New flexible polymeric heart valve prostheses for the mitral and aortic positions.
OBJECTIVE
Current prosthetic heart valves necessitate permanent anticoagulation or have limited durability and impaired hemodynamic performance compared with natural valves. We report in vivo and in vitro results with new polymeric valve prostheses that have a special design for the mitral and aortic positions. The aims are improved durability and elimination of the need for permanent anticoagulation.


METHODS
The mitral and aortic prostheses (Adiam Life Science, Erkelenz, Germany) are made entirely of polycarbonate urethane (PCU). The bileaflet asymmetric mitral valve mimics natural, nonaxial inflow, which creates a left ventricular vortex, saving energy for systolic ejection of blood. The trileaflet aortic prosthesis has diminished pressure loss and reduced stress and strain peaks at the commissures. The valves were subjected to long-term in vitro testing and in vivo testing in a growing calf model (20 weeks; 7 mitral and 7 aortic valves) with comparison with 2 commercial bioprostheses (7 mitral, 2 aortic). Two-dimensional echocardiography was performed after implantation and prior to sacrifice with autopsy and valve examination.


RESULTS
In vitro durability of the PCU valves was proved up to 20 years. In vivo durability and hemodynamics were superior to those of all bioprostheses. Survival of PCU valves versus bioprostheses was 7 versus 2 mitral valves and 5 versus 0 aortic valves, respectively. Two animals with PCU aortic valves died of pannus overgrowth that caused severe left ventricular outflow tract obstruction without changes in the valves. Degeneration and calcification were mild (mitral) and moderate (aortic) in PCU valves but were severe in biological valves. There was no increased thrombogenicity of the PCU valves compared with bioprostheses.


CONCLUSIONS
The new flexible polymeric aortic and mitral valve prostheses were superior to current bioprostheses in animal testing.
Daebritz
Sabine H
SH
Department of Cardiac Surgery, Ludwig-Maximilians-University, Munich, Germany. sabine.daebritz@med.uni-muenchen.de
Fausten
Bernd
B
Hermanns
Benita
B
Franke
Andreas
A
Schroeder
Joerg
J
Groetzner
Jan
J
Autschbach
Ruediger
R
Messmer
Bruno J
BJ
Sachweh
Jörg S
JS
D001021:Aortic Valve / Q000601:surgery*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006350:Heart Valve Prosthesis; D008943:Mitral Valve / Q000601:surgery*; D011108:Polymers
D011108:Polymers