From a clinical point of view, priapism is defined as a prolonged and painful erection, unrelated to sexual desire.
There exists an unbalanced equilibrium between arterial inflow and penile venous drainage. The state of erection is limited to the cavernous bodies, without affecting the spongy body or the glans as it happens in the physiological erection.
Since the introduction of intracavernous injections of vasoactive drugs into medical practice, the incidence of priapism has increased enormously, becoming a relatively frequent entity. It has been described in all groups and ages.
Venous-occlusive priapism is an emergency, so it is important to know its pathophysiology, diagnosis and treatment of this entity that if not properly identified can determine the appearance of a definite impotence for the patient.
For a normal erectile response there must be a hemodynamic balance between the arterial supply and the venous drainage of the cavernous bodies. The breaking of this balance causes priapism.
Basically, two responsible physiopathological mechanisms have been described. As we will see, each of them offers a different etiological mechanism, prognosis and treatment.
Will Priapism Go Away On It’s Own?
Priapism is a medical emergency and, therefore, the patient must be treated immediately. However, priapism can resolve spontaneously, which occurs more often in the child, so sometimes it does not need treatment. It is advisable to establish a reasonable waiting period (3 to 4 hours), after which it will be necessary to start treatment.
High Flow, Pulsatile or Non-Ischemic Priapism
The maintenance of the erection is not due to an active muscle relaxation of the cavernous bodies, but to a permanently increased arterial flow, being the venous drainage normal, but insufficient to cause detumescence (process of decreased erection after orgasm and ejaculation). The absence of blood stasis, which means slowing or pooling of blood, explains its good tolerance. It is usually caused by arterial or penile trauma with laceration of the cavernous artery or one of its branches.
In this type of priapism, the cavernous lesions are less serious and require much more time to be established than those with low flow. Therefore, the evolution is favorable for the subsequent maintenance of sexual function.
Low Flow, Stasis or Ischemic Priapism
This form of priapism is the most frequent and the one with the greatest potential to cause a permanent alteration in the erectile function of the penis. In veno-occlusive priapism there is a partial or complete obstruction of the drainage of the cavernous bodies. Once these have reached their maximum expansion, the obstruction prevents the inflow of arterial blood and, therefore, an ischemic state is established inside the cavernous bodies.
- Clinical Presentation
- Veno Occlusive Priapism
The patient goes agitated to the emergency room, with a painful erection lasting several hours. Except in cases associated with intracavernous injection, the patient usually notices for the first time the prolonged erection on waking, in the middle of the night, or after having sexual intercourse. This temporal relationship with nocturnal or sexual erections suggests that in many cases the primary alteration that leads to priapism is the interference with the physiological mechanisms that regulate the detumescence of the erection. The penis usually presents a complete erection and is painful to the touch.
The patient always refers to a history of trauma that, when it is a perineal contusion or penis, may have occurred from a few hours to a few days before the appearance of priapism. When it comes to a penetrating trauma, usually by needle, priapism is usually established immediately. Although some patients manifest certain discomfort associated with erection, this form of priapism is usually painless and, of course, does not present the severe ischemic pain that characterizes veno-occlusive priapism. The penis is usually found in an incomplete state of erection (60-75%), is not painful to the touch, and has an elastic consistency to inspection.
Regardless of the etiology, the prognosis depends on the time of evolution and this is also the result of the different therapeutic actions.