WHEN ERECTIONS WON'T QUIT: UNDERSTANDING THE CHALLENGES OF PRIAPISM

Priapism is a medical condition where the penis remains rigidly erect for an extended period without any proper sexual stimulation. It is generally defined as an erection lasting four hours or longer. There are three main types of priapism: ischemic, non-ischemic, and recurrent ischemic.

Among these types, ischemic priapism is considered a serious emergency and requires immediate medical attention. If not treated promptly, it can lead to damage in the penis, potentially causing complete and permanent erectile dysfunction.

Early intervention is crucial for the recovery of normal erectile function. Without timely treatment, the penile tissue may undergo necrosis (cell death) and eventually fibrosis (scar tissue formation), resulting in permanent erectile dysfunction. It is vital to seek medical help promptly if experiencing prolonged erections to prevent severe complications and ensure the best possible outcome.

This podcast aims to provide a comprehensive understanding of priapism, including its symptoms and how it develops. It also covers the available treatment options for managing this condition effectively.

Causes of priapism

The causes of priapism can be broadly divided into two categories: low flow (ischemic) and high flow (non-ischemic) priapism. Ischemic priapism occurs when there is a reduced blood flow out of the penis, leading to prolonged and painful erections. Some common causes of ischemic priapism include certain blood disorders like sickle cell disease and thalassemia, as well as conditions that promote blood clotting. Medications like erectile dysfunction drugs, certain antidepressants, and illicit drugs like cocaine have also been associated with causing ischemic priapism. In rare cases, priapism can be linked to malignancies in the male pelvis, where tumors block the outflow of blood or directly infiltrate the penis.

On the other hand, non-ischemic priapism is less common and often occurs due to direct trauma or injury to the penis. It can also be a result of iatrogenic injury during surgical procedures, congenital arterial abnormalities, or cancer. In some instances, the exact cause of non-ischemic priapism may remain unknown.

It's worth noting that while phosphodiesterase type 5 inhibitors (medications like sildenafil, tadalafil, and vardenafil used to treat erectile dysfunction) have been associated with priapism, they are relatively rare culprits. Antipsychotic medications and trazodone, used to treat depression, have a higher likelihood of causing priapism compared to these erectile dysfunction drugs.

Additionally, some rare causes of priapism include medication reactions, such as hydroxyzine and drotaverine, as well as certain health conditions like chronic myeloid leukemia, Covid-19, thalassemias, amyloidosis, scorpion stings, spider bites, spinal cord injuries, and the use of electronic cigarettes.

Overall, understanding the different underlying causes of priapism is crucial for effective management and treatment of this condition.

Priapism, a condition characterized by prolonged and painful erections, can have various underlying causes. One of the most common reasons for priapism is the use of intracavernosal drugs to treat erectile dysfunction, accounting for up to about two-thirds of cases.

Another significant cause is sickle cell disease, which is responsible for a large number of adult priapism cases, with rates ranging between 40% and 80%. Sickle cell-related priapism is more prevalent in African Americans and has two peak age groups of occurrence, one between ages 7 to 10 and another between 20 to 50 years. Younger individuals tend to experience priapism due to sickle cell disease, while medication side effects become a more common cause in older populations.

The overall incidence of priapism is estimated to be between 0.73 and 5.4 cases per 100,000 men per year. Priapism following intracavernous injection therapy for erectile dysfunction is reported to occur in approximately 1.3% to 5.3% of cases. Younger men and patients with neurogenic or psychogenic erectile dysfunction are more susceptible to priapism following this type of treatment.

Interestingly, priapism tends to occur more frequently in the summer. Approximately 13% of patients with priapism who seek medical attention at emergency departments require admission for further management. While priapism is primarily considered a condition affecting males, rare cases of clitoral priapism have also been reported.

Pathophysiology of priapism

The pathophysiology of priapism involves two main types: ischemic and non-ischemic priapism. Ischemic priapism, which is more common, occurs when the smooth muscles and arteries in the corpora cavernosa (the erectile tissues in the penis) relax, causing prolonged and rigid erections. The inability to reverse this relaxation leads to low arterial blood flow into the corpora cavernosa, resulting in a trapped blood situation that increases pressure within the penis. This causes tissue ischemia, hypoxia (lack of oxygen), and acidic conditions, leading to pain and potential tissue damage.

