Sclerotherapy is the injection of a chemical irritant (sclerosing agent) into a vein to produce inflammation, a proliferation of connective tissue (i.e., fibrosis), and eventual obliteration of the lumen of the vein. The procedure is performed to treat varicose veins and sometimes telangiectasias. Varicose veins are dilated, thickened, elongated, and twisted vessels with incompetent venous valves, which are inefficient at preventing backflow of blood (Figure 1). Telangiectasias are permanent dilated and discolored small blood vessels often called spider veins (Figure 2).

Figure 1

Figure 2

Figure 1. The varicose veins on this person are a result of deep venous thrombosis 12 years earlier. Sclerotherapy and compression are valuable adjuncts in managing these problems. (From Gloviczki P, Yao, JST, eds. Handbook of Venous Disorders, 2nd ed. London: Arnold, 2001:255, Fig. 26.2).

Figure 2. Telangiectasias or spider veins on this 19-year-old. Telangiectasias have a familial tendency. (Gloviczki P, Yao, JST, eds. Handbook of Venous Disorders, 2nd ed. London: Arnold, 2001:255, Fig. 26.1).