Splenic Artery Aneurysms

Epidemiology and Classification of Visceral Aneurysms

Splenic artery aneurysms are the most common visceral artery aneurysms, accounting for approximately 60% of all visceral aneurysms 1
Hepatic artery aneurysms are the second most common, accounting for about 20% of visceral aneurysms 2
Superior mesenteric artery aneurysms represent only 6-7% of all visceral aneurysms 1
Celiac artery aneurysms account for approximately 4% of visceral aneurysms 2
Other visceral aneurysms make up the remaining 10% 2

Most splenic artery aneurysms are asymptomatic at the time of discovery, typically found incidentally during abdominal imaging 1
Approximately 20% of patients present with either chronic upper abdominal pain or acute rupture 1
Women of childbearing age are at particularly high risk for rupture, with maternal mortality rates as high as 70% and fetal mortality exceeding 90% 1
Female gender is a risk factor associated with splenic artery aneurysms, with a higher incidence in women 2
Pregnancy, especially in multiparous women, is a risk factor for splenic artery aneurysms 1

The mortality rate for ruptured splenic artery aneurysms in non-pregnant patients ranges from 10% to 25% 1
Rupture during pregnancy carries significantly higher risks with maternal mortality up to 70% 1
Aneurysms measuring at least 2.0 cm in diameter have been reported to rupture during pregnancy 1

An increasing number of splenic artery aneurysms are being discovered in women undergoing ultrasound evaluations during pregnancy 1

The technical success rate for catheter-based interventions ranges from 67% to 100% 3
Patients undergoing catheter-based intervention should be monitored closely for development of abdominal pain, which may indicate complications 3

Aneurysms ≥2 cm require intervention due to significantly increased rupture risk, with mortality rates of 10-25% in non-pregnant patients and catastrophically higher rates (up to 70% maternal and >90% fetal mortality) during pregnancy 4, 5
Growth of >0.5 cm per year is an indication for treatment, even if the aneurysm has not yet reached 2 cm, although this specific fact is not directly cited, a similar concept is mentioned in the context of high-risk populations 4, 5

All splenic artery aneurysms in pregnant women or women of childbearing age warrant treatment regardless of size, as rupture during pregnancy carries maternal mortality of 21.9-70% and fetal mortality of 15.6-90% 4, 5, 6
Critically, up to 50% of aneurysms that rupture during pregnancy are <2 cm in diameter, making size-based criteria unreliable in this population 6, 7
The risk is highest in the third trimester when splenic blood flow from hyperdynamic circulation is maximal 8
Prophylactic intervention pre-conception is appropriate for known aneurysms >2-3 cm or those with prior rupture history 8

Portal hypertension itself increases the risk of splenic artery aneurysm formation and rupture 6, 7

Approximately 20% of patients present with symptoms (chronic pain or acute rupture) rather than incidental discovery 4, 5

Trans-catheter embolization is the mainstay for acute rupture, with surgical ligation and splenectomy reserved for failed endovascular therapy 8

Pain may radiate to the left flank or back in patients with splenic artery aneurysm 9
The classic presentation of rupture includes abdominal pain with syncope and hemodynamic instability 9
Abdominal distension and peritoneal signs may occur in cases of intraperitoneal rupture 9

The greatest risk of splenic artery aneurysm rupture occurs in the third trimester of pregnancy when hyperdynamic circulation maximizes splenic blood flow 9
Pregnant women presenting with abdominal pain and syncope are at high risk of splenic artery aneurysm rupture 9
Maternal mortality reaches 70-95% and fetal mortality exceeds 90% in advanced rupture cases 9
Patients with cirrhosis and severe splenomegaly warrant attention for splenic artery aneurysm presence 9

The American Heart Association recommends endovascular coil embolization as the first-line treatment for splenic artery aneurysms when intervention is required, with technical success rates of 67-100% 10

The American College of Cardiology recommends intervention with open repair or catheter-based treatment for splenic artery aneurysms ≥2.0 cm in diameter in women of childbearing age and patients undergoing liver transplantation, and is probably indicated for all other patients regardless of gender 11
Imaging must document precise aneurysm diameter, location along the splenic artery, and presence of calcification, with CT angiography being the optimal imaging modality 12, 13, 14

The American College of Cardiology recommends immediate intervention for any symptomatic aneurysm, regardless of size, and for aneurysms ≥2.0 cm in high-risk populations, including women of childbearing age and patients undergoing liver transplantation 11
The American Heart Association recommends intervention for aneurysms ≥2.0 cm in all other patients, with a rupture mortality rate of 10-25% in non-pregnant patients and an operative mortality rate of 0% for elective intervention versus 38% for ruptured aneurysms 11, 12, 13, 14

The American College of Gastroenterology recommends transcatheter embolization as the primary therapeutic approach, with technical success rates of 67-100% and options including coil embolization alone or combined with cyanoacrylate 15
The American Heart Association recommends monitoring for post-procedure complications, including abdominal pain and fever, and reserving open surgical repair for failed endovascular therapy or anatomically unsuitable cases 14, 15

The American College of Cardiology recommends controlling hypertension aggressively in all patients with aneurysms, with beta-adrenergic blocking agents potentially reducing aneurysm expansion rates 16, 17, 18
The American College of Cardiology also recommends advising patients to stop smoking and offering smoking cessation interventions 16, 17, 18