Since the first application of lasers in medicine and surgery, the safe use of light energy to painlessly eliminate spider veins of the leg has been the holy grail of laser technology. However, lasers typically do not achieve equivalent results; sclerotherapy remains the gold standard of treatment for leg veins. As the successful use of lasers and light sources for facial vessels is widely known, patients seeking cosmetic treatment for their legs often request laser as they believe it is more effective, less painful, and less invasive than sclerotherapy. Although sclerotherapy causes an inflammatory reaction sometimes accompanied by side effects such as postsclerosis pigmentation and/or telangiectatic matting, lasers cause tissue destruction by conversion of light energy to heat absorption by the target tissue.1 This heat denatures protein, primarily vein wall collagen, although other blood proteins and muscular layers can denature as well. Heating is a process that should theoretically lead to less of an inflammatory reaction than that seen with sclerosing solutions, but this is not always the case.
One of the responsibilities of the treating physician is to explain to the patient the differences between thermal and chemical destruction in terms of efficacy, risks, and side effects. Some recent advances have permitted lasers and intense pulsed light (IPL) devices to become methods for treating telangiectatic vessels of the leg with reduced risks of adverse effects and greater efficacy compared to previous devices. Consensus over a perfect device has not been reached. Consideration of the principles and physics involved will allow the physician to choose a laser or light source suitable to the size, location, and oxygenation state of a targeted vessel as well as the skin color of the patient.
Laser versus Sclerotherapy
A complicating factor for laser treatment of leg veins is that most telangiectases are associated with high reverse pressure from associated reticular veins. Most lasers or IPL (except possibly 1064-nm lasers) will not treat the associated high-pressure reticular veins. The success rate is therefore greatly diminished for any treatment of telangiectasias when proximal hydrostatic pressure remains. Additional problems with treating leg veins as opposed to facial veins are the deeper and varied locations of leg veins, their thicker and larger walls, the overall larger vessel diameter through which the laser must penetrate, and the reduced oxygenation state leading to a violaceous rather than red color. Red telangiectasia have been found to have an oxygen saturation of 76 percent compared with blue telangiectasia that have an oxygen concentration of 69 percent.2 Thus, each type of telangiectasia may have a slightly different optimal wavelength absorption based on its color in addition to its relative size and depth. With all of these hurdles, it is inherently more difficult to get photons safely and in sufficient number through melanin into the target chromophore in leg veins as compared to facial vessels. One must employ specific measures to decrease ...