Constitutive models describing the arterial mechanical behavior are important in the development of catheterization products, to be used in arteries with a specific radius. To prove the possible existence of a constitutive model that, provided with a generic set of material and geometric parameters, is able to predict the radius-specific mechanical behavior of a coronary artery, the passive pressure-inner radius (P-r ( i )) and pressure-axial force change (P-?F ( z )) relations of seven porcine left anterior descending coronary arteries were measured in an in-vitro set-up and fitted with the model of Driessen et?al. in J Biomech Eng 127(3):494-503 (2005), Biomech Model Mechanobiol 7(2):93-103 (2008). Additionally, the collagen volume fracti...