 2% of applied energy dose, and is therefore unlikely to be the primary mechanism of action of thermal injury during the procedure.

Conclusion

EVLA causes permanent vein closure through a high-temperature photothermolytic process at the point of contact between the vein and the laser.

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.

Endovenous laser ablation of varicose veins after direct percutaneous puncture: early results

BACKGROUND

Although endovenous laser ablation has been demonstrated to effectively occlude incompetent saphenous veins, it does not treat branch varicosities directly.

OBJECTIVE

The objective was to evaluate the technical feasibility and early results of the direct ablation of branch varicosities using a 980-nm diode laser.

MATERIALS AND METHODS

From July to August 2005, 17 patients (21 limbs; male:female ratio, 7:10; mean age, 50.1 years; range, 24-62 years) with varicose veins were enrolled in this study. Endovenous laser ablation was performed in incompetent saphenous veins. Thereafter, branch varicosities were percutaneously punctured and a direct laser ablation was performed using a 400-microm laser fiber. Patients were evaluated at 1 week and at 1-, 3-, and 6-month intervals.

RESULTS

Technical success in branch varicosities was achieved in 11 of 15 limbs (71.4%). Continued closure of treated saphenous veins was evident in 11 of 11 limbs (100%) at 1-month follow-up. Successful ablation in varicose tributaries was seen in 6 of 11 limbs (54.5%) at 1-month follow-up and ablation failed in 5 limbs. One of the 11 limbs (9%) had a skin burn that required treatment.

CONCLUSION

Despite partly successful occlusion, we suggest that direct laser ablation cannot replace classic methods of treating branch varicosities, because of its high failure rate and the risk of skin burns.

Endovenous Laser Treatment for Varicose Veins in Patients with Active Ulcers: Measurement of Intravenous and Perivenous Temperatures during the Procedure

BACKGROUND

Conventional saphenous vein stripping is difficult to be indicated for the treatment of varicose veins in patients classified as CEAP C4, C5, or C6.

OBJECTIVE

This study was developed to evaluate treatment results for varicose veins with active ulcers using endovenous laser (EVL), compared to a group undergoing clinical treatment, during 1 year.

PATIENTS AND METHOD

Fifty-two patients presenting with varicose veins with active ulcers for more than 1 year were divided for treatment into two randomized groups: Group 1, clinical treatment, composed of 25 subjects, was submitted to elastic or inelastic compression therapy; Group 2, EVL treatment, composed of 27 subjects, was submitted to great and or small saphenous vein ablation with a 980-nm diode EVL, plus the clinical treatment. Intravenous and perivenous temperatures were measured continuously during the EVL treatment. All patients were followed for 12 months and studied with ultrasound at the beginning and end of the study. The ulcers' areas were evaluated initially and at every 3 months.

RESULTS

In 12 months, 81.5% of the wounds in patients in Group 2 and only 24% in patients in Group 1 had healed. Ulcer recurrence rate was 44.4% in Group 1. The mean wound area in Group 1 decreased from 17.48 to 12.76 cm(2) at the end of the year. In Group 2, the wound area decreased from 22.26 to 2.7 cm(2) (p=.0037). Mean intravenous and perivenous temperatures of 79.3 and 43.0 degrees C were recorded.

CONCLUSION

The treatment for varicose veins with EVL is safe in patients with active ulcers. Wounds healed faster than in patients undergoing clinical treatment alone during a 1-year period. There was no ulcer recurrence in patients treated with EVL.

Review of Intravascular Approaches to the Treatment of Varicose Veins

This is an in-depth review article for intravascular approaches to the treatment of varicose veins. The review discusses thermocoagulation of abnormal veins performed by an endoluminal radiofrequency device or laser. The article sites specific findings and is based on our clinical experience and extensive literature search. It was found that the two techniques were less invasive, less expensive, and faster alternative to treat varicose saphenous trunks compared to ligation and stripping. Minor adjustments to the technique prevented or minimized side effects to patients. Ambulatory phlebectomy in conjunction with treatment produced optimal long-term results.

