Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Hall C & D
*Purpose: The rate of thawing of cryopreserved human iliac arteries allografts (CHIAA) directly affects the severeness of structural changes that occur during this process. This directly affects the recipient by faster grafts degeneration Elimination of these structural changes is the easiest way to slow down grafts’ degeneration.
*Methods: The experiment was performed on ten CHIAA. The 10% dimethyl sulfide oxide in E 199 was used as the cryoprotectant; all CHIAA were cooled at a controlled rate and stored in liquid nitrogen (-196 ° C). The CHIAA were divided into two groups. Two thawing protocols were tested: 1- placing the CHIAA in a water bath at 37 ° C, 2- the CHIAA were thawed slowly at in a controlled environment at 5° C. All samples underwent analysis under a scanning electron microscope. Testing of the mechanical properties of the CHIAA was evaluated on a custom-built single axis strain testing machine. Longitudinal and circumferential samples were prepared from each tested CHIAA. The samples stress-strain data were measured until rupture.
*Results: Histological analysis revealed that all five CHIAA thawed during thawing protocol 1 showed significantly more severe damage to the subendothelial structures when compared to the samples thawed in protocol 2. Mechanical properties: Thawing protocol 1- longitudinal ultimate tensile strain (UTS) 2,42 ± 0,34 MPa at relative strain 1,32 ± 0,09, circumferential UTS 1,98 ± 0,26 MPa at relative strain 1,29 ± 0,07. Thawing protocol 2 – longitudinal UTS 2,53 ± 0,47 MPa at relative strain 1,27 ± 0,12, circumferential UTS 1,94 ± 0,27 MPa at relative strain 1,33 ± 0,09. Comparing UTS showed no statistical difference between thawing methods.
*Conclusions: Despite the significant differences in structural changes of presented thawing protocols, the UTS showed no statistical difference between thawing methods. Thus, the rate of CHIAA thawing does not affect CHIAA mechanical properties. However, this does not mean that the structural changes occurring during thawing do not affect the clinical performance of the CHIAA in other aspects.
Supported by Ministry of Health of the Czech Republic, grant nr. 18-02-00422
To cite this abstract in AMA style:Novotny R, Chlupac J, Matejka R, Marada T, Mericka P, Sterba L, Janousek L, Fronek J. Cryopreserved Human Iliac Arteries Allografts: Different Thawing Rates Affect on Their Structural Changes and Mechanical Properties [abstract]. Am J Transplant. 2019; 19 (suppl 3). https://atcmeetingabstracts.com/abstract/cryopreserved-human-iliac-arteries-allografts-different-thawing-rates-affect-on-their-structural-changes-and-mechanical-properties/. Accessed March 6, 2021.
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