Abstract: Methods for forming a support frame for flexible leaflet heart valves from a starting blank include converting a two-dimensional starting blank into the three-dimensional support frame. The material may be superelastic, such as NITINOL, and the method may include bending the 2-D blank into the 3-D form and shape setting it. A merely elastic material such as ELGILOY may be used and plastically deformed in stages, possibly accompanied by annealing, to obtain the 3-D shape. Alternatively, a tubular blank could be formed to define a non-tubular shape, typically conical. A method for calculating the precise 2-D blank shape is also disclosed. A mandrel assembly includes a mandrel and ring elements for pressing the blank against the external surface of the mandrel prior to shape setting.

Abstract: A flexible prosthetic tissue-type heart valve having commissures that are substantially decoupled from a cusp support structure. The valve includes three leaflets having arcuate cusp edges and opposed concave shaped free edges, with outwardly-directed attachment tabs therebetween. A cusp support structure in either one or more pieces attaches to the leaflet cusp edges. Three commissures are each formed partly with an axially-extending insert member to which two adjacent leaflet tabs attach. An inverted V-shaped clip maintains close contact between the adjacent leaflet tabs and provides a stress-relieving clamping action in conjunction with the insert member. The insert member attaches about its lower end to base sections of the cusp support structure, or to an intermediate sewing ring, so that the commissures may pivot about the cusp support structure.

Abstract: Bioprosthetic tissues are treated by immersing or otherwise contacting fixed, unfixed or partially fixed tissue with a glutaraldehyde solution that has previously been heat-treated or pH adjusted prior to its contact with the tissue. The prior heat treating or pH adjustment of the glutaraldehyde solution causes its free aldehyde concentration to decrease by about 25% or more, preferably by as much as 50%, and allows a “stabilized” glutaraldehyde solution to be obtained at the desired concentration and pH for an optimal fixation of the tissue at high or low temperature. This treatment results in a decrease in the tissue's propensity to calcify after being implanted within the body of a human or animal patient.