Priapism is defined as an erection lasting more than four 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 first, which is the 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 scarring and severe erectile problems. Conservative management is rarely effective except in select circumstances. Interventions may include aspiration of the blood in the penis, injection of medicines to relieve the erections 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.
The causes of ischemic priapism are often unknown but may be the result of medications, neurologic disease or blood abnormalities such as sickle cell anemia. Ischemic priapism is an emergency, since, if left alone, it can cause permanent damage to erections. Treatment usually starts with getting out the old blood in the penis 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 results in permanent 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 a urologist with experience for the best outcome.
Non-ischemic priapism is usually caused by injury to the perineum, such as a “straddle injury”. It 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