Alteration in collagen and elastin content in varicose veins

The nature and distribution of venous disease surrounding the development of varicose veins is controversial. Collagen and elastin are important components of the vein walls that affect their function. Collagen provides tensile strength, and elastin provides tissue elasticity. The amount of collagen and elastin was studied biochemically and histologically in two groups of human normal and varicose veins. The collagen content was higher in both dilatated and morphologically normal segments of varicose veins when compared with normal veins, whereas the elastin content was markedly decreased only in the dilatated segments of varicose veins. The ratio of thick to thin collagen fibers was almost invariable. These findings were consistent with the morphologic fibrosis that has regularly been described in varicose veins and emphasize the important role of elastin in providing the retractive force that opposes the development of dilatation and tortuosity of the vein wall.