Correlation between structural changes and acute thrombogenicity in transcatheter pericardium valves after crimping and balloon deployment.
INTRODUCTION
Transcathether heart valve replacement has gained considerable acceptance during the last decades. It is now part of the armamentarium for aortic valve replacement. The procedure proved to be highly efficient. However the issues of the blood compatibility and tissue durability were not raised and the adverse events were probably under-reported, according to observations of thrombosis after deployment.


MATERIAL AND METHOD
Bovine pericardium leaflets were sewn inside a 26mm diameter stainless steel stent to manufacture these valves (one control and two experimental). The correlation between the trauma and the acute thombogenicity of bovine pericardium leaflets, after crimping and ballooning, was investigated via an in vitro blood flow with labeled platelets. These leaflets were processed for histology: scanning electron microscopy, light microscopy, and transmission electron microscopy.


RESULTS
The control specimens showed a regular pericardium structure with some blood cells deposited on the collagen fibrous surface (inflow) and scarce blood cells deposited on the serous surface (outflow). After crimping and ballooning, the structure of the pericardium was severely injured, eventually with delaminations and ruptures. The blood cell uptake was considerably increased compared to the control.


CONCLUSION
It would therefore be appropriate to pay more attention to the design of the valves. Specifically, the incorporation of a buffer tissue or fabric between the pericardium and the metallic stent is suggested. The issue of ballooning deserves detailed and in depth investigation regarding the lifetime of the device.
['Bourget|J-M|JM|', 'Zegdi|R|R|', 'Lin|J|J|', 'Wawryko|P|P|', 'Merhi|Y|Y|', 'Convelbo|C|C|', 'Mao|J|J|', 'Fu|Y|Y|', 'Xu|T|T|', 'Merkel|N O|NO|', 'Wang|L|L|', 'Germain|L|L|', 'Zhang|Z|Z|', 'Guidoin|R|R|']
D000818:Animals D001021:Aortic Valve D063126:Balloon Valvuloplasty D001705:Bioprosthesis D001775:Blood Circulation D002417:Cattle D064368:Healthy Volunteers D006350:Heart Valve Prosthesis D006801:Humans D008855:Microscopy, Electron, Scanning D046529:Microscopy, Electron, Transmission D010496:Pericardium D011474:Prosthesis Design D015607:Stents D013499:Surface Properties D013927:Thrombosis D065467:Transcatheter Aortic Valve Replacement
Crimping Ballooning Thrombosis Delamination Délamination Expansion Sertissage TAVI Thrombose