Abstract:

BACKGROUND: The human homograft valve has been widely used in the operation of the valve replacement and congenital heart disease. However, reports concerning pulmonary valve biomechanical suitability as a long-term substitute for aortic valve are limited.
OBJECTIVE: To compare the biomechanical properties between human aortic and pulmonary valves conserved with ultra low temperature in liquid nitrogen.
METHODS: A contrast observation trial was conducted in the laboratory of Congenital Heart Disease of Fuwai Hospital from March to July in 2004. Six samples of heart aorta valves and pulmonary valves were collected from the cadaveric heart within 6 hours, and the experimental procedure was disposed according to ethical criteria. The biomechanical properties of the circumferential direction of the valve were investigated using uniaxial tensile tests. The thickness of the valve was measured by HD-10 thickness instruments.
RESULTS AND CONCLUSIONS: Compared to human aortic valves, the thickness of the human pulmonary valves was thinner significantly, but the stress-strain, tensile strength and the maximum tangent modulus E (the slope of linear segment) in the curve had no significant difference (P > 0.05). Biomechanical differences between the aortic and pulmonary valve are minimal, in respect, pulmonary valve can be considered biomechanically suitable for aortic valve replacement.