Infective Endocarditis, Splenic Embolism and Splenectomy: Radiologic and Histopathologic Aspects

Splenic embolism (SE) is a frequent complication of infective endocarditis (IE). Splenectomy is performed in specific situations, such as in the presence of multiple or large abscesses or infarcts. The aim of this study is to describe radiologic and histopathologic (HP) characteristics of SE and to compare patients with SE who underwent splenectomy with those who did not. Adult patients with definite IE were prospectively enrolled and analyzed post hoc. Patients systematically underwent contrast-enhanced computed tomography (CT). Patients with SE who underwent splenectomy were designated group 1 (G1), and those who did not, group 2 (G2). Statistical analysis was performed using Jamovi 2.6.13. From 2006–2024, 176/532 (33.1%) adults with IE had SE; 57 (32.4%) underwent splenectomy. Splenectomy was performed before cardiac surgery (CS) in 26/43 (60.5%) and after CS in 17 (39.5%). Median age was 45 years in G1 and 51 years in G2 (p NS). Duration of antimicrobial therapy was 13 7–19.25 days and 19 11–40 days for those splenectomized before and after CS, respectively (p NS). There were no differences in the proportion of healthcare-associated IE (24.6% vs 22.7%), diabetes mellitus (7% vs. 14.3%) or chronic kidney disease (26.3% vs. 27.7%). Splenic abscess on CT was diagnosed in 7/50 (14%) in G1 vs. 1/115 (0.9%) in G2 (p<0.001), and large splenic infarcts in 7/50 (14%) in G1 vs. 4/112 (3.6%) in G2 (p = 0.036). Sequential CT was performed in 33.5% of cases (median 24.7 days) and showed enlargement or new splenic lesions in 9/14 (63%) in G1 vs. 9/45 (20%) in G2 (p = 0.002). There was no statistical difference in the frequency of staphylococci (12.3% vs. 9.2%), enterococci (14.3% vs. 8.8%), or oral streptococci (26.3% vs. 17.6%). In-hospital mortality was similar (26.3% vs. 26.1%). The most frequent pathologic findings were presence of microorganisms and/or polymorphonuclear leukocytes (PMN) in 32/42 (76%), hemorrhage in 10 (24%), splenitis in 8 (19%) and splenic capsule rupture in 6 (14%). Among 24 patients with PMN on HP, 21 (87.5%) had no abscess reported on previous CT. There was a high frequency of complicated SE and subsequent splenectomy. Most removed spleens were severely compromised. The majority of patients with PMN on HP did not have an abscess described on prior CT scans.