Kj. Lockie et al., BIOMECHANICS OF GLUTARALDEHYDE-TREATED PORCINE AORTIC ROOTS AND VALVES - AN INVESTIGATION OF THE EFFECT OF PREDILATION OF THE ELASTIC AORTIC ROOT, Journal of thoracic and cardiovascular surgery, 108(6), 1994, pp. 1037-1042
The biomechanics and function of fresh porcine aortic roots and valves
have been compared, with those of glutaraldehyde-treated roots prepar
ed in a conventional manner without dilation of the elastic aortic roo
t and with glutaraldehyde-treated roots prepared with permanent predil
ation during fixation. The glutaraldehyde-treated aortic walls were si
gnificantly less extensible than fresh walls, with a mean dilation of
only 6% compared with 45% for the fresh root at 120 mm Hg pressure, Pe
rmanent predilation of the aortic root during fixation allowed the tot
al dilation of the fixed root to be increased to 19% at 120 mm Hg pres
sure. The effective orifice area of the fresh root and valve was signi
ficantly greater than those of the fixed roots and valves, with perman
ent predilation fixation producing a significantly greater orifice are
a than conventional fixation. The open-leaflet bending deformations we
re found to be lower in the valves fixed after permanent predilation t
han in the standard fixed valves. The glutaraldehyde-treated porcine r
oot and valve does not reproduce the biomechanics and function of the
fresh root, because of the reduced extensibility of the fixed aortic n
ail. Permanent predilation during fixation helps to partially overcome
the shortcomings of the fixed root, producing better function than a
standard fixed valve.