The rationale for pharmacologic cavernosography.

To refine the diagnostic method for opacification of aberrant venous drainage in venogenic impotence, an experimental study was done in eight monkeys. In all monkeys, cavernosography after induction of erection by saline perfusion showed significant drainage via the cavernous veins. However, when cavernosography was performed after neurostimulation or papaverine injection, no cavernous drainage was visualized, even when the intracavernous pressure had been significantly lowered by creation of an artificial cavernous leak. Because erection can result from saline perfusion only when the volume perfused exceeds the venous outflow capability, cavernosography during saline-induced erection will always demonstrate the entire venous system and, thus, is of no diagnostic value. Pharmacocavernosography imitates the physiologic venous occlusive mechanism and should therefore be used to identify the abnormally draining veins in venogenic erectile dysfunction.