Priapism

Most cases of priapism involve failure of detumescence and are most commonly due to failure of venous outflow (ie, low flow), also known as ischemic priapism. Severe pain from ischemia occurs after 4 hours. If prolonged > 4 hours, priapism can lead to corporeal fibrosis and subsequent erectile dysfunction Erectile Dysfunction Erectile dysfunction is the inability to attain or sustain an erection satisfactory for sexual intercourse. Most erectile dysfunction is related to vascular, neurologic, psychologic, and hormonal... read more or even penile necrosis and gangrene.

Stuttering priapism is a recurrent form of ischemic priapism with repeated episodes and intervening periods of detumescence.

Less commonly, priapism is due to unregulated arterial inflow (ie, high flow), usually as a result of formation of an arterial fistula after trauma. Nonischemic priapism is not painful and does not lead to necrosis. Subsequent erectile dysfunction is common.

History of present illness should cover the duration of erection, presence of partial or complete rigidity, presence or absence of pain, and any recent or past genital trauma. The drug history should be reviewed for offending drugs, and patients should be directly asked about the use of recreational drugs and medications used to treat erectile dysfunction.

Review of systems should seek symptoms suggesting a cause, including dysuria Dysuria Dysuria is painful or uncomfortable urination, typically a sharp, burning sensation. Some disorders cause a painful ache over the bladder or perineum. Dysuria is an extremely common symptom... read more (urinary tract infections Introduction to Urinary Tract Infections (UTIs) Urinary tract infections (UTIs) can be divided into upper tract infections, which involve the kidneys ( pyelonephritis), and lower tract infections, which involve the bladder ( cystitis), urethra... read more ), urinary hesitancy or frequency (prostate cancer Prostate Cancer Prostate cancer is usually adenocarcinoma. Symptoms are typically absent until tumor growth causes hematuria and/or obstruction with pain. Diagnosis is suggested by digital rectal examination... read more ), fever and night sweats (leukemia Overview of Leukemia Leukemia is a malignant condition involving the excess production of immature or abnormal leukocytes, which eventually suppresses the production of normal blood cells and results in symptoms... read more ), and lower-extremity weakness (spinal cord pathology).

Past medical history should identify known conditions associated with priapism (see table Some Causes of Priapism Some Causes of Priapism ), particularly hematologic disorders. Patients should be asked about a family history of hemoglobinopathies (sickle cell disease Sickle Cell Disease Sickle cell disease (a hemoglobinopathy) causes a chronic hemolytic anemia occurring almost exclusively in people with African ancestry. It is caused by homozygous inheritance of genes for hemoglobin... read more or thalassemia Thalassemias Thalassemias are a group of inherited microcytic, hemolytic anemias characterized by defective hemoglobin synthesis. Alpha-thalassemia is particularly common among people with African, Mediterranean... read more ).

A focused genital examination should be done to evaluate extent of rigidity and tenderness and determine whether the glans and corpus spongiosum are also affected. Penile or perineal trauma and signs of infection, inflammation, or gangrenous change should be noted.

The general examination should note any psychomotor agitation, and the head and neck examination should look for pupillary dilation associated with stimulant use. The abdomen and suprapubic area should be palpated to detect any masses or splenomegaly, and a digital rectal examination should be done to detect prostatic enlargement or other pathology. Neurologic examination is useful to detect any signs of lower-extremity weakness or saddle paresthesias that might indicate spinal pathology.

The following findings are of particular concern:

In most cases, the clinical history reveals a history of drug treatment for erectile dysfunction Erectile Dysfunction Erectile dysfunction is the inability to attain or sustain an erection satisfactory for sexual intercourse. Most erectile dysfunction is related to vascular, neurologic, psychologic, and hormonal... read more , illicit drug use, or a history of sickle cell disease Sickle Cell Disease Sickle cell disease (a hemoglobinopathy) causes a chronic hemolytic anemia occurring almost exclusively in people with African ancestry. It is caused by homozygous inheritance of genes for hemoglobin... read more or trait; in these cases, no testing is indicated.

