Penile polsters: functional structures or atherosclerotic changes?

The distribution of blood flow within the penis during erection and detumescence is thought to be controlled by polsters, columns of smooth muscle cells within the intima of penile arteries and veins. We have examined penile tissue from 4 men and 2 children, and have been unable to find incontrovertible evidence of polsters as classically described. Occasional structures superficially resembling polsters were encountered not only in penile tissue but also in vessels in the spermatic cord in patients undergoing vasectomy. In each instance these structures were recognizable as either branching points of vessels, intimal smooth muscle cell cushions or atherosclerotic lesions at various stages of development. Our findings strongly refute the hypothesis that polsters contribute to the normal physiology of erection.