A minimally invasive procedure that is sometimes needed as a follow-up to the Endovenous Laser Ablation. Sclerotherapy is used to treat the smaller varicose and spider veins that cannot be lasered due to the size of the vessel. During this procedure, a solution is injected directly into the vein, causing the vein to collapse and forcing the blood to re-route through healthy veins. Over time, the treated vein is re-absorbed by the surrounding tissue and eventually disappears. Treated veins will typically fade within a few weeks, but in some instances it can take a month or longer to achieve desired results. Several sclerotherapy treatments may be needed to treat larger varicose or reticular veins.