priapismo

Priapism is a prolonged, usually painful penile erection not related to sexual stimulation. An erection lasting more than four hours can cause ischemia of the erectile tissue and permanent damage if not treated promptly. Priapism is a urological emergency when ischemic and requires urgent assessment and management to restore normal blood flow and prevent erectile dysfunction.

There are different forms of priapism. Ischemic (low-flow) priapism is the most common and is typically painful, with a rigid penis and reduced venous outflow. Non-ischemic (high-flow) priapism results from unregulated arterial inflow, is usually less painful, and often follows trauma. A third form, stuttering priapism, involves recurrent episodes of erection that may require longer-term management.

Common causes include hematologic conditions such as sickle cell disease, other blood disorders, and malignancy; penile or perineal trauma; spinal cord injury or neurologic disorders; and use of medications such as trazodone, antipsychotics, or, less commonly, erectile dysfunction medications, especially in combination with other risk factors. Substances such as alcohol or recreational drugs can contribute. In many cases the exact cause remains unknown.

Diagnosis relies on history and physical examination, with blood gas analysis from cavernosal blood helping differentiate ischemic from non-ischemic priapism (ischemic blood is deoxygenated and acidic; non-ischemic blood has normal values). Penile Doppler ultrasound can assess blood flow when needed.

Treatment depends on the type. Ischemic priapism requires urgent decompression: aspiration of blood from the corpora cavernosa with irrigation, often followed by intracavernosal or systemic sympathomimetic medications (for example, phenylephrine). If these measures fail, surgical shunts or considerations of penile reconstruction may be necessary. Non-ischemic priapism is often observed, since it may resolve spontaneously; intervention is considered if it persists. Stuttering priapism requires management of underlying causes and may involve preventive strategies.