On the other hand, non-ischemic priapism happens when arterial blood flows into the corpora cavernosa without proper venous drainage. In this case, there is no tissue ischemia, and the condition is usually painless.

One of the critical components of normal erectile function is nitric oxide. Some cases of priapism, especially in individuals with sickle cell disease, may be caused by a defect in the regulation of nitric oxide in the corpora cavernosa.

Underlying causes of priapism include an excess of neurotransmitters, blockage of venous drainage from the corpora cavernosa (due to various factors such as sickle cell disease or leukemia), dysfunction or paralysis of normal detumescence (return to flaccidity), or prolonged relaxation of cavernosal smooth muscle due to the use or overdose of vasoactive medications.

Permanent structural changes in the penis start to occur after about 6 hours of priapism, with significant cellular damage starting after 24 hours. If the priapism lasts longer than 24 hours, there is a high risk of permanent erectile dysfunction (ED) due to fibrosis and damage to the smooth muscle tissue.

Recurrent priapism, also known as "stuttering priapism," is a less common form of priapism. It tends to be associated with sickle cell disease and, in rare cases, cannabis use. Recurrent priapism involves short periods of erectile rigidity, which gradually increase in duration. The exact cause of this type of priapism is not well understood but is believed to be related to intracavernosal regulatory issues involving phosphodiesterase type 5 and nitric oxide.

Non-ischemic priapism is much less common and usually occurs after trauma or injury, where a fistula forms between the cavernosal artery and the corpora cavernosa. Unlike ischemic priapism, non-ischemic priapism is not painful, does not typically require emergency medical care, and often resolves spontaneously in the majority of cases.

Priapism is a common complication in males with sickle cell disease, with a prevalence ranging from 35% to 45% among affected individuals. It is more prevalent in adult patients compared to those under 18 years old.

Sickle cell patients who experience priapism often have more severe disease, with increased chest pain episodes, cerebrovascular events, and higher rates of hemolysis (red blood cell breakdown). Hemolysis releases substances that reduce available nitric oxide, which is essential for normal erections. However, in sickle cell patients, the corporal smooth muscle may become hypersensitive to nitric oxide, leading to prolonged erections. Oxidative stress further exacerbates this effect.

The majority (over 95%) of priapism cases in sickle cell disease are of the ischemic type. The high pressure in the venous channels of the erectile tissues due to mechanical venous obstruction and dysfunction reduces venous return and leads to engorgement of the corpora cavernosa (erectile tissues) with minimal arterial inflow, similar to compartment syndromes in other parts of the body.

Stuttering priapism, a form of recurrent ischemic priapism, is relatively common in sickle cell patients. These episodes last for a few minutes to three hours and are often painful but typically resolve on their own. Repeated episodes of ischemic priapism can cause permanent penile damage and erectile dysfunction in up to 40% of affected patients.

Sickle cell priapism frequently occurs at night during REM sleep and upon waking. It is associated with nocturnal androgen-dependent erections. Anti-androgen therapy may be beneficial for some patients with recurrent priapism.

There is a separate rare disorder called nocturnal painful erections, where patients experience painful, abnormal erections that wake them up from REM sleep. This condition is not associated with priapism or erectile dysfunction but may be caused by various factors such as obstructive sleep apnea, neuroendocrine/neurotransmitter disorder, psychogenic issues related to anxiety and sleep deprivation, increased pain sensitivity during REM sleep, or ischemic penile compartment syndrome. Treatment for nocturnal painful erections involves medication therapy, such as baclofen or pregabalin, and addressing underlying causes like obstructive sleep apnea.

Treatment

The treatment and management of ischemic priapism require prompt action to achieve detumescence and prevent irreversible damage to the corpora cavernosa. Here is a summary of the management steps:

1. Initial measures: Treat any priapism episode lasting four hours or longer as an emergency. Focus on achieving detumescence. Oral therapies such as pseudoephedrine can be tried while waiting for more advanced interventions.

2. Aspiration and normal saline irrigation: Aspiration of the corpora cavernosa using a large diameter needle, butterfly, or angiocath can be done to remove stagnant blood. Normal saline irrigation is then performed to reoxygenate the corpora and enhance the response to intracavernosal injections.

