The glutaraldehyde-treated heterograft valve: some engineering observations.

Two commercially prepared, glutaraldehyde-treated porcine heterograft valves mounted on flexible stents have been tested in a pulsatile-flow water tunnel. Measurements of the radial deflections of the stent posts have been made for various applied pressures across the valve. A previous claim of 90 percent reduction in leaflet stress as a result of stent flexibility is of doubtful validity because the measurement technique used was inappropriate for the magnitude of strain involved. Photographs of the valve at various steady forward flow rates show that the leaflets do not open as readily as the antibiotic-treated homograft valve.