What are the causes of splenic infarcts?

Causes of Splenic Infarcts

Splenic infarction results primarily from thromboembolic events originating from cardiac sources, hematologic malignancies, and infectious processes, with the specific etiology varying significantly by patient age and clinical context.

Thromboembolic Causes (Most Common Overall)

Cardiac sources account for the majority of splenic infarcts, particularly in patients over 40 years of age [1, 2:

• Atrial fibrillation with left atrial thrombus formation is a leading cause 1
• Left ventricular dysfunction with poor ejection fraction and mural thrombus (particularly in dilated cardiomyopathy and acute myocardial infarction) 1
• Infective endocarditis with valvular vegetations—occurs in 40% of left-sided endocarditis cases, though only 5% progress to splenic abscess 3
• Prosthetic heart valves serving as embolic sources 1
• Atheromatous debris embolization from the aorta 1

Emboli typically lodge 3-10 cm distal to the origin of the superior mesenteric artery (SMA), and more than 20% of SMA emboli are associated with concurrent emboli to the spleen and kidney 4.

Hematologic Disorders (Predominant in Younger Patients)

In patients under 40 years old, hematologic disorders are the most common cause [5, 2:

• Sickle cell anemia—while small repetitive infarcts leading to autosplenectomy are typical, massive splenic infarction can occur, particularly with precipitating factors such as high altitude, postoperative states, postpartum period, salmonella septicemia, or strenuous exercise 6
• Hematologic malignancies including leukemias and lymphomas [2, 7
• Hypercoagulable states including Factor V Leiden, prothrombin mutation, protein S deficiency, protein C deficiency, antithrombin deficiency, and antiphospholipid syndrome 4

Infectious Causes

• Bacterial endocarditis—classically associated with splenic infarction, though less common in contemporary series (only 3 of 26 cases in one modern cohort) 2
• Epstein-Barr virus (EBV) infection with associated splenomegaly 8
• Sepsis-related processes 6

Vascular and Anatomic Causes

• Splenic artery thrombosis due to atherosclerotic disease 5
• Splenic vein thrombosis (mesenteric venous thrombosis)—accounts for less than 10% of mesenteric infarction cases and follows Virchow's triad 4
• Vasculitis affecting splenic vessels 4
• Mesenteric dissection 4
• Mycotic aneurysm 4
• Anatomic abnormalities of the splenic vasculature 5

Iatrogenic and Trauma-Related Causes

• Splenic trauma with vascular injury—blunt or penetrating trauma can cause infarction through direct vascular disruption [4, 4
• Angioembolization procedures—intentional or unintentional embolization during therapeutic interventions, with major infarctions occurring in 3.7-28.5% of cases 4
• Post-surgical states including splenectomy complications or bariatric surgery 4
• Cardiopulmonary bypass during cardiac surgery 4

Malignancy-Related Causes

• Solid neoplasms causing hypercoagulability or direct vascular invasion 7
• Hematologic malignancies with associated hyperviscosity or thrombotic tendency [2, 7

Other Causes

• Pancreatic disease with inflammatory extension to splenic vessels 5
• Collagen vascular diseases 5
• Oral contraceptive use causing acquired thrombophilia 4
• Inflammatory bowel disease with associated thrombotic complications 4

Important Clinical Context

Approximately 20% of splenic infarcts are asymptomatic and discovered incidentally 7. In one autopsy series, only 10% of splenic infarctions were suspected clinically despite contributing substantially to morbidity and mortality in 44% of cases 1. Concomitant infarcts in other organ systems occur in 62% of thromboembolic cases 1.

The age-related pattern is critical for diagnostic workup: patients under 40 require hematologic evaluation first, while those over 40 require cardiac evaluation as the primary focus [5, 2.