[Cardiac and extracardiac abscesses in bacterial endocarditis].

Cardiac abscesses are observed in 20 to 30% of cases of infective endocarditis and in at least 60% of prosthetic valve endocarditis. The aortic valve ring is more frequently affected than the mitral valve ring. A cavity contiguous with a cardiac chamber forming a pseudo-aneurysm or a closed purulent collection, the abscess may extend to the neighbouring cardiac structures or to the ascending aorta. This extension may cause conduction defects, abnormal communications between the cardiac chambers, pericardial disease and, exceptionally, myocardial ischaemia, complications which are clinical signs of abscess formation in patients with infective endocarditis. The presence of a cardiac abscess is a poor prognostic factor in infective endocarditis. The diagnosis must be made at an early stage when surgical treatment is optimal. The most valuable investigation is transoesophageal echocardiography with a sensitivity of over 80% and a specificity of about 95%. This investigation has become practically routine in all patients with endocarditis in order to diagnose abscesses at an early stage, especially in cases of aortic or prosthetic valve endocarditis. Information about the site, size and extension of the abscess may be obtained and existing or potential complications may be envisaged with a view to surgery. Other imaging diagnostic techniques, such as angiography, CT scanning and nuclear magnetic resonance imaging have a number of disadvantages and are not more sensitive than transoesophageal echocardiography. Surgical techniques depend on the site and extension of the abscess. They are sutured or closed with dacron or pericardial patches after having been cleaned and filled with formulated resorcin glue. The valvular prosthesis is inserted either in anatomical position or in a sub or supracoronary dacron tube necessitated by the perivalvular extension of the infectious lesions. These complex procedures may require associated coronary reimplantation or revascularisation when the coronary ostia are affected. The highest operative mortality is observed in prosthetic valve endocarditis with abscess and extra-annular prosthetic implants. The risk of secondary valvular dehiscence, often recurrent, is much higher when there is an abscess at operation. Extracardiac abscesses in cases of infective endocarditis are mainly observed in the cerebral and/or splenic territories. They may become the main problem, especially cerebral abscesses, but they rarely require surgery.