Priapism
Template:Short description Template:Infobox medical condition (new) Priapism is a condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended.<ref name=EM2017/> There are three types: ischemic (low-flow), nonischemic (high-flow), and recurrent ischemic (intermittent).<ref name=EM2017/> Most cases are ischemic.<ref name=EM2017/> Ischemic priapism is generally painful while nonischemic priapism is not.<ref name=EM2017/> In ischemic priapism, most of the penis is hard; however, the glans penis is not.<ref name=EM2017/> In nonischemic priapism, the entire penis is only somewhat hard.<ref name=EM2017/> Very rarely, clitoral priapism occurs in women.<ref name=Lehmiller2014>Template:Cite book</ref>
Sickle cell disease is the most common cause of ischemic priapism.<ref name=EM2017/> Other causes include medications such as antipsychotics, SSRIs, blood thinners and prostaglandin E1, as well as drugs such as cocaine.<ref name=EM2017/><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Ischemic priapism occurs when blood does not adequately drain from the penis.<ref name=EM2017/> Nonischemic priapism is typically due to a connection forming between an artery and the corpus cavernosum or disruption of the parasympathetic nervous system resulting in increased arterial flow.<ref name=EM2017/> Nonischemic priapism may occur following trauma to the penis or a spinal cord injury.<ref name=EM2017/> Diagnosis may be supported by blood gas analysis of blood aspirated from the penis or an ultrasound.<ref name=EM2017/>
Treatment depends on the type.<ref name=EM2017/> Ischemic priapism is typically treated with a nerve block of the penis followed by aspiration of blood from the corpora cavernosa.<ref name=EM2017/> If this is not sufficient, the corpus cavernosum may be irrigated with cold, normal saline or injected with phenylephrine.<ref name=EM2017/> Nonischemic priapism is often treated with cold packs and compression.<ref name=EM2017/> Surgery may be done if usual measures are not effective.<ref name=EM2017/> In ischemic priapism, the risk of permanent scarring of the penis begins to increase after four hours and definitely occurs after 48 hours.<ref name=EM2017/><ref>Template:Cite book</ref> Priapism occurs in about 1 in 20,000 to 1 in 100,000 males per year.<ref name="EM2017">Template:Cite journal</ref>
ClassificationEdit
Priapism is classified into three groups: ischemic (low-flow), nonischemic (high-flow), and recurrent ischemic.<ref name=EM2017/> The majority of cases (19 out of 20) are ischemic in nature.<ref name=EM2017/>
Some sources give a duration of four hours as a definition of priapism, but others give six. Per the University Hospital Schleswig Holstein, "The duration of a normal erection before it is classifiable as priapism is still controversial. Ongoing penile erections for more than 6 hours can be classified as priapism."<ref>C. VAN DER HORST, HENRIK STUEBINGER, CHRISTOPH SEIF, DIETHILD MELCHIOR, F.J. MARTÍNEZ-PORTILLO, K.P. JUENEMANN; {{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
In womenEdit
Priapism in women (continued, painful erection of the clitoris) is significantly rarer than priapism in men and is known as clitoral priapism or clitorism.<ref name="Lehmiller2014" /> It is associated with persistent genital arousal disorder (PGAD).<ref>Template:Cite book</ref> Only a few case reports of women experiencing clitoral priapism exist.<ref name="Lehmiller2014" />
Signs and symptomsEdit
ComplicationsEdit
Because ischemic priapism causes the blood to remain in the penis for unusually long periods of time, the blood becomes deprived of oxygen, which can cause damage to the penile tissue. Such damage can result in erectile dysfunction or disfigurement of the penis.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In extreme cases, if the penis develops severe vascular disease, the priapism can result in penile gangrene.<ref>Template:Cite journal</ref>
Low-flow priapismEdit
Causes of low-flow priapism include sickle cell anemia (most common in children), leukemia, and other blood dyscrasias such as thalassemia and multiple myeloma, and the use of various drugs, as well as cancers.<ref name="FernandesSouza2018"/> A genome-wide association study on Brazilian patients with sickle cell disease identified four single nucleotide polymorphisms in LINC02537 and NAALADL2 significantly associated with priapism.<ref>Template:Cite journal</ref>
Other conditions that can cause priapism include Fabry's disease, as well as neurologic disorders such as spinal cord lesions and spinal cord trauma (priapism has been reported in people who have been hanged; see death erection).
Priapism can also be caused by reactions to medications. The most common medications that cause priapism are intra-cavernous injections for the treatment of erectile dysfunction (papaverine, alprostadil). Other medication groups reported are antihypertensives (e.g. Doxazosin), antipsychotics (e.g., chlorpromazine, clozapine), antidepressants (most notably trazodone), anti-convulsant and mood stabilizer drugs such as sodium valproate.<ref>Template:Cite journal</ref> Anticoagulants, cantharides (Spanish Fly) and recreational drugs (alcohol, heroin and cocaine) have been associated. Priapism is also known to occur from bites of the Brazilian wandering spider.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
High-flow priapismEdit
Causes of high-flow priapism include:
- blunt trauma to the perineum or penis, with laceration of the cavernous artery, which can generate an arterial-lacunar fistula.<ref name="FernandesSouza2018"/>
- Anticoagulants (heparin and warfarin).
