A venous valve is bicuspid (having two leaflets) and it is formed by an infolding of Portion of the tunica intima on possibly aspect with the lumen of the veins. The leaflets are strengthened with collagen, and elastic fibres, and covered with endothelium.[10] The endothelial cells on the surfaces on http://sgvascularctr.com/understanding-venous-leak-treatment-in-singapore/