The purpose of this study is to describe the elastic fibers of varicose collateral saphenous veins. Sections were obtained from venous segments of patients with essential varices and stained with resorcin-fuchsin for elastic system fibers and analyzed with laser scanning microscopy after Evans blue staining. Vein portions (270 microm) were classified as without thickening, with a cushion, or with a diffuse thickening. The elastic material density of the intima (Dei) and media (Dem) were tested for differences by the Kruskal-Wallis test. Diffuse thickening (87.1+/-8.6 microm) represents 54.5% of the segment. Cushion occupies 23.5% with 42.4+/-4.66 microm. The elastic network present in the cushion is formed by elastic fibers of different diameters that branch into delicate oxytalan fibers in association with the smooth muscle cells. The diffuse thickening elastic network varies from elastic lamellae and delicate oxytalan fibers related to the intima smooth muscle cell bundles to fragmented elastic fibers in the collagenous areas. Dei increases as the intima enlarges (10.19, 14.63, and 16.01, respectively to without thickening, cushion, diffuse thickening). In the media, the elastic network encircles the circular muscle bundles connecting them to the elastic internal lamina and to elastic fibers in the adventitia. Smooth muscle cells were coiled by numerous oxytalan fibers and the elastic fibers are irregular and fragmented. In the sclerotic portions, the elastic fibers are sparse. No correlation was found between Dei and Dem. The important thickening of varicose vein intima shows increasing quantities of elastic material formerly associated with smooth muscle cells. In the media, the elastic network around smooth muscle cell bundles is disrupted and the Dem diminishes as the media becomes sclerotic.