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).