Sclerotherapy is considered the gold standard treatment for removing spider and some varicose leg veins. It is a very cost-effective procedure that seldom leaves a scar or produces adverse effects.  A concentrated saline or specially developed chemical solution is injected with a very small needle into the spider or varicose vein. The solution causes the vein to close up or collapse and become scar tissue that is eventually absorbed by the body. The work of carrying the blood is shifted to other healthy blood vessels nearby.
Sclerotherapy generally requires multiple treatment sessions. One to three injections are usually required to effectively treat any vein. The same area should not be retreated for four to six weeks to allow for complete healing, although other areas may undergo treatment during this time. Walking and moderate exercise helps to speed recovery. Although sclerotherapy works for existing spider and varicose veins, it does not prevent new ones from developing, but may decrease this risk.

There is no down time and most patient report  minor, if any, side effects, which usually disappear in time. Temporary reactions can include a slight swelling of the leg or foot, minor bruising, pigmentation, the temporary appearance of new blood vessels, redness and mild soreness.