The use of mechanical prostheses in native aortic valve endocarditis

The optimal aortic valve substitute in cases of active native valve endocarditis (NVE) remains controversial. This report summarizes our experience with the surgical treatment of active aortic NVE using only mechanical prostheses.

Between January 1988 and January 1996, 20 patients underwent aortic valve replacement for active NVE. There were 17 men and three women. Mean age was 46.5 years (range eight to 63 years). Thirteen patients were in NYHA class IV and seven in class V. Streptococci were isolated in eight cases, while no causative micro-organism could be identified in seven patients. All operations were performed on urgent (n = 13) or emergency (n = 7) bases. A mechanical valve was implanted in all cases and radical resection of the infected tissues performed using different techniques. All patients were followed up at our institution. Two-dimensional color Doppler studies were performed one month after surgery and at six-month intervals after the first year. Transesophageal echocardiography (TEE) was performed at discharge, six months after surgery and yearly thereafter.

No patient died in hospital. Mean follow up was 30.5 months, during which time three patients died, though none from endocarditis-related causes. Endocarditis recurred only one (5%). TEE demonstrated a normally functioning aortic prosthesis in 15 cases and trivial paravalvular leakage in two.

Mechanical prostheses represent a safe aortic valve substitute in cases of acute native valve endocarditis. When radical resection of all the infected areas is performed, the incidence of endocarditis recurrence is acceptable. The concept that homografts are the valve substitute of choice in endocarditis cases cannot be supported by this study.