Bacterial Endocarditis Following Aortic Valve Replacement

The clinical and pathologic findings in three patients with bacterial infection at the sites of prosthetic aortic valves are described. Each presented typical clinical features of acute bacterial endocarditis followed by the sudden development of severe and ultimately fatal aortic regurgitation. Pathologically the infectious process was characterized by extensive necrosis of the aortic annulus, disruption of the aortic wall, and the formation of abscesses in the periaortic tissues. In two patients the prosthetic valve was partially detached from the annulus, whereas in the other it was totally dislodged and impacted in the aortic arch shortly before death. In all, secondary operative intervention would have been fruitless because of the extent of the infection and the character of the tissue at the aortic root. In one patient fatal staphylococcal endocarditis followed dental extractions despite penicillin prophylaxis. A more comprehensive antibiotic regimen for patients with prosthetic cardiac valves is suggested.