The morphological basis for the Polster theory of penile vascular regulation.

The discovery of the papaverine erection test by Virag in 1982 stimulated the interest of research workers in the physiology of the penis. Since then, the scheme of functioning proposed by Conti [Acta anat. 14:217-262, 1952] in 1952 has been frequently cited in the literature, although its finalism is evident. It is based upon the presence of regulatory mechanisms along penile arteries, veins and arteriovenous anastomoses. In spite of the fact that these anastomoses were unanimously admitted, recently the presence of arterial and venous cushions has been controverted or even denied. Before attempting any functional explanation using nerves and chemical mediators, we made sure first of the concrete material reality of these anatomical structures. Thirty-five years after the main study, the present observations confirm the morphologic descriptions made in 1952. The contrary would have been astonishing. In fact, arterial and venous cushions were demonstrated by the School of Anatomy of Padova, the most ancient and venerable of all (Fallope, 1550), then by other institutes of morphology that dealt with these cushions in practically all the organs of the human body. It remains to establish their role in erection - whether it is null, complementary or primordial: that is the question.