Histopathology of great saphenous vein valves in primary venous insufficiency

Objective: To verify some of the previous findings of venous valves described in the literature, their pathophysiological significance, and the clinical implications. Materials and methods: The elementary components of 65 proximal valves of the great saphenous vein and their interrelationships were subjected to histopathological examination. Valves were taken from patients subjected to great saphenous vein surgical removal for varicose veins of the lower limbs. Measurements and morphological evaluations were performed by optical microscopy. Results: The valvular sinus, leaflet insertion segment, and proximal portion of the cusp undergo parallel variations of thickness. The thickening of the proximal portion of cusp is related to the smooth muscle cells increasing in the leaflet insertion segment, and the elastic layer dissociation. The thickening of the distal portion of cusp depends on the collagen component, and it may shorten, crumple, and lead to the formation of a thickened border. The vein wall in a commissural aneurysm is usually thinner than in the valvular sinus. Alterations in the intima, in the elastic membrane, and in the media were found in the 98% of the valvular anulus. Ectasia and asymmetry of the venous wall are mainly related to the muscular hypoplasia of the media. Conclusions: The development of primary venous insufficiency seems to be due to the following tissue alterations: dilatation of the valvular anulus and hypotrophy of the cusp. The hemodynamic mechanical injury increases the tissue damage of both anulus and cusps. This pathophysiological interpretation of venous insufficiency leads to the need a detailed diagnostic procedure before reparative surgery of valves.