Changes in penile skin blood flow following intracavernosal injection of papaverine.

Marked changes in penile skin blood flow following intracavernosal injection of papaverine were observed in 14 subjects. Increased flow was more pronounced in those patients who failed to achieve erection or had poor erection than in those who responded with adequate erection. This observation may explain in part why papaverine fails in subjects responding to prostaglandin E1. It raises the suspicion of a corporal cutaneous shunt, which may influence the choice between the use of an external vacuum device and venous surgery in certain cases of venogenic impotence.