By 2001, clinical trials confirmed the success of a technique known as thermo-coagulation which utilised a focused radio frequency heat energy to break down the vessel wall through the skin causing its immediate disappearance. It was safe, reliable and relatively painless – a walk-in, walk-out procedure with no pre-care or aftercare required. Its application was limited however to the very fine superficial veins of up to 0.3mm thereby necessitating the complementary use of alternative treatments such as sclerotherapy to eradicate the larger reticular vessels.