A fascial frustum valve fr aortic valve replacement.

After consideration of detailed measurements of normal aortic valves the shape of the fascial component adopted was a frustum (horizontal section of a cone). This affords sufficient tissue for natural cusp configuration without shaping, overcoming the difficulty of cusp disproportion and allowing natural variation in individual cusp size. In the open position the valve's cross-sectional area progressively increases from its base at the aortic root to its distal attachment. Each aortic root size requires a different frustum which has to be calculated. Considering Fig. 1, r is the radius of the respective aortic root and R is the maximum radius of the aorta below the sinus ridges. The value of R is a mean of measurements directly taken of a series of hearts. This value was found to have significant correlation in different hearts of the same aortic root size, except in cases of Marfan's disease and syphilitic aortitis.