In patients with ischemic priapism, physical examination typically reveals complete rigidity with pain and tenderness of the corpus cavernosa and sparing of the glans and corpus spongiosum. By contrast, nonischemic priapism is painless and nontender, and the penis may be partially or completely rigid.

If the cause is not obvious, screening is done for hemoglobinopathies, leukemia Overview of Leukemia Leukemia is a malignant condition involving the excess production of immature or abnormal leukocytes, which eventually suppresses the production of normal blood cells and results in symptoms... read more , lymphoma Overview of Lymphoma Lymphomas are a heterogeneous group of tumors arising in the reticuloendothelial and lymphatic systems. The major types are Hodgkin lymphoma Non-Hodgkin lymphoma See table Comparison of Hodgkin... read more , urinary tract infection Introduction to Urinary Tract Infections (UTIs) Urinary tract infections (UTIs) can be divided into upper tract infections, which involve the kidneys ( pyelonephritis), and lower tract infections, which involve the bladder ( cystitis), urethra... read more , and other causes:

Many clinicians also do drug screening, intracavernosal arterial blood gas testing, and duplex ultrasonography Variations of Ultrasonography In ultrasonography, a signal generator is combined with a transducer. Piezoelectric crystals in the signal generator convert electricity into high-frequency sound waves, which are sent into... read more . Penile duplex ultrasonography will show little or absent cavernosal blood flow in men with ischemic priapism and normal to high cavernosal blood flow in men with nonischemic priapism. Ultrasonography may also reveal anatomic abnormalities, such as cavernous arterial fistula or pseudoaneurysm, which usually indicate nonischemic priapism. Occasionally, MRI with contrast is useful to demonstrate arteriovenous fistulas Arteriovenous Fistula An arteriovenous fistula is an abnormal communication between an artery and a vein. An arteriovenous fistula may be congenital (usually affecting smaller vessels) or acquired as a result of... read more or aneurysms Overview of Aortic Aneurysms Aneurysms are abnormal dilations of arteries caused by weakening of the arterial wall. Common causes include hypertension, atherosclerosis, infection, trauma, systemic rheumatic diseases, and... read more .

Treatment should begin immediately, typically with aspiration of blood from the base of one of the corpora cavernosa using a nonheparinized syringe, often with saline irrigation and intracavernous injection of the alpha-receptor agonist phenylephrine. For phenylephrine injections, 1 mL of 1% phenylephrine (10 mg/mL) is added to 19 mL of 0.9% saline to make 500 mcg/mL; 100 to 500 mcg (0.2 to 1 mL) is injected every 5 to 10 minutes until relief occurs or a total dose of 1000 mcg is given. Before aspiration or injection, anesthesia is provided with a dorsal penile nerve block or local infiltration.

If these measures are unsuccessful or if priapism has lasted > 48 hours (and is thus unlikely to resolve with these measures), a surgical shunt can be created between the corpus cavernosum and glans penis or corpus spongiosum and another vein.

Stuttering priapism, when acute, is treated in the same way as other forms of ischemic priapism. There is a report of several cases caused by sickle cell disease Sickle Cell Disease Sickle cell disease (a hemoglobinopathy) causes a chronic hemolytic anemia occurring almost exclusively in people with African ancestry. It is caused by homozygous inheritance of genes for hemoglobin... read more that responded to a single oral dose of sildenafil. Treatments that may help prevent recurrences of stuttering priapism include antiandrogen therapy with gonadotropin-releasing hormone agonists, estrogen, bicalutamide, flutamide, phosphodiesterase type-5 inhibitors, and ketoconazole. The goal of antiandrogen therapy is to decrease the plasma testosterone level to < 10% of normal. Digoxin, terbutaline, gabapentin, and hydroxyurea have also been tried with some success.

Conservative therapy (eg, ice packs and analgesics) is usually successful; if not, selective embolization or surgery is indicated.

If other treatments are ineffective, a penile prosthesis can be placed.