[Splenic involvement in infectious endocarditis. Association for the Study and Prevention of Infectious Endocarditis]

Splenic involvement in the course of endocarditis consists in either splenic infarct or abscess. Pathophysiological examinations suggest the existence of a continuum between the two types of lesion. Signs and symptoms are usually poor or aspecific. Current incidence and diagnostic methods are rarely reported in recent medical literature.

We report a retrospective study conducted from a questionnaire that was circulated to nine French medical units. Two hundred and twenty five patients with infectious endocarditis according to Duke university criteria were included in the study. The existence of splenic lesions was investigated in 153 patients (68%). Splenic involvement was documented in 35 patients. Diagnostic methods were: abdominal echography (n = 77), abdominal CT scan (n = 40), and both techniques (n = 36). The incidence of splenic lesions was 9%, 35% and 36%, respectively. Among patients investigated using both diagnostic techniques, splenic abnormalities were detected by CT scan in 13 cases and by echography in six cases. Splenic abscess was suspected in nine patients by combining suggestive clinical course and radiological abnormalities, but was definitively evidenced in only four patients (surgery, n = 2, post-mortem examination, n = 2) presenting with large lesions (> or = 8 cm) associated with aortic endocarditis. All other 26 cases were categorized as splenic infarcts; however, diagnosis was confirmed in only two cases (surgery n = 1, autopsy n = 1).

These data suggest that: 1) the incidence of splenic involvement during endocarditis is approximately 35%, 2) CT scan is probably superior to echography for spleen screening, and 3) incidence of abscess requiring specific surgery is very low, inferior to 2%.