Priapism is a rare but serious condition characterized by a persistent erection of the penis that occurs independently of sexual arousal. Priapism is characterized by a painful erection that lasts longer than two hours and often requires medical treatment. It is usually caused by impaired blood outflow from the corpora cavernosa.
Ischemic priapism—also known as low-flow priapism—in particular constitutes a urological emergency. Without immediate treatment, permanent erectile dysfunction may result. In addition to blood disorders such as sickle cell anemia or leukemia, psychotropic medications, SKAT injections, or injuries can also trigger priapism. Treatment for priapism ranges from cooling and puncture to aspiration, surgical shunting, or arterial procedures such as embolization.
Types of Priapism
There are two distinct forms of this condition: low-flow priapism and high-flow priapism.
Low-Flow Priapism
In this form of prolonged erection, the penis becomes very hard and the glans takes on a pale bluish color. Blood cannot flow out of the corpora cavernosa because they are blocked. As a result, blood remains in the tissue and puts pressure on the corpora cavernosa.
This can cause unpleasant pain and a decrease in the oxygen content of the blood. This may lead to changes in the tissue of the corpora cavernosa, which can result in a loss of erectile function. This form of prolonged erection accounts for approximately 90 percent of all cases.
An Etruscan statue of Priapus
High-Flow Priapism
High-flow priapism accounts for about 10 percent of all cases. This is usually caused by injuries to the perineal or genital area. In this condition, a large amount of blood flows uncontrollably through the arteries into the erectile tissue of the penis. As a result, unlike in low-flow priapism, the penis tends to be more elastic and pulsates.
The erection causes little or no pain. Since the blood can flow out unimpeded, the oxygen content in the blood remains unchanged, which is why the risk of losing sexual function is much lower with this form of prolonged erection.
Mixed Forms of Priapism
In addition to high-flow and low-flow priapism, mixed forms can also occur. These often result from the use of medications to treat erectile dysfunction.
Causes of a prolonged erection
A persistent erection can have many causes. Often, these remain unexplained. Factors that can trigger a persistent erection include:
- urological conditions (such as inflammation of the penis or penile cancer)
- Disorders of the hematopoietic system (e.g., leukemia)
- dialysis (blood purification)
- diabetes
- neurological disorders (e.g., inflammation or brain tumors)
- Vascular diseases (e.g., blood clotting disorders)
- Medications (e.g., psychotropic drugs or blood pressure medications)
- Drug and alcohol use
- Injuries to the perineum and penis
- Complications associated with the treatment of erectile dysfunction
Diagnosis
If the prolonged erection lasts longer than two hours, a doctor should be consulted immediately.
The doctor will first ask about the patient’s medical history. This includes, for example, whether the patient has had a prolonged erection before, suffers from certain medical conditions, or is taking any medications.
In addition, the doctor will examine the penis externally and may check the perineal and genital areas for injuries. Furthermore, the doctor may draw blood from the penile corpora cavernosa to perform a blood gas analysis. This helps distinguish between low-flow and high-flow priapism.
In the case of low-flow priapism, the blood is dark in color and has a low pH level. If the patient has high-flow priapism, the blood is bright red and has a nearly normal pH level.
In addition, the doctor may perform an ultrasound examination. This assesses the inflow and outflow of blood into the corpora cavernosa. In low-flow priapism, there is hardly any detectable outflow of blood.
Treatment of Low-Flow Priapism
Treatment for a persistent erection should begin no later than four to six hours after the onset of the erection to prevent long-term damage.
In cases of low-flow priapism, treatment ensures that blood can flow out of the corpora cavernosa again. To do this, the pooled blood is aspirated by puncturing the penis with a syringe. In addition, the corpora cavernosa are flushed with a saline solution. Furthermore, the doctor may also inject a substance into the penis that causes the muscles to contract, allowing the blood to drain away.
If these treatment methods do not produce the desired result, the patient will require surgery on the penis. During the surgery, a so-called shunt is placed between the blood-filled corpora cavernosa and the glans. The shunt acts as a bypass, allowing blood to flow out of the penis again.
Treatment of High-Flow Priapism
The persistent erection associated with high-flow priapism usually subsides on its own.
In the rare cases where this does not happen, the doctor may perform an angiogram. During this procedure, after administering a contrast agent, the doctor can visualize the patient’s blood vessels. The damaged vessel is then closed off using embolization (artificial vessel occlusion). However, this method itself can lead to erectile dysfunction.
Another option is medication that helps reduce the persistent erection.
FAQ
What is priapism?
Priapism is a painful, prolonged erection of the penis that occurs without sexual arousal. The erection lasts at least two hours or longer and usually affects the erectile tissue, specifically the corpus cavernosum. Priapism is a medical emergency and should be treated promptly by a doctor.
What types of priapism are there?
A distinction is made between ischemic priapism (low-flow type) and high-flow priapism. In ischemic priapism, venous blood flow is impaired, preventing blood from draining from the corpora cavernosa. Arterial, or non-ischemic, priapism, on the other hand, is often caused by damage to an artery.
What are the possible causes of priapism?
Causes of priapism include sickle cell anemia, leukemia, blood disorders, and certain medications or psychotropic drugs. Injections for the treatment of erectile dysfunction, SKAT therapy, or injuries can also trigger priapism. In some cases, the exact cause remains unclear.
How is priapism treated?
Treatment for priapism depends on the type and duration of the symptoms. In cases of ischemic priapism, aspiration or puncture with saline solution and medications such as epinephrine is often performed. If conservative therapy is ineffective, a shunt can be surgically implanted or embolization can be performed.
Why is priapism a medical emergency?
If a painful, prolonged erection lasts longer than two hours, the tissue of the corpora cavernosa can be damaged. Without immediate treatment, there is a risk of permanent erectile dysfunction. Therefore, priapism constitutes a urological emergency.
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Sabine Schneider
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