Kangaroo versus porcine aortic valve tissue--valve geometry morphology, tensile strength and calcification potential.
OBJECTIVE
Valve related factors and patient related factors are responsible for calcification of valvular bioprostheses. Recent studies showed different donor and recipient species have different influences on the total calcification rate of bioprostheses. This study was performed to evaluate and compare Kangaroo aortic valve leaflets with porcine aortic valve leaflets. Experimental design. Prospective study. Setting. Cardio-thoracic experimental research of a university department.


METHODS
Glutaraldehyde-fixed Kangaroo and porcine valve leaflets were evaluated in vitro according to valve geometry (internal diameter and leaflet thickness), morphology (light and electron microscopy) and tensile strength. In vivo evaluation consisted of implantation in a rat model for 8 weeks, Von Kossa stain for calcium and atomic absorption spectrophotometry for total extractable calcium content.


RESULTS
Kangaroo valves indicated a smaller internal valve diameter as well as a thinner valve leaflet (p<0.01, ANOVA) at corresponding body weight, less proteoglycan spicules in the fibrosa, increased elasticity (p<0.05) and low calcification potential (p<0.01, confidence interval 95%).


CONCLUSIONS
Kangaroo aortic valve leaflets have different valvular qualities compared to porcine valve tissue. Kangaroo valve leaflets are significantly superior to porcine valve leaflets as far as calcification is concerned. These results are encouraging and suggest further in vivo evaluation in a larger animal model before clinical application can be considered.
Neethling
W M
WM
Department of Cardio-thoracic Surgery, University of the Free State, Bloemfontein, South Africa.
Papadimitriou
J M
JM
Swarts
E
E
Hodge
A J
AJ
D000818:Animals; D001021:Aortic Valve / Q000737:chemistry / Q000503:physiopathology / Q000637:transplantation / Q000648:ultrastructure; D001705:Bioprosthesis; D002114:Calcinosis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D002118:Calcium / Q000378:metabolism; D006350:Heart Valve Prosthesis; D007614:Macropodidae; D008297:Male; D011446:Prospective Studies; D011475:Prosthesis Failure; D051381:Rats; D017208:Rats, Wistar; D012867:Skin; D013045:Species Specificity; D013054:Spectrophotometry, Atomic; D013552:Swine; D013718:Tensile Strength / Q000502:physiology; D016378:Tissue Transplantation / Q000379:methods
D002118:Calcium