What is the recommended treatment for a splenic aneurysm?

Management of Splenic Artery Aneurysms

Splenic artery aneurysms greater than 2 cm in diameter, symptomatic aneurysms, or those in women of childbearing age should be treated with endovascular therapy as the first-line approach. 1, 2

Epidemiology and Risk Assessment

• Splenic artery aneurysms (SAAs) are the most common visceral artery aneurysms, representing approximately 60% of all visceral aneurysms 1
• Risk factors for development include:
  • Portal hypertension
  • Cirrhosis
  • Pregnancy
  • Female gender
  • Multiple pregnancies

Clinical Presentation

• Most SAAs are asymptomatic and discovered incidentally on imaging
• Approximately 20% of patients present with symptoms including:
  • Chronic upper abdominal pain
  • Acute rupture with hemodynamic instability
• Rupture risk is significantly higher in:
  • Pregnant women (maternal mortality up to 70%, fetal mortality >90%) 1
  • Aneurysms >2 cm in diameter 2, 3
  • Symptomatic aneurysms
  • Women of childbearing age
  • Liver transplant recipients 2

Diagnostic Approach

• CT scan with intravenous contrast is the gold standard for diagnosis 1
• MRI offers similar sensitivity and specificity (90-95%) 1
• Doppler ultrasound and contrast-enhanced ultrasound are useful for follow-up 1

Treatment Algorithm

Indications for Intervention:

1. Symptomatic aneurysms (regardless of size)
2. Aneurysms ≥2 cm in diameter
3. Any size aneurysm in:
   • Pregnant women
   • Women of childbearing age
   • Liver transplant recipients
4. Enlarging aneurysms on surveillance
5. All false aneurysms (pseudoaneurysms)

Treatment Options:

1. Endovascular Treatment (First-Line) 2, 4, 5:

   • Transcatheter embolization with coils
   • Stent grafting
   • Advantages: Minimal invasiveness, shorter hospital stay (median 8 days vs 16 days for surgery), comparable long-term outcomes to surgery 5
   • Technical success rate approaches 100% 5

2. Surgical Treatment:

   • Reserved for:
     • Failed endovascular treatment
     • Ruptured aneurysms with hemodynamic instability
     • Complex anatomy not amenable to endovascular repair
   • Options include:
     • Aneurysmectomy with splenectomy
     • Aneurysm ligation with or without splenectomy
     • Splenic preservation should be attempted when possible 1

3. Conservative Management:

   • Appropriate for:
     • Asymptomatic aneurysms <2 cm in low-risk patients
     • Patients with prohibitive surgical risk
   • Requires regular imaging surveillance (typically every 6-12 months)

Special Considerations

Pregnancy

• SAA rupture during pregnancy carries extremely high maternal (70%) and fetal (>90%) mortality 1
• 50% of SAAs that rupture during pregnancy are <2 cm 1
• Prophylactic treatment recommended for any SAA detected during pregnancy 1
• "Double rupture phenomenon" may occur: initial small contained hemorrhage followed by catastrophic bleeding 1

Ruptured SAA

• Presents with abdominal pain, hypotension, and shock
• Requires immediate resuscitation and intervention
• Endovascular treatment if patient is stable enough; otherwise, emergency surgery 4

Follow-up

• Patients treated with endovascular techniques should undergo imaging follow-up to assess for recanalization
• For conservatively managed aneurysms, regular imaging surveillance is required to monitor for growth
• No evidence of aneurysm recurrence has been observed in properly treated cases 5

Pitfalls and Caveats

• Calcification of aneurysms does not protect against rupture 3
• Beta-blockers may have a protective effect against rupture 3
• Growth rates of SAAs are typically slow, but regular surveillance is still necessary 3
• Don't underestimate small aneurysms (<2 cm) in high-risk populations, especially pregnant women, as 50% of ruptured aneurysms during pregnancy are smaller than 2 cm 1