Priapism

1. Priapism 31st March 2003 R Power

2. Definition • persistent erection not accompanied by sexual desire or stimulation • > 6 hours • Corpora cavernosa only • all age groups (including newborns) • peak incidence 20 to 50yrs • younger age group assoc with sickle cell • usually pain (except in non-ischaemic type)

3. Classification • Low flow or Ischaemic (veno-occlusive) • most common • Painful sec to tissue ischaemia and smooth muscle hypoxia (compartment syndrome) • Nonischaemic (arterial) • less common • upregulated cavernous inflow • usually not fully erect and painless

4. Low-flow priapism • Low flow or Ischaemic (veno-occlusive) • most common • Penis fully erect (sludging of blood within) • Painful sec to tissue ischaemia and smooth muscle hypoxia (compartment syndrome) • blood gases from corpora - acidosis •  NO & prostacyclin • platelet aggregation and adhesion - thrombus formation and tissue damage

5. Causes of low-flow priapism • Intracavernosal pharmacotherapy • 21% of cases of priapism - 207 patients papaverine (Nieminem et al.1995) • PGE-1 alprostadil • <1% intracavernosal • <0.1% intraurethral • extremely low incidence with oral agents • Drugs • cocaine, heparin withdrawal, trazadone, phenothiazines

6. Causes of low-flow priapism • Hyperviscosity syndromes (sickle-cell disease) • 28% of all cases of priapism (most common cause in children) • 42% incidence in adults with sickle-cell disease • 64% incidence in boys with sickle-cell disease • also affects with sickle-cell trait • ? Assoc with testosterone • Other haemoglobinopathies • thrombophilia • “stutter priapism” • Recurrent episodes of priapism can result in enlarged penis, fibrotic corpora and ED

7. Causes of low-flow priapism • Neurological causes • rare • lumbar disc lesions, spinal stenosis, seizure disorders, cerebrovascular disease • Post Trauma • perineum, groin or penis usually cause high flow priapism but can cause low flow sec to haematoma • Solid Tumours • malignant infiltration of corpora • Miscellaneous • TPN, amyloid , rabies, appendicitis

8. High-flow priapism • Nonischaemic (arterial) • less common • Penile, perineal or pelvic trauma • uncontrolled arterial inflow directly into the penile sinsoidal spaces • usually penis not fully erect and painless • often prolonged history • normal local blood gases • no risk of ischaemia and subsequent fibrosis

9. Causes of High-flow priapism • Trauma • Very rarely sickle-cell disease • Fabry`s disease

10. Management of Priapism • Urological emergency • Treat causal factor where identified • goal is to abort the erection, thereby preventing permanent damage to the corpora (ED) and to relieve pain. • Longer duration implies greater risk of impotence • principle is to restore arterial inflow and venous outflow • clinical history and drug history • glans and corpus spongiosum rarely involved • urinalysis • haemoglobin S to outrule leukaemia • ? Local blood gas measurments • radionucleotide scanning - no longer performed • colour doppler ultrasonography

11. Medical management of low-flow priapism • aspiration of the corpora with a 21G butterfly needle followed by an injection of phenylephrine (1 adrenergic agonist) every 5 minutes until detumescence • 10mg/ml phenylephrine in 19mls saline • 100% effective if within 12 hours • Oral terbutaline (-adrenoceptor agonist) - 5-10mg • at best 36% response • Sickle-cell - prompt and conservative as it recurs • hydration, oxygenation, metabolic alkalinization • aspiration and injection (as above) • Stuttering priapism • self injection of -adrenergic agent if sexually active (prophylactic digoxin) or oral -adrenergic agent (Etilefrine) • antiandrogen if not to suppress nocturnal tumescence

12. Surgical management of low-flow priapism • Winter procedure using a Trucut needle • create a shunt between glans and corpora cavernosa • Ebbehoi procedure using a pointed scalpel blade • El-Ghourab procedure • excision of a piece of tunica albuginea • 30% of above techniques fail • direct cavernosal-spongiosum anastomosis • corpora-saphenous shunt • lower incidence of ED reported with Winter technique • Intracavernosal thrombolytic agents ??

13. Management of High-flow priapism • Ice pack  arterial spasm • ?? spontaneous thrombosis • Most cases require arteriography and embolisation of the internal pudendal artery or a branch

14. Complications • Untreated low-flow priapism leads to corporal fibrosis and impotence • early complications: • acute hypertension, headache, palpitations, arythmias • bleeding, haematoma, infection and urethral injury • late complications: • fibrosis and impotence • related to duration of priapism and aggressivness of treatment • low-flow : high incidence of ED if not treated within 12 hours • high flow : good prognosis (20% rate of ED)