Splenic Artery Aneurysm: Symptoms, Types, Causes and Treatment

Splenic artery aneurysm (SAA) is an uncommon but potentially life-threatening condition. Despite its rarity, it is the third most common abdominal aneurysm and is being diagnosed more frequently due to advances in imaging technology. Early recognition and treatment are crucial, as rupture can be fatal. This article explores the symptoms, types, causes, and treatment options for splenic artery aneurysm, synthesizing the latest evidence from clinical research.

Symptoms of Splenic Artery Aneurysm

Splenic artery aneurysms can be silent for years, making early detection challenging. When symptoms do occur, they may be subtle or dramatic, often mimicking other abdominal conditions. Recognizing these clinical features is crucial for timely intervention and improved outcomes.

Symptom	Description	Frequency/Significance	Source(s)
Abdominal Pain	Dull, localized, often epigastric or flank	Most common symptom	1 4 2
GI Bleeding	Hematemesis, melena, or shock	Severe cases, risk of rupture	1 2 4 11
Asymptomatic	No symptoms, incidental imaging finding	Common, especially early	3 5 14 16
Shock/Collapse	Sudden hypotension, collapse	Rupture, life-threatening	2 4

Table 1: Key Symptoms

Symptom Presentation

Splenic artery aneurysms are often dubbed "silent killers." Up to half of cases are discovered incidentally during imaging for unrelated reasons, as most SAAs do not cause symptoms until they enlarge or rupture 3 5 14 16. When symptoms are present, they typically include:

• Abdominal or Flank Pain: This is the most frequently reported symptom, particularly localized to the left upper quadrant or epigastrium. Pain may be intermittent and nonspecific, sometimes mistaken for gastritis, pancreatitis, or peptic ulcer disease 1 2 4.
• Gastrointestinal (GI) Bleeding: In cases where the aneurysm erodes into the stomach or adjacent organs, patients may present with hematemesis (vomiting blood) or melena (black, tarry stools). GI bleeding can be chronic and subtle, or, more dangerously, sudden and massive, leading to hypovolemic shock 2 4 11.
• Shock/Collapse: Rupture is a catastrophic event, marked by sudden severe abdominal pain, hypotension, and collapse. This can be rapidly fatal without immediate intervention 2 4.
• Incidental Finding: Increasingly, SAAs are detected via ultrasound or CT scans performed for unrelated reasons, with patients remaining entirely asymptomatic 3 5 14 16.

Diagnostic Challenges

The nonspecific nature of SAA symptoms often leads to misdiagnosis or delayed diagnosis. For example, patients with minor GI bleeding may not undergo advanced imaging until bleeding recurs or worsens. In rare instances, splenic artery aneurysm may be suspected only after multiple negative endoscopies and persistently unexplained symptoms 2.

Types of Splenic Artery Aneurysm

Understanding the different types of SAA helps guide management and predict risk of complications. SAAs are generally classified based on their structure, location, and etiology.

Type	Description	Risk/Prevalence	Source(s)
True	Involves all layers of artery wall	60% of SAAs, more in women	7 11 3
Pseudoaneurysm	Disruption of one or more arterial layers	More prone to rupture, rare	1 8 14
Giant	≥5 cm in diameter	Rare, higher rupture risk	11 12
Anatomic Variants	At origin, distal, or aberrant locations	Alters treatment strategies	6 12 17

Table 2: SAA Types

True vs. Pseudoaneurysm

• True aneurysms involve all three layers of the arterial wall (intima, media, and adventitia). They account for about 60% of all SAAs and are more common in women, particularly in association with pregnancy or portal hypertension 7 11 3.
• Pseudoaneurysms (false aneurysms) result from disruption of the arterial wall, often due to trauma, pancreatitis, or iatrogenic injury. The wall of a pseudoaneurysm is formed by surrounding tissues rather than the normal artery wall, making rupture more likely. While rare, pseudoaneurysms demand urgent attention 1 8 14.

Size and Location

• Giant aneurysms are defined as those measuring 5 cm or more in diameter. These are extremely rare but carry a much higher risk of rupture and complications 11 12.
• Anatomic Variants include aneurysms at the arterial origin, distal third, or arising from aberrant splenic arteries. These variations complicate surgical or endovascular repair, requiring individualized approaches 6 12 17.

Special Considerations in Pregnancy

SAAs are four times more common in women, particularly of childbearing age. The risk of rupture increases dramatically during pregnancy, with maternal mortality rates of 65-75% and fetal mortality exceeding 90% 7 11. This makes prompt recognition and management in pregnant patients especially critical.

Causes of Splenic Artery Aneurysm

Identifying the underlying cause of a splenic artery aneurysm is essential for risk assessment and management. While some risk factors are well-known, others are emerging as more cases are studied.

