Urology: Priapism

Priapism

Definition

  • Persistent Erection Not Associated with Sexual Stimulation or Desire
  • Most Common Definition: > 4 Hours
  • Generally Used to Describe Penile Priapism but Can Also Affect the Clitoris

Classification

  • Ischemic (Low-Flow/Anoxic) Priapism
    • Most Common
    • Due to Impaired Relaxation/Paralysis of the Corpus Cavernosum Smooth Muscles
    • Causes Compartment Syndrome in the Cavernous Tissue
    • Generally More Painful & Rigid
    • Urologic Emergency – Delay in Diagnosis Can Cause Permanent Damage/Necrosis
  • Non-Ischemic (High-Flow/Arterial) Priapism
    • Often Due to a Fistula Between the Cavernosal Artery & Corpus Cavernosum Caused by Trauma or Needle Injury
    • Generally Self-Limited
    • Generally Less Painful & Less Rigid
    • Not a Urologic Emergency – Cavernous Blood is Well Oxygenated

Recurrent (“Stuttering”) Priapism

  • A form of Ischemic Priapism Seen in Sickle Cell Disease
  • Recurrent Episodes – Start with Short Episodes that Become Increasingly Long/Frequent Until an Ischemic Priapism Event is Suffered

Causes

  • Primary/Idiopathic – Most Common
  • Secondary Causes:
    • Intracavernosal Injections
    • Medications – Anticoagulation, PDE5 Inhibitors, Antihypertensives, Antidepressants)
    • Cocaine
    • Sickle Cell Disease
    • Spinal Shock
    • Trauma
    • Infection
    • Malignancy

Diagnosis

  • Clinical Diagnosis
  • Important to Distinguish Ischemic from Non-Ischemic Etiology
    • Possibly Based on History & Exam
    • Cavernosal Blood Gas if Uncertain – Ischemia Has Black Blood with Hypoxia, Hypercarbia & Acidemia
    • Can Also Use Doppler US – Minimal-No Blood Flow in Ischemic Causes

Treatment

  • Ischemic Priapism: Rapid Detumescence
    • Corpus Cavernosum Aspiration (5 cc) & Irrigation to Drain Clots
    • Phenylephrine Injection Can Assist
    • May Require Repeated Aspirations/Injections
    • If Fails: Cavernoglandular Shunt
      • Incision to Create Channel Through Glans
    • Consider Exchange Transfusion (RBC Apheresis) for Sickle Cell Disease if All Other Measures Fail
  • Non-Ischemic Priapism: Observation
    • Angioembolization if Fails
    • Surgical Ligation if Angioembolization Fails