Objective: Compare venous occlusion rates at a one-year follow-up comparing 1920-nm versus 1470-nm laser treatment. Design: Non-randomized prospective study. Methods: Adult patients with varicose veins associated with great saphenous reflux were included. Procedures were performed between February and April of 2013. The 1470-nm laser ablation was performed in continuous mode, power being set between 8 and 10 W, while for the 1920-nm it was set between 5 and 6 W. Checking for vein closure was performed during the thermal ablation procedure, LEED (linear endovenous energy density) being calculated after the procedure. Follow-up data were collected at the 7-day, 30-day, 3-month, 6-month and 1-year visits, and involved clinical and ultrasound evaluation, measurement of occlusion extent.

INTRODUCTION The treatment of varicose veins secondary to saphenous vein reflux has undergone a major shift in the past decade, primarily led by the introduction of less invasive techniques. Wavelengths of 810, 940 and 980 nm have higher rates of absorption by hemoglobin. Water chromophore is associated with an initial energy absorption peak at 980 nm, followed by peaks at 1500 and 2000 nm. The energy released into the vein lumen is therefore absorbed by water as well as by cellular and interstitial proteins. In contrast, laser beams with longer wavelengths act more specifically on water absorbance, resulting in less energy expenditure, such as in the case of the 1470-nm diode endolaser. An endoluminal energy density (LEED) around 50-160 J/cm has been demonstrated to effectively lead to venous occlusion, although LEEDs above 100 J/cm can also be associated with higher complication rates. In contrast, the 1920-nm diode laser is more specific for water and hemoglobin chromophores, tissue absorption at this wavelength being at least 2.5 times greater than the one obtained with the 1470-nm laser. It is therefore expected that less energy would be required to generate the same amount of venous closure.

The aim of this study is to compare diode 1920-nm versus 1470-nm laser in the treatment of great saphenous vein reflux. The primary outcome was venous segment occlusion at the one-year follow-up. Secondary outcomes included LEED, postoperative complications, and clinical outcomes measured through the Clinical, Etiology, Anatomical and Pathological classification (CEAP), the Venous Clinical Severity Score (VCSS) and a patient satisfaction scale.

METHODS This is a prospective study to evaluate the results of the 1920-nm vs. 1470-nm laser. Patients agreeing to participate were offered informed consent, recruitment occurring between February and April of 2013. Participants enrolled between February and mid-March of 2013 underwent treatment with the 1470-nm laser, while those enrolled between mid-March and April underwent treatment with the 1920-nm laser.

Patients between 18 and 70 years old who had varicose veins associated with reflux of the great saphenous veins were included. The exclusion criteria were: patients with a previous history of thrombophlebitis, deep vein thrombosis or who had undergone any previous surgery for this condition, thermal ablation or sclerotherapy. For bilateral cases, both limbs were treated during the same surgical session.

Data on clinical history, physical examination, CEAP classification, VCSS (Venous Clinical Severity Score) and VDS (Venous Disability Score) were collected. The extent of the great saphenous reflux was measured along with its main diameter at the level of the saphenofemoral junction as well as at the knee level. Reflux was defined as retrograde when reaching a speed greater than 3 cm/second during a Valsalva maneuver or through leg compression maneuvers.

All patients underwent procedures under spinal anesthesia. The great saphenous vein was punctured at the most distal point of reflux and a 6F introducer was positioned. All cases were conducted with a 600-micron radial fiber positioned between 2.0 and 3.0 cm from the saphenofemoral junction. A tumescence with 0.9% saline solution was placed under ultrasound guidance around the full length of the saphenous vein. All patients were in a 30-degree Trendelenburg position. Surgical procedures involved the saphenous ablation and phlebectomy.

Saphenous ablation with a 1470-nm laser was performed in continuous mode, with a power of 8 to 10 W, determined as a function of the diameter of the vessel as well as surgeon's preference. The 1920-nm laser was also used in continuous mode, with 5 to 6 W power. Vein closure monitoring during the thermal ablation procedure was conducted through ultrasound while pulling-off the fiber. At the end of the procedure, the total amount of energy used in each limb was recorded for LEED calculation, measured as total energy used in the limb (J) over vein length (cm).

First follow-up occurred at postoperative week one, with subsequent evaluation at 30 days, three months, six months and one year. At each assessment, symptoms were recorded and an ultrasound evaluation was performed. Patient satisfaction was evaluated at 1-week through the following questions "Are you satisfied with your surgery?" and "Would you choose the same treatment again?" Both questions were presented as a Likert scale where 0 = very satisfied, 1 = satisfied, 2 = indifferent, 3 = not satisfied, 4 = very dissatisfied.

The primary endpoint for this study was the percentage of occluded venous segments at the 6-month follow-up. Extension of the occluded saphenous vein segment was measured at each visit through a tape guided by ultrasound to determine occlusion points. A segment was considered patent if it was compressible and with reflux after muscle compression in a standing position. The length of the occluded vein segment was compared with the length of the segment where thermal ablation was performed, thus allowing us to calculate the segment closure percentage. Secondary end-points were the presence of ecchymosis, induration, paresthesia, skin burns and deep vein thrombosis.

Inclusion Criteria:

• Patients with varicose veins associated with reflux of great or small saphenous veins

Exclusion Criteria:

• Patients under 18 years old or over 70 years.
• Acute or previous thrombophlebitis or deep vein thrombosis.
• Pregnant patient.