3. Intracavernosal drug therapy: Diluted phenylephrine is the preferred first-line agent for intracorporeal injection. It needs to be injected every 3 to 5 minutes for up to about 1 hour or until full detumescence is achieved.

4. Surgical intervention: If medical therapy fails, surgical intervention may be required. Shunt procedures, such as the Winter, Ebbohoj, and Al-Ghorab procedures, can be performed to reduce corporal pressures and relieve pain. Penoscrotal decompression has been suggested as an alternative shunting procedure that avoids trauma to the glans.

5. Penile prosthesis placement: In cases of prolonged priapism (48 hours or more), where damage to the erectile tissue is likely irreversible, immediate placement of a penile prosthesis should be considered to prevent further complications.

6. Antithrombotic therapy: Some studies have suggested the use of antithrombotic therapy as an adjunct to shunting procedures to reduce recurrence rates, but more research is needed to confirm its efficacy and safety.

For recurrent or "stuttering" priapism, treatment goals are similar to ischemic priapism, with acute therapy aimed at achieving detumescence and chronic therapy focused on preventing recurrences. Medications such as baclofen, casodex, finasteride/dutasteride, gabapentin, hydroxyurea, LHRH agonists, phenylephrine, pseudoephedrine, and sildenafil can be used based on the individual case.

For patients with sickle cell disease, in addition to standard treatment for acute episodes of priapism, aggressive hydration, alkalinization, oxygenation, and pain control are required. Hydroxyurea prophylaxis and automated exchange transfusions are effective for managing recurrent priapism in sickle cell patients.

Non-ischemic priapism is generally managed conservatively, as there is a low risk of penile damage. The initial approach involves observation and supportive care, including the use of topical ice packs. Aspiration can be performed for diagnostic purposes, but it usually does not lead to complete detumescence. Sympathomimetic intracorporal injections and surgical shunts are ineffective and not recommended for non-ischemic priapism.

Spontaneous resolution is reported in up to 62% of cases, and some patients may maintain their ability to achieve and maintain an erection despite years of non-ischemic priapism. Many patients may prefer to avoid surgery due to the risk of erectile dysfunction.

If a surgical procedure is desired, the initial recommended approach is arteriography with selective arterial embolization or direct ligation of the dysfunctional cavernous artery fistula. Selective arterial embolization has a high success rate, with reported resolution rates as high as 89%. Micro-coils may be used for embolization as they have lower recanalization rates compared to other methods.

In cases where selective arterial embolization is not feasible or unsuccessful, a surgical approach may be considered. This involves corporal exploration, often with intraoperative Doppler ultrasound, to identify and address the cause of the non-ischemic priapism. Care must be taken to avoid inadvertent ligation of the cavernosal artery during surgery.

The management of non-ischemic priapism should be tailored to the individual patient's preferences and needs. Observation and conservative care are the primary approach, and intervention with embolization or surgery may be considered if necessary or desired by the patient.

Prognosis for priapism depends on various factors, including the duration of symptoms, underlying pathology, comorbidities, and patient age. The longer the priapism episode lasts, the poorer the outcome is likely to be. Long-term or permanent erectile dysfunction is a significant risk, especially in cases of prolonged priapism, despite receiving optimal treatment. Patients who have experienced one episode of priapism are also at risk for recurrent attacks.

Younger men with sickle cell disease should be educated about priapism early on, as rapid treatment can help minimize permanent damage and the risk of erectile dysfunction.

Complications of priapism may include long-term erectile dysfunction due to damage to the corpora cavernosal tissues caused by prolonged priapism. Glans necrosis is a very uncommon complication, and non-surgical options like cavernosum-spongiosum shunts with continuous irrigation of normal or heparinized saline have shown more success in treatment than immediate surgical excision.

Patient education and follow-up are crucial to ensure successful therapy. Patients at risk for recurrence should be prescribed one or more of the oral agents that have been identified as helpful in controlling recurrences. These may include medications such as bicalutamide, finasteride, sildenafil, baclofen, gabapentin, hydroxyurea (for sickle cell patients), phenylephrine, pseudoephedrine, and IM leuprolide, either alone or in combination.

Regular follow-up and adherence to prescribed treatments can help improve outcomes and prevent further episodes of priapism. Patients should be aware of the importance of seeking prompt medical attention if they experience symptoms of priapism to minimize potential complications and improve the prognosis.

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