The mechanical properties of fresh and cryopreserved arterial homografts.

Abstract

To assess the effect of cryopreservation on the elasticity and compliance of arterial allografts. Iliofemoral segments of arteries and veins harvested from multiorgan donors were divided into two groups: fresh-control, tested for 24 hours after harvesting, and cryopreserved in liquid nitrogen after pretreatment with 20% dimethylsulphoxide and stored for an average time of 22 days. Vessel wall elastic properties were evaluated from the stress-strain relationship in a specially designed test cell fixed to the Instron Universal Testing Machine. The elastic modulus of the artery control group (1.54+/-0.33 MPa, n=20) was not significantly different from the cryopreserved group (1.69+/-0.61 MPa, n=15). Similarly, values for unfrozen veins (3.11+/-0.65 MPa, n=47) were not significantly different from those of frozen samples (2.71+/-0.85 MPa, n=38). Control compliance (6. 86+/-1.79x10(-5)%/Pa, for arteries; 3.84+/-0.81x10(-5)%/Pa, for veins) was similar to that of the cryopreserved group (6.66+/-1. 80x10(-5)%/Pa, for arteries; 4.16+/-1.21x10(-5)%/Pa, for veins). Cryopreservation maintains the important elastic properties of arterial and venous allografts during average storage time of 22 days.