Endovenous techniques for elimination of saphenous reflux: a valuable treatment modality

Endovenous laser with miniphlebectomy for treatment of varicose veins and effect of different levels of laser energy on recanalization. A single center experience

Varicose veins, associated with great saphenous vein (GSV) incompetence, are traditionally treated with conventional surgery. In recent years, minimally invasive alternatives to surgical treatment such as the endovenous laser ablation (EVLA) and radiofrequency (RF) ablation have been developed with promising results. Residual varicose veins following EVLA, regress untouched, or phlebectomy or foam sclerotherapy can be concomitantly performed. The aim of the present study was to investigate the safety and efficacy of EVLA with different levels of laser energy in patients with varicose veins secondary to saphenous vein reflux. From February 2006 to August 2011, 740 EVLA, usually with concomitant miniphlebectomies, were performed in 552 patients. A total of 665 GSV, 53 small saphenous veins (SSV), and 22 both GSV and SSV were treated with EVLA under duplex USG. At 84 patients, bilateral intervention is made. In addition, miniphlebectomy was performed in 540 patients. A duplex ultrasound (US) is performed to patients preoccupying chronic venous insufficiency (with visible varicose veins, ankle edema, skin changes, or ulcer). Saphenous vein incompetence was diagnosed with saphenofemoral, saphenopopliteal, or truncal vein reflux in response to manual compression and release with patient standing. The procedures were performed under local anesthesia with light sedation or spinal anesthesia. Endovenous 980-nm diode laser source was used at a continuous mode. The mean energy applied per length of GSV during the treatment was 77.5 ± 17.0 J (range 60-100 J/cm). An US evaluation was performed at first week of the procedure. Follow-up evaluation and duplex US scanning were performed at 1 and 6 months, and at 1 and 2 years to assess treatment efficacy and adverse reactions. Average follow-up period was 32 ± 4 months (3-55 months). There were one patient with infection and two patients with thrombus extension into the femoral vein after EVLA. Overall occlusion rate was 95%. No post-procedural deep venous thrombosis or pulmonary embolism occurred. Laser energy, less than 80 J/cm, was significantly associated with increased recanalization of saphenous vein, among the other energy levels. EVLA seems a good alternative to surgery by the application of energy of not less than 80 J/cm. It is both safe and effective. It is a well-tolerated procedure with rare and relatively minor complications.

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.

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