Diagnosis

Priapism

Etiology

Cause [z1m][ude][tcw][nbo]

1. Low-flow priapism (ischemic - 95%):

   • Ischemic:

     • Hemoglobinopathies (sickle cell disease, thalassemia), hypercoagulable state

     • Neoplasia (leukemia, melanoma, prostate cancer (blockage of venous outflow), renal cancer, bladder cancer, rhabdomyosarcoma, testicula)

     • Infection

     • Neurogenic (spinal cord injury, caudqa equina syndrome)

     • Toxins (malaria, scorpion, spider)

     • Henoch–Schönlein purpura

     • Hemodialysis

     • Parental nutrition

   • Drugs: Intracoporal Caverject (alprostadil) injections, alpha blockers, antihypertensives, cocaine, trazadone (antidepressant), antipsychotics, PDE5 inhibitors (Viagra), Hormones (testosterone)

   • Non-ischemic: Neurologic disorders, Fabry disease, dialysis, fat embolisms, cauda equina syndrome, amyloidosis, infections

   • Neonatal: Polycythemia, Infection (syphilis, pyocavernositis), Cranial birth trauma (forceps), Respiratory distress syndrome, Umbilical artery catheterization

2. High-flow priapism (nonischemic - 5%):

   • Arteriovenous (AV) fistula secondary to trauma or surgery

Pathophysiology [z1m]

• Ischemic:

  1. Nitric oxide --> smooth muscle relaxation of the tissues and arteries in the corpora cavernosa

  2. Venous trapping of blood (neurotransmitters, mechanical blockage, dysfunction of normal detumescence)

  3. Increased intracorporal pressure --> compartment syndrome

  4. Tissue ischemia, hypoxia, cavernosal acidosis, and penile pain.

• Non-ischemic high-flow priapism is caused by unregulated arterial blood flow into the corpora cavernosa without associated venous trapping

  • Not painful

  • Erection not fully turgid

  • Glans generally not engorged

Complications [z1m]

• Ischemic priapism

  • Long-term erectile dysfunction

  • Corporal fibrosis

  • Glans necrosis --> organ loss in severe cases

Epidemiology

Incidence per 100.000 [z1m][nbo][ude][skp][fzv]

Approach

• Blood test: full blood count, CRP, APTT, Psychoactive medication screening

• Urine toxicology

• Color Doppler ultrasonography: low-flow or high-flow?

• Aspirated Corporal Blood Gas: [z1m]

  • Ischemic: pH <7.2, pO2 < 30 mmHg, pCO2 > 60 mmHg, Glucopenia <3.5 mmol/L

  • Non-ischemic: pH >7.2), pO2 > 90 mmHg, pCO2 < 40 mmHg

Treatment

1. Neonates: [ude]

   • Ischemic priapism: Corporal aspiration and/or ketamine anaesthesia

   • Corporal injection with sympathomimetics

   • Polycythemia: Red cell volume reduction (venesection)

   • Idiopathic neonatal priapism: Careful observation, majority resolve spontaneously without sequele

2. Older children: Physical exercise, urination, a cold bath, ejaculation, and fluids

   Ischemic: [crb][nbo][z1m]

   • Oral pseudoephedrine

   • Penile local anesthetic block

   • Corporal aspiration and heparinized or normal saline irrigation

   • Corporal injection: 0.9% saline (1ml/kg) + phenylephrine 100-500 μg injection every 5 minutes for 5 doses

   • Bilateral distal T-shunts

   • Surgery: mid-corporal corporotomies ± "snake maneuver"

   • Penoscrotal decompression

   • Proximal shunt (Quackels shunt)

   • Penile prosthesis

   Non-Ischemic: majority show spontaneous resolution [crb][nbo]

   • Conservative: Color Doppler ultrasonography twice weekly for ≥6 weeks

   • Mechanical: intermittent compression

   • Anti-androgen hormonal agents

   • Embolisation: with dissolvable material (gelatine foam)

   • Surgical: trans-corporal fistula ligation

Differential diagnoses

Cellulitis, Cocaine toxicity, Drug side effects, Paraphimosis, Penile fracture, Periurethral abscess, Peyronie disease, Sickle cell disease, Spinal stenosis