Priapism

Definitions:

• An erection which continues for more than four hours, unrelated to sexual interest or stimulation
• A persistent or prolonged erection in the absence of sexual stimulation, which fails to subside

Rare – approx. 1 – 5 cases / 100 000 men / year

 

Pathology

Failure of the veno-occlusive mechanism to reverse after completion of sexual activity, and therefore persistent trapping of blood in the sinusoids.

This leads to time dependent changes in the corporal environment – leading to acidosis, hypoxia and hypercarbia.

Can be conceptualised as a compartment syndrome of the penis. Prolonged stagnation of old blood leads to ischaemia of the corporal tissue.

Histologically:

• Interstitial oedema of corporal bodies at 12 hours
• Endothelial cell destruction and thrombosis at 24 hours
• Smooth muscle necrosis and fibroblast proliferation at 48 hours

Subsequent cavernosal fibrosis results in permanent erectile dysfunction, shortening and deformity.

 

Risk factors

Haematological	Drugs	Malignancy	Neurologic	Trauma
Sickle cell Thalassaemia Myeloma Leukaemia “Blood dyscrasias”	Caverject, trimix etc Herbal remedies Illicit stimulants Ritalin Anticoagulants Lipid-rich TPN	Penile cancer Prostate cancer Pelvic metastases	Spinal cord injury Cauda equina Spinal cord stenosis	Pelvic trauma Perineal trauma Iatrogenic

 

Sickle cell reportedly accounts for a third of priapism worldwide. 40 % of men with sickle cell with have at least one episode of priapism.

Trauma may include straddle injuries, coital injuries – more associated with non ischaemic priapism.

 

 

Classification

Ischaemic (low flow)

• > 95 % of cases
• Painful
• Full rigidity and tenderness of corpora without glans
• Pathology as above – analogous to compartment syndrome

Non-ischaemic (high flow)

• Unregulated cavernous arterial inflow – disruption of the cavernous arterial anatomy creating an arteriolar-sinusoidal fistula
• Not an emergency – corpora still receiving oxygenated blood
• Typically non painful
• Usually a history of trauma

Stuttering (recurrent ischaemic)

• Repeated ischaemic priapism events, although often lasting less than four hours
• Often nocturnal
• Usually associated with sickle cell

 

Assessment

The aim of assessing the patient is to determine whether this is ischaemic priapism or not, as ischaemic priapism needs to be managed as a time-critical emergency.

History:

• Duration of symptoms
• Baseline erectile function
• Level of pain
• Medication or drug use
• Previous episodes of priapism and treatment
• Known haematological disorders or sickle cell
• History of trauma
• Other medical and surgical history including medications

 

Examination:

• Abdominal, genital, perineal and rectal if indicated
• Ischaemic priapism typically rigid corpora with soft glans
• Non ischaemic typically tumescent but not rigid
• Look for evidence of perineal or other trauma
• Pelvic mass / undiagnosed malignancy

 

 

Investigations:

• Full blood count (+/- sickle cell screen)
• Penile blood gas
  • Will confirm ischaemic vs non ischaemic (colour useful)
  • Ischaemic – acidotic (pH < 7.25), hypoxia, hypercapnia, raised lactate
• Doppler ultrasound
  • Absence of flow into cavernosal arteries typical of ischaemic priapism
  • High peak systolic velocities seen in non-ischaemic priapism
  • May demonstrate cavernosal arterial fistulas or pseudoaneurysms in non-ischaemic priapism
  • May be useful to confirm success of treatment
  • Overall rarely needed
• MRI
  • Not routinely used
  • Has been reported to confirm smooth muscle necrosis accurately in prolonged cases – and therefore may guide decision to early penile prosthesis placement

 

Management of ischaemic priapism

 

1. Confirm diagnosis with assessment as above.

If ischaemic priapism – manage as emergency.

 

2. Counselling

Patients must be counselled that ED is the natural history of untreated priapism, and that the aim of treatment is to attempt to prevent that.

ED may still occur after successful treatment and is dependent on the duration of priapism.

Baseline erectile function needs to be documented, and clear counselling should be documented especially in cases of delayed presentation.

Conservative measures including exercise, ejaculation, cold showers, ice packs and cold water enemas have been described but never backed up by evidence.

 

3. Aspiration +/- irrigation

Penile block – mixture of lignocaine and bupivacaine.

19 G needle/cannula through lateral corpora towards base (alternate is through glans).

Aspiration of blood (send some for gas).

May require irrigation with saline to allow aspiration of old clotted blood. Continue aspiration until bright red blood returned. Can use 2 x cannulas to speed up process and allow simultaneous irrigation and aspiration.

Approx 30 % success ?

 

4. Intracavernosal alpha agonist

Ensure cardiac monitoring with heart rate and blood pressure.

Phenylephrine is a selective alpha-1 agonist which stimulates smooth muscle constriction and arteriolar vasoconstriction. Being selective should reduce rate of adverse effects.

