Definitive treatment for spider veins involves injections. Some will claim that superficial lasers or radiofrequency generators can do the job…but, in my opinion…based on experience…I would recommend starting with sclerotherapy first and use those other modalities as a last resort or to treat veins too small to enter with a needle. Sclerotherapy Centuries old, the concept of injecting solution into varicose veins in order to get them to scar down and shrink is still a mainstay in the armamentarium of phlebologists. Like thermal ablation, the goal is to achieve irreversible damage to the cells that line the walls of veins, causing local inflammation and ultimately scarring down and resorption of the vein itself. Too little, the body can ultimately heal the damage and allow blood to continue to flow through diseased veins. Too much can allow the sclerosing agent to flow into normal healthy veins and cause unwanted damage.