The mechanical properties of fresh and cryopreserved arterial homografts

Objectives: to assess the effect of cryopreservation on the elasticity and compliance of arterial allografts. Materials and methods: 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% dimethlysulphoxide 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. Results: 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 +/- 1.79 x 10(-5) %/Pa, for arteries; 3.84 +/- 0.81 x 10(-5) %/Pa, for veins) was similar to that of the cryopreserved group (6.66 +/- 1.80 x 10(-5) %/Pa, for arteries; 4.16 +/- 1.21 x 10-5 %/Pa, for veins). Conclusions: cryopreservation maintains the important elastic properties of arterial and venous allografts during average storage time of 22 days.