What is Priapism?
Priapism is a medical condition involving the persistent erection of the penis or the clitoris, despite absence of stimulation that can last up to four hours. Because of the persistent erection for hours, it leads to severe pain because of poor blood circulation.
Priapism is considered a medical emergency because it may lead to severe ischemia of the tissues. Early emergency treatment often prevents functional disabilities such as erectile dysfunction and disfiguring of the penis.
Priapism usually results from the trapping of blood in the penis leading to prolonged erection. Priapism can affect both males and female and can also affect all age groups.
Persistent erection of the penis or priapism
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It involves different types such as:
Ischemic or low flow
This type results from the inability of the blood to leave the penis after going to the area during stimulation. Up to 90% of priapism cases are ischemic in type. Males with leukemia, malaria or sickle cell anemia may suffer from ischemic priapism.
Non-ischemic or high flow
Non-ischemic priapism occurs because of too much blood that flows in the penis. It often results from rupture of artery in the penis resulting in inability to enter the circulation.
Stuttering or recurring occurs on and off. Stuttering is usually painful.
Nocturnal priapism occurs during night time and may disturb the person from sleep.
Symptoms of priapism include:
- Prolonged erection of more than 4 hours
- Prolonged erection is the classical sign of priapism. Although the exact number of hours is still under debate, a significantly prolonged erection is a characteristic of priapism. The penis normally erects because of vasodilatation of the blood vessels in the penis during stimulation, but normally returns to its flaccid, non-erected state. However, in priapism, there is inability to return the blood in the circulation, or there is more blood that rushes in, leading to prolonged erection.
- Erection without sexual stimulation or there is persistent stimulation, despite the discontinuance of stimulation
- The erection of the penis is normally stimulated by both physical and psychological stimulation. When the stimulation is removed, the erection usually subsides and the penis goes back to its flaccid state. However, there is sustained erection in priapism not directly related to stimulation.
- Rigid shaft of the penis
- Because of intense erection, the shaft becomes very rigid. However, some types of priapism do not result to which.
- Can be painful or painless
- Ischemic priapism results in painful penis because of increased amount of blood that stays in the penis, which is not able to circulate in the body. Non-ischemic priapism on the other hand, is not painful because there is only increased amount of blood that circulates in the area, but is still able to drain in the venous circulation.
The causes are mainly related to neurovascular problems. These conditions may include:
Diseases that affect the circulation such as sickle cell disease, thalassemia, Fabry disease and leukemia may cause priapism because of sluggish blood flow resulting from the viscous blood. Because of this, the blood may not be able to escape from the blood vessels in the penis.
Problems such as spinal cord lesions and spinal cord trauma because of over stimulation of the autonomic nervous system, the one responsible for penile erection, may cause priapism.
A deficiency in glucose-6 phosphate dehydrogenase leads to low levels of NADPH, a co-factor responsible for the synthesis of nitric oxide. When nitric oxide is reduced, there will be prolonged erection.
Increased Adenosine Levels
Adenosine is responsible for the dilation of blood vessels. When it is significantly increased, it may lead to dilation of the blood vessels in the penis leading to priapism.
Intake of medications such as papaverine alprostadil causes priapism as a side-effect. This medication is a treatment for erectile dysfunction. Other medicines may include anticoagulants, antihypertensive medications, antidepressants and antipsychotics. Use of illegal drugs such as marijuana and cocaine may also cause priapism.
Black widow spider bites
The injury may result in the affectation of the nervous system leading to priapism.
Medical history is the initial diagnostic tool. Other diagnostic tests for priapism include:
Blood gas measurement
This involves the collection of a blood sample in the penis. This checks the level of blood gases such as oxygen in the penile circulation.
The amount of red blood cells and platelets may also be taken to determine hematologic conditions such sickle cell disease and leukemia.
These are done to check the presence of illegal drugs in the blood.
A duplex ultrasonography is also done to assess the blood flow in the penis and may specifically determine the type of priapism, either ischemic or non-ischemic.
What is the Treatment?
Treatment regimen for priapism involves both medical and surgical interventions, which include:
- Pseudoephedrine is usually given to patients to constrict the blood vessels in the penis. Pseudoephedrine being an alpha agonist is a vasoconstrictor, thereby reducing the dilation in the area leading to priapism. Amphetamine drugs may also be given. Intracavernosal injection of phenylephrine may also be used when other medications are not effective. This involves the injection of phenylephrine in the corpus cavernosum in the penis and may involve hemodynamic monitoring because this drug may cause bradycardia, hypertension, arrhythmia and tachycardia.
- Beta-2 agonists
- Terbutaline may also be given to allow smooth muscle relaxation in the corpus cavernosum leading to reduced erection.
- Methylene blue
- Methylene blue is administered intracavernously, but should not be used as a treatment for recurrent priapism because it may lead to tissue necrosis in the penis.
Aspirating blood in the penis under local anesthesia is a possible medical emergency treatment to reduce the amount of blood in the penis.
Surgical shunts may also be created to allow the blood to flow from the erected corpus cavernosum to the corpus spongiosum in the penis, which allows venous return of blood. Distal shunts (Winter’s shunt) involve the creation of the shunt in the glans penis. Proximal shunts (Quackel’s shunt) on the other hand involve the surgical incision in the perineum.
Figure 2 – Surgical intervention for Priapism
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