- Antihypertensives (i.e., hydralazine, guanethidine and propranolol).
- Hormones (i.e., gonadotropin releasing hormone and testosterone).
DiagnosisEdit
The diagnosis is often based on the history of the condition as well as a physical exam.<ref name=EM2017/>
Blood gas testing the blood from the cavernosa of the penis can help in the diagnosis.<ref name=EM2017/> If the low-flow type of priapism is present, the blood typically has a low pH, while if the high-flow type is present, the pH is typically normal.<ref name=EM2017/> Color Doppler ultrasound may also help differentiate the two.<ref name=EM2017/> Testing a person to make sure they do not have a hemoglobinopathy may also be reasonable.<ref name=EM2017/>
UltrasonographyEdit
Penile ultrasonography with Doppler is the imaging method of choice, because it is noninvasive, widely available, and highly sensitive. By means of this method, it is possible to diagnose priapism and differentiate between its low- and high-flow forms.<ref name="FernandesSouza2018">Originally copied from:
Template:Cite journal
CC-BY license</ref>
In low-flow (ischemic) priapism the flow in the cavernous arteries is reduced or absent. As the condition progresses, there is an increase in echogenicity of the corpora cavernosa, attributed to tissue edema. Eventually, changes in the echotexture of the corpora cavernosa can be observed due to the fibrotic transformation generated by tissue anoxia.<ref name="FernandesSouza2018"/>
In high-flow priapism normal or increased, turbulent blood flow in the cavernous arteries is seen. The area surrounding the fistula presents a hypoechoic, irregular lesion in the cavernous tissue.<ref name="FernandesSouza2018"/>
TreatmentEdit
Medical evaluation is recommended for erections that last for longer than four hours. Pain can often be reduced with a dorsal penile nerve block or penile ring block.<ref name=EM2017/> For those with nonischemic priapism, cold packs and pressure to the area may be sufficient.<ref name=EM2017/>
PseudoephedrineEdit
Orally administered pseudoephedrine is a first-line treatment for priapism.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Erection is largely a parasympathetic response, so the sympathetic action of pseudoephedrine may serve to relieve this condition. Pseudoephedrine is an alpha-agonist agent that exerts a constriction effect on smooth muscle of corpora cavernosum, which in turn facilitates venous outflow. Pseudoephedrine is no longer available in some countries.
AspirationEdit
For those with ischemic priapism, the initial treatment is typically aspiration of blood from the corpus cavernosum.<ref name=EM2017/> This is done on either side.<ref name=EM2017/> If this is not sufficiently effective, then cold normal saline may be injected and removed.<ref name=EM2017/>
MedicationsEdit
If aspiration is not sufficient, a small dose of phenylephrine may be injected into the corpus cavernosum.<ref name=EM2017/> Side effects of phenylephrine may include: high blood pressure, slow heart rate, and arrhythmia.<ref name=EM2017/> If this medication is used, it is recommended that people be monitored for at least an hour after.<ref name=EM2017/> For those with recurrent ischemic priapism, diethylstilbestrol (DES) or terbutaline may be tried.<ref name=EM2017/>
SurgeryEdit
Distal shunts, such as the Winter's,Template:Clarify involve puncturing the glans (the distal part of the penis) into one of the cavernosa, where the old, stagnant blood is held. This causes the blood to leave the penis and return to the circulation. This procedure can be performed by a urologist at the bedside. Winter's shunts are often the first invasive technique used, especially in hematologically induced priapism, as it is relatively simple and repeatable.<ref>Template:Cite journal</ref>
Proximal shunts, such as the Quackel's,Template:Clarify are more involved and entail operative dissection in the perineum where the corpora meet the spongiosum while making an incision in both and suturing both openings together.<ref>Template:Cite journal</ref> Shunts created between the corpora cavernosa and great saphenous vein called a Grayhack shunt can be done though this technique is rarely used.<ref>Template:Cite journal</ref>
As the complication rates with prolonged priapism are high, early penile prosthesis implantation may be considered.<ref name=EM2017/> As well as allowing early resumption of sexual activity, early implantation can avoid the formation of dense fibrosis and, hence, a shortened penis.
Sickle cell anemiaEdit
In sickle cell anemia, treatment is initially with intravenous fluids, pain medication, and oxygen therapy.<ref name=NIH2014/><ref name=EM2017/> The typical treatment of priapism may be carried out as well.<ref name=EM2017/> Blood transfusions are not usually recommended as part of the initial treatment, but if other treatments are not effective, exchange transfusion may be done.<ref name=NIH2014>Template:Cite book</ref><ref name=EM2017/>
HistoryEdit
Persistent semi-erections and intermittent states of prolonged erections have historically been sometimes called semi-priapism.<ref>Template:Cite journal</ref>
TerminologyEdit
The name comes from the Greek god Priapus (Template:Langx), a fertility god, often represented with a disproportionately large phallus.<ref>Template:Citation</ref><ref>Template:Cite journal</ref>
ReferencesEdit
External linksEdit
- Guideline on the Management of Priapism (2003) Template:Webarchive - American Urological Association website - The unabridged 275-page version of this guideline.
- Template:Commons category-inline