Splenic Pseudoaneurysm: Arterial Pathology
A splenic pseudoaneurysm is an arterial condition involving the splenic artery, not a venous structure. 1, 2, 3
Pathophysiology and Definition
A pseudoaneurysm (also called false aneurysm) results from a focal, incomplete rupture of the arterial wall—specifically disruption of the intima and/or elastic lamina—allowing blood to escape into the arterial wall and creating a contained collection of blood surrounded by adventitia and perivascular tissues rather than all three normal arterial layers. 4 This distinguishes it from true aneurysms, which involve all three arterial wall layers (intima, media, and adventitia). 5
Clinical Context
Splenic artery pseudoaneurysms specifically involve the splenic artery, which is the arterial blood supply to the spleen. 1, 6, 7 The condition most commonly arises from:
- Pancreatitis (most common non-traumatic cause): Inflammatory erosion into the splenic artery 8, 7
- Trauma: Blunt or penetrating abdominal injury 1, 7
- Iatrogenic injury: Post-procedural complications 7
- Infection or infiltrative disease: Including malignancies like lymphoproliferative disorders 4
Why This Matters Clinically
The arterial nature of splenic pseudoaneurysms has critical implications for management:
- High rupture risk with catastrophic bleeding: Because these are high-pressure arterial lesions, rupture leads to life-threatening hemorrhage with mortality rates of 10-25% in non-pregnant patients. 2, 3
- Angioembolization is first-line treatment: The arterial anatomy makes these lesions amenable to endovascular intervention targeting the splenic artery. 1, 3, 6
- Contrast imaging shows arterial enhancement: On CT angiography or ultrasound with Doppler, these lesions demonstrate arterial flow patterns and enhancement, confirming their arterial origin. 4
Common Pitfall to Avoid
Do not confuse splenic pseudoaneurysms with venous varices or splenic vein thrombosis—these are entirely different pathologies. Splenic pseudoaneurysms require urgent arterial-directed therapy (angioembolization or surgery), whereas venous pathology requires anticoagulation or different interventional approaches. 1, 3