Discussion
Perivalvular abscess is a more common complication of prosthetic than native valve endocarditis. It is not necessarily associated with more virulent microorganisms. If the clinical response to optimum antimicrobial therapy is poor or other signs of uncontrolled sepsis are observed, the diagnosis of abscess formation should be suspected [1]. In a report, aortic-root abscess occurred in 52% of prosthetic valve endocarditis compared with 15% of cases of native valve endocarditis [2]. In an autopsy series of 95 patients with endocarditis, 27 had valve ring abscesses; five clinical clues suggested its presence. The clues were as follows: (a) endocarditis involving the aortic valve; (b) the presence of valvular regurgitation of recent onset; (c) evidence of pericarditis; (d) evidence of high-degree atrioventricular block; and (e) a short duration of symptoms caused by endocarditis [3].