[Aortic valve replacement by bioprosthesis with enlargement of the aortic ring].

Small diameter aortic valve bioprostheses are associated with resting ventriculo-aortic pressure gradients of 10 to 35 mmHg. In order to avoid this factor favouring degradation of left ventricular function and early deterioration of the bioprosthesis, we enlarged the aortic ring when the diameter was less than 23 mm in patients considered unsuitable for long-term anticoagulation. The surgical technique involved incising the annulus from the postero-lateral commissure to the anterior mitral leaflet and implanting a Dacron patch lined with pericardium. Nine patients aged from 10 to 70 years (average 22 years) underwent aortic valve replacement with a Carpentier-Edwards bioprosthesis associated with enlargement of the aortic ring, between June 1979 and December 1981. The mean follow-up period is now 18 months (range 9 to 39 months). One patient has been lost to follow-up. Before surgery, 6 patients were in Stage III and 3 patients in Stage IV of the NYHA classification. There were 4 patients with pure aortic regurgitation with valve prolapse, 1 patient with aortic regurgitation due to endocarditis, and 4 patients with mixed aortic valve disease. The underlying disease was rheumatic in 6 cases, congenital in 2 cases and infective endocarditis in 1 case. The mean diameter of the aortic ring before enlargement was 19 mm. After the procedure, it increased to 23,8 mm, so enabling the implantation of no 23 and no 25 bioprostheses. Three patients had associated mitral regurgitation, 3 patients had mixed mitral valve disease, 1 patient had a membranous VSD with infundibular stenosis, and 1 patient had subvalvular aortic stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)