Mn. Girardot et al., ROLE OF GLUTARALDEHYDE IN CALCIFICATION OF PORCINE HEART-VALVES - COMPARING CUSP AND WALL, Journal of biomedical materials research, 29(7), 1995, pp. 793-801
Experiments were performed to better understand the relationship betwe
en glutaraldehyde and calcification of bioprosthetic heart valves, usi
ng both the cusps and the wall of porcine aortic roots. The results of
the first experiment, for which H-3-labeled glutaraldehyde solutions
were used, indicated that binding of glutaraldehyde in cusps and wall
is concentration-dependent, that the wall contains significantly less
glutaraldehyde than the cusp, and that glutaraldehyde, which penetrate
s in the wall at similar rates from the intima and the adventitia, is
homogeneously distributed throughout the wall after 7 days of fixation
, except for the intima side, where it is significantly lower. The res
ults of the second experiment, for which cusps and 1-cm(2) pieces of w
all from glutaraldehyde-fixed porcine aortic roots were implanted subd
ermally in young rats, indicated that for both types of tissue, calcif
ication appears to first initiate predominantly in the cell nuclei bef
ore extending to the other structures. After 8 weeks of implantation,
whereas the cusps were completely calcified, calcification of the wall
was limited to two longitudinal bands 150-300 mu m thick, located bel
ow the adventitia and intima surfaces. The results of the third experi
ment indicated that cusp calcification, which decreased significantly
after a 12-month storage period, was reset to high levels by reexposin
g the valves to glutaraldehyde at the end of the 12-month storage peri
od. Wall calcification remained constant under all tested conditions.
The results suggest that the mechanism(s) of calcification in the wall
and the cusp may be different, and that calcification may be related
to a particular molecular configuration resulting from exposure to glu
taraldehyde. (C) 1995 John Wiley and Sons Inc.