Brühlmann W, Zollikofer C, Hauri D
Rofo. 1987 Aug;147(2):165-8. doi: 10.1055/s-2008-1048614.
Based on the findings upon arteriography, cavernosography and clinical features two different kinds of priapism are differentiated: Type I ("low flow priapism") is characterized by severe blood stasis within the corpora cavernosa and reduction of arterial perfusion through compression of the deep arteries of the penis. The penis is very hard and painful upon palpation. A delay of treatment over 48 hours will result in a damage of the corpora cavernosa and impotence. Type II ("high flow priapism") is characterized by arterial hyperperfusion. Outflow obstruction is absent. The penis is erected but of an elastic consistence, pain is absent. Even with a delay of treatment of up to 6 months the corpora cavernosa remain intact, normal erectile function is preserved.