Cause	Mechanism/Association	Relative Frequency	Source(s)
Pregnancy	Hormonal/flow changes, arterial wall stress	High in women	7 11 5
Portal Hypertension	Increased splanchnic pressure	Common comorbidity	10 11 15
Pancreatitis	Enzymatic injury, inflammation	Key cause of pseudoaneurysm	1 5 8
Trauma	Direct injury, iatrogenic	Pseudoaneurysm driver	1 8
Atherosclerosis	Medial degeneration, rare in SAA	Less common	3 10 11
Liver Transplant	Vascular changes post-surgery	High risk population	5 11
Genetic Disorders	E.g., Gaucher disease	Rare, underreported	9

Table 3: SAA Causes

Major Risk Factors

• Pregnancy: Hormonal changes and increased blood flow during pregnancy can weaken the arterial wall, predisposing women to SAA formation. The risk is especially high in the third trimester and with multiple pregnancies 7 11 5.
• Portal Hypertension: Increased pressure in the portal venous system, often due to liver cirrhosis or transplantation, is strongly linked to SAA development. These patients are at increased risk of both formation and rupture 10 11 15.
• Pancreatitis: Both acute and chronic pancreatitis can erode the wall of the splenic artery, leading to pseudoaneurysm formation. This is a particularly dangerous situation due to the high risk of rupture 1 5 8.
• Trauma and Iatrogenic Injury: Direct abdominal trauma or procedures involving the pancreas or spleen can damage the artery, resulting in pseudoaneurysms 1 8.
• Atherosclerosis and Medial Degeneration: Although less common than in other arteries, degenerative changes can still contribute to SAA formation, particularly in older adults 3 10 11.
• Liver Transplantation: Changes in splanchnic circulation following liver transplantation can increase risk, warranting screening in this population 5 11.

Rare and Emerging Causes

• Genetic Disorders: Rare conditions like Gaucher disease may predispose to visceral aneurysms, including SAA, possibly due to vascular involvement of the disease process 9.
• Other Factors: Multiple pregnancies, splenomegaly, medial hyperplasia, and even idiopathic (unknown) causes have also been described 1 11.

Pathophysiology Overview

The mechanism behind aneurysm formation involves a combination of factors that weaken the arterial wall—whether from increased pressure (as in portal hypertension), hormonal changes, enzymatic digestion (pancreatitis), or direct injury. Pseudoaneurysms are particularly dangerous as they lack a true wall, making rupture more likely and requiring urgent intervention 1 8.

Treatment of Splenic Artery Aneurysm

The management of SAA has evolved dramatically, with endovascular techniques now often preferred over open surgery. Treatment decisions depend on aneurysm size, symptoms, risk factors, and patient status.

Treatment	Indication	Pros/Cons	Source(s)
Endovascular	First-line for most SAAs	Minimally invasive, low mortality; may need reintervention	5 6 8 13 14 15 16
Open Surgery	Rupture, failed endovascular, complex cases	Definitive, higher peri-op risk	1 4 6 13 17
Laparoscopic	Selected, accessible aneurysms	Spleen-sparing, technical limits	17
Conservative	Small, asymptomatic, low-risk patients	Avoids intervention risk, requires close follow-up	5 8 13

Table 4: SAA Treatment Options

When to Treat

Not all SAAs require immediate intervention. Treatment is generally recommended for 5 11:

• Symptomatic aneurysms (pain or bleeding)
• Aneurysms >2 cm in diameter
• Aneurysms in women of childbearing age or during pregnancy
• Rapidly enlarging aneurysms
• All pseudoaneurysms, regardless of size or symptoms

Small, asymptomatic true aneurysms in low-risk patients may be monitored with periodic imaging 5 8 13.

Endovascular Treatment

Endovascular procedures, such as coil embolization or stent-graft placement, are now the first-line therapy for most patients 5 6 8 13 14 15 16. Advantages include:

• Minimally invasive, often under local anesthesia
• Lower perioperative mortality (0.5–0.6%) compared to open surgery (4.9–5.1%) 13 8
• Effective aneurysm exclusion, spleen often preserved 14 16

Challenges: Some aneurysms (e.g., those with complex anatomy or near the artery’s origin) may be technically difficult; in such cases, open surgery may be preferred 6 17.

Open and Laparoscopic Surgery

• Open Surgery: Still indicated for ruptured aneurysms, failure of endovascular treatment, or giant/complex lesions. Involves aneurysmectomy, sometimes with splenectomy or distal pancreatectomy. Perioperative risk is higher, but long-term outcomes are excellent 1 4 6 13 17.
• Laparoscopic Surgery: Increasingly used for accessible, non-ruptured aneurysms. Offers shorter recovery and less morbidity, though technical expertise and case selection are important 17.

Conservative Management

Selected small, asymptomatic aneurysms can be monitored with serial imaging, especially in patients with high surgical risk. However, careful follow-up is essential, as some aneurysms may enlarge or become symptomatic over time 5 8 13.

Special Populations & Complications

• Pregnant Patients: Given the high rupture risk, all SAAs in women who are pregnant or planning pregnancy should be treated, regardless of size 7 11.
• Complications: Post-treatment complications can include splenic infarction, pancreatic fistula, or abscess. Most can be managed conservatively or with minimally invasive techniques 3 13 14.

Conclusion

Splenic artery aneurysm is a rare but potentially devastating vascular condition. Its elusive symptoms, diverse causes, and evolving treatments require a high index of suspicion and a multidisciplinary approach for optimal outcomes.

Summary of Main Points:

• Symptoms can range from silent to catastrophic, with abdominal pain and GI bleeding most common.
• Types include true aneurysms, pseudoaneurysms, giant aneurysms, and those with anatomical variants.
• Causes are multifactorial, including pregnancy, portal hypertension, pancreatitis, trauma, liver transplantation, and rare genetic conditions.
• Treatment is individualized: endovascular therapy is now first-line, open or laparoscopic surgery reserved for select cases, and conservative management is possible with careful monitoring.

Prompt identification and appropriate management are critical to prevent rupture and improve patient survival. Advances in imaging and minimally invasive treatment have revolutionized care, but awareness among clinicians remains key to saving lives.