European Journal of Cardio-Thoracic Surgery, Vol 7, 591-596, Copyright © 1993 by European Association for Cardio-thoracic Surgery
Spontaneous host endothelial growth on bioprosthetic valves and its relation to calcification
K Liao, G Gong, D Hoffman, E Seifter, SM Factor, F Macaluso and RW Frater
Department of Cardiothoracic Surgery, Albert Einstein College of Medicine, Bronx, New York 10461.
We studied host endothelial growth and calcification of bovine pericardial
valve prostheses treated with: (A) 0.625% glutaraldehyde + 4% formaldehyde,
(B) 99.5% glycerol or (C) 99.5% glycerol + 4% formaldehyde. Twenty-three
stentless chordally supported bileaflet pericardial mitral valves with
treatments A (n = 6), B (n = 6) or C (n = 11) were implanted in juvenile
sheep for 125-273 days. After sacrifice, the anterior cusp from the annulus
to papillary muscle of each valve was examined by scanning electron
microscopy for the presence of endothelial cells, and the intrinsic
calcification of each valve was determined by measuring calcium
(micrograms/mg dry weight) from another 1 cm2 piece of grossly normal cusp.
Sixty pieces of 1 cm2 pericardium with treatment A, B or C (n = 20 in each
group) were implanted in 30 rats for 70 days. Calcium analysis and
histology study of the implants were performed. In sheep, within a similar
range of implantation periods, the endothelial growth rate of the valves
was the highest in group B, 100% (6/6); group C was 45.5% (5/11) and A
16.7% (1/6). There were no significant differences in calcium among groups
A, B and C. In rat implants, the calcium of group B was much lower than
that of A or C (B = 6.92 +/- 4.46 vs A = 144.52 +/- 27.66 or C = 240.54 +/-
13.47, P < 0.05) although its histology showed more severe degeneration
and inflammatory changes. Pericardial mitral valves treated with glycerol
show satisfactory biocompatibility with regard to host endothelial growth
and prevention of calcification; however, these tissues show evidence of
rapid degeneration.(ABSTRACT TRUNCATED AT 250 WORDS)
