What is a characteristic of splenic artery aneurysm?

Splenic Artery Aneurysm Characteristics

Splenic artery aneurysms can present with the double-rupture phenomenon, are more common in women (not males), can be multiple, and will likely continue to enlarge if left untreated.

Double-Rupture Phenomenon

Splenic artery aneurysms (SAAs) can present with a characteristic "double-rupture phenomenon," which occurs in approximately 25% of patients 1. This phenomenon consists of:

1. An initial small herald bleed that is temporarily self-contained
2. A subsequent major rupture with rapid intra-abdominal bleeding and hemorrhagic shock

This pattern is particularly dangerous as the initial symptoms may be mild and misleading, followed by catastrophic hemorrhage hours or days later.

Gender Distribution

• SAAs are more common in women, not men
• According to the ACC/AHA guidelines, splenic artery aneurysms are particularly prevalent in women 1
• In a study by Trastek, 87 out of 100 patients with splenic artery aneurysms were women 1
• The female predominance is likely related to hormonal factors, particularly during pregnancy when the risk of rupture significantly increases

Multiplicity

• SAAs can frequently be multiple rather than solitary
• According to clinical data, multiple SAAs are not uncommon - in one series, 12 out of 23 patients (52%) had multiple splenic artery aneurysms 2
• This contradicts option (c) which suggests SAAs are "seldom multiple"

Natural History and Progression

• SAAs will typically continue to enlarge if left untreated 3
• This progressive enlargement increases the risk of rupture over time
• The risk of rupture is particularly high for:
  • Aneurysms larger than 2 cm in diameter
  • Symptomatic aneurysms
  • Aneurysms in pregnant women or women of childbearing age
  • Aneurysms in liver transplant recipients

Clinical Significance and Mortality

The clinical importance of correctly identifying SAAs cannot be overstated:

• Mortality rate for ruptured SAAs in non-pregnant patients: 10-25% 1
• Mortality rate for pregnant women with ruptured SAAs: up to 70-95% 1, 4
• Fetal mortality rate following rupture during pregnancy: >90% 1, 4

Management Considerations

• Asymptomatic SAAs <2 cm may be observed with regular imaging surveillance

• Intervention is recommended for:

  • Symptomatic aneurysms
  • Aneurysms >2 cm
  • Aneurysms in pregnant women or women planning pregnancy
  • Enlarging aneurysms
  • All false aneurysms

• Treatment options include:

  • Endovascular therapy (embolization or stent grafting) as first-line approach
  • Surgical options including aneurysm excision, ligation, or splenectomy

Pitfalls to Avoid

1. Misdiagnosis: SAAs are often asymptomatic and may be misdiagnosed when presenting with vague abdominal pain
2. Delayed intervention: Waiting too long to treat high-risk aneurysms, especially in pregnant women
3. Size misconception: Assuming small aneurysms (<2 cm) are safe during pregnancy - up to 50% of ruptured SAAs during pregnancy are smaller than 2 cm 5
4. Gender assumption: Incorrectly assuming SAAs are more common in men, which may lead to missed diagnoses in women