• Should be made up into a 200 microgram / mL solution. (typically comes in 10 mg in 1 mL – so make it up with 49 mL of saline)
• Inject 200 microgram aliquots, which can be repeated every 5 minutes until a maximum dose of 1000 micrograms / 1 mg.
• Potential risks including blood pressure lability, hypertension and coronary vasospasm – all rare.
  • Risk increases in patients taking monoamine oxidase inhibitors (MAOIs)

Alternative agent is adrenaline which is widely available and may be more easily accessible.

• 1 mg adrenaline into 1000 mL saline = 1 ug / mL
• Use 2 – 5 mL aliquots

EAU guidelines mention etilephrine and methylene blue (cGMP inhibitor) as having been successful in case series.

 

5. Surgical management / shunts

 

Indicated when corporal aspiration and instillation of sympathomimetics has failed. Shunts are more likely to be necessary when priapism has been prolonged (> 24 – 48 hours).

Goals of surgical intervention are:

• Allow outflow of stagnant, deoxygenated blood
• Restoration of normal inflow of oxygenated blood
• Pain relief

 

Distal percutaneous shunts

Winter – core biopsy needle through glans into corpora

Ebbehoj – multiple passes of 11 blade through glans into corpora

T-shunt – 10 blade into corpora through glans vertically, then 90 degree rotation laterally away from urethra. Initially unilateral, can proceed to bilateral if needed.

 

Open distal shunts

Al-Ghorab – open bilateral excision of the conical tips of the corpora cavernosa via an incision in the glans. Transverse incision of the glans distal to coronal sulcus. Dissect to the rigid corpora via palpation and grab with a Moynihan then excise 5 mm diameter segment.

Burnett (Snake) – passage of Hegar dilators through corpora (can also be done after T-shunt). Consider frog-leg position to allow to palpation of dilators in proximal corpora. Direct the dilators laterally (a la IPP).

 

For all distal shunt techniques, old blood should be expelled with compression via the shunt until fresh red blood is seen and detumescence achieved.

 

Proximal shunts

Quackel – corporospongiosal:

Perineal incision and opening of bulbospongiosus. Set up same for any perineal surgery i.e. lone star and hooks.

1 cm incision longitudinal into spongiosum and cavernosa separately. Avoid urethra (ensure catheter in place). Expel old blood from corpora.

Running 5-0 PDS to approximate cavernosa to spongiosum.

Can be repeated bilaterally if needed.

 

Greyhack – corporosaphenous

Dorsolateral longitudinal incision at base of penis. Dissection to tunica albuginea.

Vertical skin incision medial ipsilateral thigh at saphenofemoral junction (3 – 4 cm below and lateral to pubic tubercle). Saphenous vein is mobilised and ligated and freed from femoral vein. Ligate all the branches to the saphenous vein.

Bluntly dissect a tunnel between incisions and pass saphenous vein free end through. Excise a portion of tunica an ensure old blood expelled from corpora.

Spatulate the vein and anastomose with 6-0 PDS. Consider testing patency with heparinised saline.

 

Barry – corporodorsal (to dorsal vein).

 

Penoscrotal decompression (exposure a la IPP with tunnelling of the corpora through small corporotomies) is an emerging treatment for refractory priapism (failed distal shunts or > 48 hours). Some reported success with spontaneous erections.

 

Post-operative issues:

Post-operative rigidity – main goal is healthy arterial in-flow; check blood gas or Doppler, if healthy blood in-flow, no cause for concern.

There is some evidence the peri-operative anti-coagulation in the form of 325 mg pre-operative aspirin, 5000 units heparin intra-operatively and 5 days post-operative aspirin and clopidogrel reduces priapism recurrence after shunts.

 

EAU and BAUS guides suggest consideration of MRI if cases are prolonged 24 – 48 hours, as MRI has been shown to be strongly predictive of smooth muscle necrosis. If MRI suggests necrosis, or > 48 hours priapism, consider immediate placement of malleable prosthesis.

Earlier insertion of prosthesis (< 4 weeks) has lower complication rates (infection, shortening, revision) compared to late/delayed implants.

 

Management of stuttering priapism

A recurrent or recurring form of ischaemic priapism – initial work up and basic management is the same.

A variety of prophylactic medical measures are reported to have some success

• Pseudoephedrine orally
• Etilephrine (alternate alpha-agonist)
• LHRH agonists and antagonists (obvious side effects, avoid in pre-pubertal)
• Digoxin
• Terbutaline (b-agonist)
• Gabapentin
• Baclofen
• Hydroxyurea
• Low dose PDE5i can have a paradoxical beneficial effect. Start treatment when flaccid.
• Home PRN intracavernosal phenylephrine

Penile prosthesis is an option.

 

Management of non-ischaemic priapism

Some cases with resolve spontaneously without specific treatment.

Direct perineal compression and icepacks may help aid resolution.

Blood aspiration is not helpful as the problem is unregulated cavernous inflow.

Select arterial embolisation is indicated when conservative management fails – EAU suggests no definitive guidance can be made re: temporary or permanent substances for embolisation but then makes weak recommendation for temporary material first.

Repeated embolisation is safe and feasible. Risks include non target organ ischaemia (penile necrosis, gluteal ischaemia, perineal abscess).

Surgical ligation of fistula is rarely indicated and likely associated with high rates of iatrogenic ED.

 

 

 

 

 

EAU guideline for ischaemic priapism:

BAUS guideline: