Diagnostic tests for impotence: a comparison of papaverine injection with the penile-brachial index and nocturnal penile tumescence monitoring.

The diagnostic usefulness of nocturnal penile tumescence monitoring, penile-brachial index and intracorporeal injection of papaverine (60 mg. in 20 ml. normal saline) was compared in 43 impotent men. Intracorporeal pressure was measured with a pressure transducer. Based on turgidity, and the time of onset and duration of erection, we classified the impotence as psychogenic/neurogenic (normal vascular competence), mild or severe arteriogenic, or venogenic. The intracorporeal injection of papaverine was useful as a functional diagnostic test for impotence. The penile-brachial index, an indirect measurement of the flaccid penis, did not correlate well with the results of the papaverine test. A poor response to papaverine injection documents organic impotence and, under these circumstances, nocturnal penile tumescence monitoring is not necessary. We conclude that the intracorporeal injection of papaverine currently is the best screening technique for the differential diagnosis of vasculogenic impotence.