What is the management approach for a small 0.8 cm peripherally calcified splenic artery aneurysm?

Management of Small 0.8 cm Peripherally Calcified Splenic Artery Aneurysm

For a small 0.8 cm peripherally calcified splenic artery aneurysm, observation with serial imaging surveillance is the appropriate management strategy, as aneurysms <2 cm in diameter have negligible rupture risk and grow at only 0.2 mm per year. 1, 2

Size-Based Treatment Threshold

• Splenic artery aneurysms ≥2 cm in diameter require intervention due to significantly increased rupture risk, with mortality rates of 10-25% in non-pregnant patients 3, 1, 4
• Aneurysms <2 cm, like this 0.8 cm lesion, can be safely observed as they carry negligible rupture risk and grow slowly at a mean rate of 0.2 mm per year 2
• In a large series of 128 patients, those with aneurysms <2 cm managed conservatively had no late aneurysm-related mortality over 10-year follow-up 2

Role of Calcification

• Peripheral calcification does NOT protect against rupture, contrary to older assumptions 1
• However, increased aneurysm calcification is associated with smaller aneurysm size, which itself correlates with lower rupture risk 2
• The calcification in this case should not be considered a protective feature that would change management decisions 1

Observation Protocol

• Serial imaging surveillance is recommended for aneurysms <2 cm 4, 5
• Imaging intervals should monitor for growth, with intervention considered if the aneurysm enlarges to ≥2 cm or grows rapidly 4, 2
• CT angiography is the optimal imaging modality for detailed vascular anatomy and size assessment 6
• Ultrasound can be used for surveillance if CT is contraindicated 6

Critical Exceptions Requiring Immediate Treatment (Even for Small Aneurysms)

Women of Childbearing Age

• Any splenic artery aneurysm in women of childbearing age warrants treatment regardless of size, as rupture during pregnancy carries maternal mortality of 70% and fetal mortality >90% 3, 1, 4
• Critically, up to 50% of aneurysms that rupture during pregnancy are <2 cm in diameter 3
• If this patient is a woman of childbearing age, prophylactic intervention should be performed even at 0.8 cm 1, 4

Symptomatic Presentation

• Any aneurysm causing chronic upper abdominal pain, left flank pain, or back pain requires treatment regardless of size 3, 4
• Approximately 20% of splenic artery aneurysms present symptomatically 6, 3

Liver Transplant Candidates

• Portal hypertension increases both formation and rupture risk of splenic artery aneurysms 3, 4
• Patients awaiting liver transplantation should undergo prophylactic treatment of aneurysms ≥2 cm 4, 5

Treatment Modalities (When Indicated)

• Endovascular coil embolization is the first-line treatment when intervention is required, with technical success rates of 67-100% 7, 6, 4
• Endovascular therapy results in mean 1.5 mm regression in aneurysm size over 2 years 2
• Open surgical ligation or splenectomy is reserved for failed endovascular therapy or acute rupture 3, 8
• Post-intervention monitoring for abdominal pain is mandatory to detect complications, as direct visualization of the spleen is not possible with endovascular approaches 6, 9

Common Pitfalls to Avoid

• Do not assume calcification provides protection against rupture - this is a dangerous misconception 1
• Do not defer treatment in women of childbearing age based on size alone - pregnancy dramatically increases rupture risk even for small aneurysms 3, 1
• Do not rely on physical examination alone - most splenic artery aneurysms are asymptomatic at discovery and found incidentally on imaging 6, 3
• After endovascular treatment, close monitoring is essential as rapid recanalization can occur, especially if distal coiling is unsuccessful 8