Sclerotherapy, an alternative to surgery for varicose veins, entails injecting a solution to irritate and collapse vein walls, so the
vein eventually disappears. A series of sessions is usually required
for a large area.
There are plenty of minimally invasive treatments to tackle varicose veins, including a new injectable solution that the Food and Drug Administration approved in March. Come June, the drug — called Asclera, widely used in Europe — will be available in the United States, giving American doctors another option for injecting the unsightly veins with fluid that makes them collapse.
This article in the May 13, 2010 NY Times is a good review of the "state of the art." See: New Help to Free Legs From a Web.