Priapism

Question 1

What is priapism?

Answer 1

Prolonged unwanted erection (> 4 hours), often painful and not associated with sexual arousal

Question 2

What are some causes of priapism?

Answer 2

• Intracorporeal injection for ED e.g. papavarine
• Trauma (penile/perineal)
• Haematological dyscrasias e.g. sickle cell
• Neurological conditions
• Idiopathic

Question 3

What are the 2 pathophysiological mechanisms of priapism?

Answer 3

Ischaemic (Veno-oclusive or low-flow)
Non-ischaemic - Less urgent

Question 4

Describe the pathophysiology of ischaemic priapism

Answer 4

• Vascular stasis in penis and decreased venous outlfow - a true compartment syndrome
• Corposa cavernosa are rigit and tender, penis often painful

Question 5

Describe the pathophysiology of non-ischaemic priapism?

Answer 5

• Traumatic distuption of penile vasculature results in unregulated blood entry and filling of corpora
• Fistula formation betweenc cavernous artrery and lacinar spaces allows blood to bypass the normal helicine arteriolar bed

Question 6

What investigations are required in priapism?

Answer 6

Aspirate blood from corpus cavernosum
Colour duplex USS

Question 7

What will be seen on blood aspiration from the corpus cavernosum in priapism?

Answer 7

• Dark blood, low O2 and high CO2 in low-flow
• Normal arterial blood in high-flow

Question 8

What will be seen on colour duplex USS in priapism?

Answer 8

• Minimal or absent flow in cavernosal arteries in low-flow
• Normal to high flow in non-ischaemic priapism

Question 9

How is ischaemic priapism managed?

Answer 9

• Aspiration +/- irrigation with saline
• If fails to resolve - injection of ⍺-agonist e.g. phenylephrine
• If fails to resolve - surgical shunt

Question 10

How is delayed presentation of priapism managed?

Answer 10

• Ischaemic priapism > 48-72 hours unlikely to respond to intracavernosal treatment
• For very delayed presentation, may even consider immediate placement of a penile prosthesis

Question 11

How is non-ischaemic priapism managed?

Answer 11

• Observe, may resolve spontaneously
• Selective arterial embolization with non-permanent materials