Study of human penile venous system and hypothesis on its behavior during erection

To determine the role of the venous outflow restriction during human erection, we compared intracavernous pressure with deep dorsal vein pressure in 6 normal subjects during papaverine-induced erection and penile saline infusion. In addition, flows necessary to produce and maintain erection were measured in 10 cadavers before and after resection of the deep dorsal vein alone or together with ligation of the cavernous veins. Elongation of tunica albuginea was measured at the crural and mid portions of the penis. At rigidity there was complete blockage of the venous return through the emissary veins. The venous outflow through the cavernous veins was reduced but still persisted. The distention of the tunica albuginea was less important at the crural portion than at the distal portion and could explain why the cavernous veins were not blocked completely.