The true prevalence of splenic artery aneurysm is unknown. Estimates vary widely from 0.2% to 10.4%, but generally it is the third most common site of intra-abdominal aneurysms after abdominal aorta and iliac arteries 1 2. Incidentally discovered splenic artery aneurysms are being diagnosed more frequent with wider use of cross-sectional imaging modalities 3.
Splenic artery aneurysm is about four times more common in females, yet the risk of its rupture is about three times more common in males 4.
Size of splenic artery aneurysms can range from 2 to 9 cm, but usually it is smaller than 3 cm. Those may be single or multiple and are most commonly involving the distal portion of the artery. Peripheral calcification is common, and mural thrombus may be present 5.
Aetiology remains unknown, but they have been associated with hypertension, portal hypertension, cirrhosis, liver transplantation, and pregnancy. Less commonly associated conditions may include arterial fibrodysplasia, arteritis, collagen vascular disease, alpha 1 antitrypsin deficiency, and inflammatory disorders 4.
Most splenic artery aneurysms are silent and are discovered in asymptomatic patients. More than 95 % of patients with non-ruptured splenic artery aneurysms were asymptomatic 4. Risk of rupture is close to 2–3% 6 and this risk increases with liver transplantation, portal hypertension, and pregnancy. A ruptured splenic artery aneurysm usually present by sudden onset of left upper quadrant abdominal pain followed by hemodynamic instability, and gastro-intestinal bleeding 7.
The so-called “double rupture” phenomenon occurs when initial spontaneous stabilization followed by subsequent sudden circulatory collapse is experienced. This is caused by initial bleeding collecting into the lesser sac then followed by flooding into the peritoneal cavity 8.
Left IVC anomaly (transposition of IVC) has an incidence of about 0.2 to 0.5 %. It results from persistence of left and regression of right supra-cardinal veins. On imaging there is single left sided IVC that joins the left renal vein and crossover as left renal vein (usually pre-aortic rarely retro-aortic) to join right renal vein forming normal right supra-renal IVC that reaches the right atrium as usual. This anomaly must be known as it may be misinterpreted as para-aortic adenopathy, may lead to difficult trans-jugular access to infra-renal IVC filter placement 9 10.