What is the management approach for a splenic artery pseudoaneurysm?

Management of Splenic Artery Pseudoaneurysm

Angioembolization should be the first-line treatment for splenic artery pseudoaneurysms when discovered, as they carry significant rupture risk and rarely resolve spontaneously, unlike post-traumatic pseudoaneurysms which may be observed in select cases. 1

Critical Distinction: Traumatic vs Non-Traumatic Pseudoaneurysms

The management approach differs fundamentally based on etiology:

Post-Traumatic Pseudoaneurysms (Pediatric and Adult)

• Most resolve spontaneously without intervention and can be observed with serial imaging in hemodynamically stable patients 1
• Angioembolization should be considered when pseudoaneurysm persists on pre-discharge imaging or if there are signs of persistent hemorrhage despite hemodynamic stability 1
• Ultrasound (Doppler or contrast-enhanced) follow-up is reasonable to monitor for delayed hemorrhage 1
• In pediatric patients, the vast majority do not require angioembolization even with moderate-to-severe injuries 1

Non-Traumatic Pseudoaneurysms (Pancreatitis, Idiopathic, Other)

• All non-traumatic splenic artery pseudoaneurysms should be treated regardless of size due to high rupture risk 2
• These are typically associated with chronic pancreatitis, present with bleeding or pain, and do not spontaneously resolve 3, 2
• Average diameter at presentation is smaller than true aneurysms (1.7 cm vs 5.0 cm), yet still require intervention 2

Treatment Algorithm by Clinical Presentation

Hemodynamically Unstable Patients

• Immediate resuscitation with blood products and urgent intervention 4
• Angioembolization is preferred as first-line therapy with technical success rates of 67-100% 5, 6
• Surgical intervention (splenectomy ± distal pancreatectomy) is reserved for failed endovascular therapy or when not feasible 1, 3
• Laparoscopic approaches should not be used in acute bleeding scenarios 1

Hemodynamically Stable Patients

• Transcatheter embolization remains the mainstay with lower complication rates than surgery 6
• Post-procedure imaging is mandatory to confirm complete obliteration 6
• EUS-guided coil and glue injection is an emerging alternative for pseudoaneurysms that failed angiographic embolization, with 100% success in small series 7

Special Populations Requiring Aggressive Treatment

Women of childbearing age or pregnant patients:

• All pseudoaneurysms warrant treatment regardless of size due to catastrophic rupture risk (maternal mortality 21.9-70%, fetal mortality >90%) 5
• Up to 50% of pregnancy-related ruptures occur in pseudoaneurysms <2 cm 5
• Prophylactic intervention pre-conception is appropriate for known lesions 5

Liver transplant candidates:

• Portal hypertension increases formation and rupture risk, necessitating treatment 5

Surgical Indications

• Hemodynamic instability despite resuscitation (>40 mL/kg blood products in 24h or >4 units) 1
• Failed angioembolization 1, 3
• Ruptured pseudoaneurysms typically require splenectomy or splenopancreatectomy, particularly when associated with pancreatitis 3, 2
• Splenic preservation should be attempted when feasible in non-ruptured cases 1

Post-Intervention Monitoring

• Close monitoring for abdominal pain indicating complications such as splenic infarction or post-embolization syndrome 5
• Post-embolization syndrome (fever, pain, ileus) occurs in up to 90% of pediatric cases but is self-limited 1
• Repeat imaging at 4 weeks to confirm complete occlusion 7
• For traumatic cases managed conservatively, ultrasound follow-up minimizes risk of delayed hemorrhage 1

Common Pitfalls

• Do not assume all splenic artery pseudoaneurysms behave like post-traumatic ones - non-traumatic pseudoaneurysms require intervention regardless of size 2
• Do not rely on size criteria alone in pregnant women - even small pseudoaneurysms can rupture catastrophically 5
• Do not delay intervention in symptomatic patients - bleeding or pain indicates high rupture risk 4, 2
• Ensure vaccination against encapsulated organisms if splenectomy is performed (pneumococcus, H. influenzae, meningococcus) starting ≥14 days post-operatively 1