ADAPT-treated porcine valve tissue (cusp and wall) versus Medtronic Freestyle and Prima Plus: crosslink stability and calcification behavior in the subcutaneous rat model.
OBJECTIVE
The study aim was to compare the crosslink stability and calcification behavior of porcine tissue (cusp and wall), treated with a new antimineralization process (ADAPT) with that of commercially prepared Freestyle and Prima Plus bioprosthetic tissues.


METHODS
Porcine aortic roots were divided into two groups: (i) tissue zero pressure-fixed with 0.625% glutaraldehyde (GA) for seven days and stored in 0.25% GA (as control); and (ii) tissue exposed to the ADAPT process for four days and stored in 0.25% buffered GA. These groups were compared with Freestyle and Prima Plus tissues (cusp and wall). Crosslink stability was assessed by shrinkage temperature and resistance to pronase degradation. Calcification behavior was assessed histologically (Von Kossa staining) and by atomic absorption spectrophotometry of explanted tissue after eight weeks. in a subcutaneous rat model.


RESULTS
Crosslink stability and calcification potential of ADAPT-treated porcine valve cusps were comparable to those of Freestyle and Prima Plus cusps (p = NS). ADAPT-treated porcine wall tissue showed improved crosslink stability (p <0.05) and significantly (p <0.001) reduced calcification (-95.95%) compared to control (-0.00%), Freestyle (-47.87%) and Prima Plus (-51.95%) tissues.


CONCLUSIONS
The ADAPT process is effective in reducing calcification in both porcine cusp and wall tissues in a subcutaneous rat model, and further suggest that enhanced crosslinking plays an important role in minimizing aortic wall calcification.
Fremantle Heart Institute and University of Western Australia, Department of Cardiothoracic, Fremantle Hospital, Western Australia. Leon.Neethling@health.wa.gov.au
William M L
WM
Neethling
Ross
R
Glancy
Andrew J
AJ
Hodge
D000818:Animals; D001021:Aortic Valve / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D001705:Bioprosthesis; D002114:Calcinosis / Q000188:drug therapy* / Q000378:metabolism / Q000517:prevention & control; D002118:Calcium / Q000378:metabolism; D002482:Cellulose / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004195:Disease Models, Animal; D004338:Drug Combinations; D004389:Durable Medical Equipment; D004492:Edetic Acid / Q000627:therapeutic use*; D005404:Fixatives / Q000494:pharmacology; D005976:Glutaral / Q000494:pharmacology; D006350:Heart Valve Prosthesis; D008297:Male; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index; D013552:Swine; D013849:Thimerosal / Q000627:therapeutic use*
D003432:Cross-Linking Reagents; D004338:Drug Combinations; D005404:Fixatives; D013849:Thimerosal; D002482:Cellulose; D004492:Edetic Acid; D002118:Calcium; D005976:Glutaral