Priapism is defined as an erection lasting more than 4 hours that is not associated with sexual stimulation. It is generally classified into two types: ischemic (no blood flow) and non-ischemic (constant blood flow). The former, comprising the vast majority of cases, is considered an emergency due to the associated pain as well as to structural changes in the penis that may lead to penile fibrosis and severe erectile dysfunction. Conservative management is rarely effective except in select circumstances. Interventions may include aspiration of the blood in the penis, injection of vasoconstrictive agents, or surgical procedures. Non-ischemic priapism presents less emergent risks, and may be followed conservatively. If intervention is necessary, angiographic embolization is often the best therapeutic option.
We have written extensively on this problem [links to AUA update, Emergencies chapter, T-shunt article, pocketmedicine, ] and helped create one of the commonly used procedure to relieve priapism. [link to T-shunt article]
Ischemic priapism is often from unknown causes but may be the result of medications, neurologic disease, or blood abnormalities such as sickle cell anemia.
Non-ischemic priapism is usually caused by injury to the perineum, such as a “straddle injury”.
Ischemic priapism is an emergency, since if it neglected it can cause permanent damage to erections. Treatment usually starts with getting out the old blood with a needle and injecting a drug that reverses the erection. If this is not successful, various procedures are usually tried until the erection and pain are gone. If the priapism DOES cause erection problems, the patient usually requires a penile prosthesis. This is a very difficult surgery after priapism (because of scarring) and the patient should be very careful about choosing their surgeon for the best outcome.
Non-ischemic priapism is not an emergency, since it does no harm to the erections. Most of the time, the erection will go away although it may take a long time (weeks or even months); if the erection does not go away, techniques are available to block the injured blood vessels to restore normal erections.