[Primary varicosis]

The classic varicose vein operation still represents the "gold standard" in the operative therapy of varicose veins. The results of this procedure in view of perioperative complications are very good, with the incidence of perioperative deep venous thrombosis varying between 0.05% and 0.1%. Recurrence rates between 6% and 60% are published. However, the true recurrence rate is unknown since an exact definition of recurrent varicosis is still lacking. In recurrent varices it is essential to distinguish between disease progression, including neorevascularisation, and technical errors. Endovascular procedures for elimination of the superficial venous system - radiofrequency obliteration and endovenous laser therapy - meanwhile have established themselves as alternative, minimally invasive procedures. The perioperative complication rate of endovenous procedures is very low and comparable to that of the classic operation. Good results, with occlusion rates of the treated vein around 87% to 93% up to 2 years postoperatively, have been published for both endovenous laser therapy and radiofrequency obliteration. For the latter, 5-year results were published, with occlusion of the treated vein in 87%. Results in the literature for radiofrequency are better documented than for endovenous laser treatment because there are now five prospective randomised trials for the former and most publications for endovenous laser treatment are single-center experiences. The advantage of endovenous procedures, especially radiofrequency obliteration, over the classic operation is the lower rate of perioperative pain and better quality of life. The spectrum of operative treatment methods of the superficial venous system has increased tremendously due to new technical developments. For the surgeon this implies the necessity of informing patients conscientiously about the pros and cons and available results of each procedure, and carefully weighing which methods are at the time best for the patient.

Catheter-assisted vein sclerotherapy: a new approach for sclerotherapy of the greater saphenous vein with a double-lumen balloon catheter

OBJECTIVE

We sought to optimize sclerotherapy of the greater saphenous vein (GSV) by targeted application of foamed sclerosant by using a catheter.

METHODS

We designed a new double-lumen catheter that is inserted into the GSV. Via one lumen, a balloon at the tip of the catheter can be inflated to stop the blood flow. Via the second lumen, the sclerosing agent can be injected and aspirated. This method enabled us to perform a targeted application of the sclerosing agent [catheter-assisted vein sclerotherapy (KAVS)]. In an open study, outpatients suffering from varicosis of the GSV received a foam sclerotherapy under ultrasound guidance, using the newly developed KAVS catheter.

RESULTS

Thirty patients with an insufficiency (reflux) of the GSV were treated with the newly developed KAVS method using foamed polidocanol. The intervention was well tolerated in all patients without the occurrence of serious side effects. In 27 of the 30 treated patients (90%), we found a closure of the GSV at control visits 6 weeks, 3 months, and 6 months after treatment.

CONCLUSIONS

The KAVS method represents a feasible approach for sclerotherapy of the GSV. The efficiency and treatment modalities need to be explored in further studies.

Advances in the treatment of varicose veins: ambulatory phlebectomy, foam sclerotherapy, endovascular laser, and radiofrequency closure

Dermatologists have played a key role in the advancement and development of new safe, noninvasive technologies that are utilized in the treatment of both cosmetic telangiectasias and larger varicose veins of medical significance. As presented in this article, major advances in sclerosing solutions, hook avulsion techniques, and endovascular RF and laser procedures have revolutionized the world of phlebology. This medical sector continues to evolve through its relevance to the ever-expanding aesthetic and aging population.

Laser therapy of vascular lesions

Since the first construction of a laser by Maiman in 1960 and the first clinical application of a laser in the therapy of skin lesions by Leon Goldman, laser therapy has become an important therapeutic modality in dermatology. Various lasers can be used for the treatment of different vascular and non-vascular lesions. According to our results, vascular lesions constitute the most important indication for laser therapy in dermatology.

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.

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

Superficial vein surgery and SEPS for chronic venous insufficiency

Venous insufficiency in its severe forms leads to skin changes which, in turn may be treated by surgical therapy. Interventions are directed towards correction of the underlying abnormal venous physiology. This involves removal of varicose veins and ablation of incompetent axial veins and relevant perforating veins. In performing ablation of saphenous vein reflux, techniques include high ligation with stripping, radiofrequency ablation, endovenous laser therapy, and foam sclerotherapy. Incompetent perforator interruption can be accomplished surgically by subfascial endoscopic perforator surgery (SEPS) or controlled sclerotherapy using ultrasound. A variety of techniques have emerged to manage the varicose veins themselves. Surgical treatment of chronic venous insufficiency with high ligation in the groin and inversion stripping of the great saphenous vein to the knee combined with stab avulsion of varicose veins continues to be the standard in treatment of varicose veins. There are few comparisons of sclerotherapy of perforating veins with SEPS, but SEPS has become the most popular of surgical options.

Advances in the Treatment of Varicose Veins: Ambulatory Phlebectomy, Foam Sclerotherapy, Endovascular Laser, and Radiofrequency Closure

Several recent advances in the treatment of varicose veins have improved the safety, efficacy, comfort, efficiency, and long-term success of therapy. The advances of ambulatory phlebectomy, foam sclerotherapy, endovascular laser, and radiofrequency ablation with closure have made a significant positive impact on patient satisfaction. Duration of treatment and recovery is shorter, discomfort is minimized, and results are generally excellent. Studies assessing long-term outcomes are ongoing, and treatment modalities are continuing to evolve.