[A case of primary tissue failure in aortic bioprosthesis due to pannus formation]

A 22-year-old man, who had received aortic valve replacement with a 21 mm of Carpentier-Edward S.A.V Bioprosthesis for aortic regurgitation at 19 years of age, was readmitted to our hospital because of a new systolic murmur and his chest roentgenogram showed remarkable cardiomegaly. Cardiac catheterization showed a 55 mmHg pressure gradient across the bioprosthesis. Under the diagnosis of primary tissue failure, reoperation was undergone. At reoperation, the sewing ring and leaflets of the prosthesis were covered with pannus, which adhered to leaflets, and the thickness of these leaflets was seen. It was thought that these changes caused aortic stenosis. Primary tissue failure due to pannus formation has been reported a little, but if bioprosthesis is implanted in the supra-annular position, pannus formation may occur because cusps of bioprosthesis are attached to the host's annulus.