Priapism: Pathogenesis



 - Post-cavernosal venous occlusion -> Post-cavernosal venous drainage is mechanically obstructed e.g. sickle cell disease, dialysis etc.

 - Increased nitric oxide from cavernous nerve plexus and cavernosal sinus endothelia -> Trabecular smooth muscle relaxes, Cavernosal artery smooth muscle relaxes -> Post-cavernosal venules are compressed against tunica albuginea

 - Impaired detumescence (erection-ending) pathways -> Lack of norepinephrine action on penile SM -> Trabecular smooth muscle and cavernosal artery smooth muscle do not contract



-> Ischemic (Low-flow): Inadequate venous function

-> Blood pools in corpora cavernosa

-> Increased pressure in corpora 

-> Priapism

Prolonged erection lasting more than 4 hours; in absence of sexual stimulation; not relieved by ejaculation



#Priapism #Pathophysiology #Urology #Diagnosis