Non-invasive biomechanical evaluation of implanted human cryopreserved arterial homografts: comparison with pre-implanted cryografts and arteries from human donors and recipients.
Native vessels-grafts biomechanical mismatch (BM) is related to graft failure. The BM could be reduced using human cryopreserved/defrosted arteries (cryografts), but post-thaw cryografts' recovery could be associated with an impaired biomechanical behavior. In vitro, we demonstrated that our cryopreservation methods do not affect arteries' biomechanics, but only post-implant studies would allow determining the cryografts' biomechanical performance.


OBJECTIVE
To characterize the biomechanical properties of implanted cryografts, and to compare them with cryografts pre-implant, recipients' native arteries, and arteries from subjects with characteristics similar to those of the recipients and multiorgan donors (MOD) whose arteries were cryopreserved.


METHODS
Native femoral arteries anastomosed to cryografts, implanted cryografts, and arteries from subjects, recipient-like and MOD-like, were studied. In vitro (pre-implant cryografts) and in vivo non-invasive studies were performed. Arterial pressure, diameter, and wall thickness were obtained to quantify local and regional biomechanical parameters, and to evaluate the arterial remodeling.


CONCLUSIONS
Implanted cryografts were remodeled, with an increased wall thickness, wall-to-lumen ratio, and wall cross-sectional area. The proximal-distal gradual transition in stiffness remained unchanged. Implanted cryografts were stiffer than MOD-like arteries, but more compliant than recipients' arteries. The cryografts-native arteries biomechanical differences were lesser than those described for venous grafts or expanded polytetrafluoroethylene.
Bia
Daniel
D
Physiology Department, School of Medicine, Republic University, General Flores 2125, 11800, Montevideo, Uruguay. dbia@fmed.edu.uy
Zócalo
Yanina
Y
Armentano
Ricardo
R
Laza
Sebastián
S
Pérez
Héctor
H
Craiem
Damián
D
Saldías
María
M
Alvarez
Inés
I
D000368:Aged; D001158:Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000637:transplantation*; D001696:Biomechanical Phenomena; D001807:Blood Vessel Prosthesis; D015925:Cryopreservation / Q000379:methods*; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical; D014019:Tissue Donors