INTRODUCTION: The rate of thawing of cryopreserved human iliac arteries allografts (CHIAA) directly affects the severeness of structural changes that occur during this process. METHOD: The experiment was performed on ten CHIAA. The 10% dimethylsulphoxide in 6% hydroxyethyl starch solution was used as the cryoprotectant; all CHIAA were cooled at a controlled rate and stored in the vapor phase of liquid nitrogen (-194°C). Two thawing protocols were tested: (1) placing the CHIAA in a water bath at 37°C, and (2) the CHIAA were thawed 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. RESULTS: Ultrastructural analysis revealed that all five CHIAA thawed during the thawing protocol 1 which showed significantly more damage to the subendothelial structures when compared to the samples thawed in protocol 2. Mechanical properties: Thawing protocol 1-longitudinal UTS 2, 53 ± 0, 47 MPa at relative strain 1, 27 ± 0, 12 and circumferential UTS 1, 94 ± 0, 27 MPa at relative strain 1, 33 ± 0, 09. Thawing protocol 2-longitudinal ultimate tensile strain (UTS) 2, 42 ± 0, 34 MPa at relative strain 1, 32 ± 0, 09 and circumferential UTS 1, 98 ± 0, 26 MPa at relative strain 1, 29 ± 0, 07. Comparing UTS showed no statistical difference between thawing methods. CONCLUSION: Despite the significant differences in structural changes of presented thawing protocols, the ultimate tensile strain showed no statistical difference between thawing methods.

2nd Department of Cardiovascular Surgery General University Hospital Prague Czech Republic

Department of Anatomy 2nd Faculty of Medicine Charles University Prague Czech Republic

Department of Biomedical Engineering Faculty of Biomedical Engineering Czech Technical University Prague Czech Republic

Department of Cardiovascular Surgery Institute for Clinical and Experimental Medicine Prague Czech Republic

Tissue Bank Faculty Hospital Hradec Kralove Hradec Kralove Czech Republic

Transplant Surgery Department Institute for Clinical and Experimental Medicine Prague Czech Republic

Zobrazit více v PubMed

Ratliff C. R., Strider D., Flohr T., et al. Vascular graft infection: incidence and potential risk factors. Journal of Wound, Ostomy, and Continence Nursing. 2017;44(6):524–527. doi: 10.1097/WON.0000000000000376. PubMed DOI

Měřička P., Špaček M., Janoušek L., et al. Cryopreservation of vascular grafts for clinical use: retrospective analysis of pre-freezing factors with potential impact on the quality and safety of vascular transplantations. Cryobiology. 2015;71(3):546–547. doi: 10.1016/j.cryobiol.2015.10.041. DOI

Wang S. K., Gutwein A. R., Drucker N. A., et al. Cryopreserved homografts in infected infrainguinal fields are associated with frequent reinterventions and poor amputation-free survival. Annals of Vascular Surgery. 2018;49:24–29. doi: 10.1016/j.avsg.2017.10.032. PubMed DOI

L'Italien G. J., Maloney R. D., Abbott W. M. The preservation of the mechanical properties of venous allografts by freezing. Journal of Surgical Research. 1979;27(4):239–243. doi: 10.1016/0022-4804(79)90136-7. PubMed DOI

Lopez M. J. Creative technology advances tissue preservation. Annals of Translational Medicine. 2017;5(23):p. 463. doi: 10.21037/atm.2017.09.08. PubMed DOI PMC

van Kats J. P., van Tricht C., van Dijk A., et al. Microbiological examination of donated human cardiac tissue in heart valve banking. European Journal of Cardio-Thoracic Surgery. 2010;37(1):163–169. doi: 10.1016/j.ejcts.2009.07.011. PubMed DOI

Špaček M., Měřička P., Janoušek L., et al. Current vascular allograft procurement, cryopreservation and transplantation techniques in the Czech Republic. Advances in Clinical and Experimental Medicine. 2019;28(4):529–534. doi: 10.17219/acem/90037. PubMed DOI

Krs O., Burkert J., Slízová D., Kobylka P., Spatenka J. Allograft semilunar cardiac valves processing and cryopreservation - morphology in scanning electron microscope. Cell and Tissue Banking. 2006;7(3):167–173. doi: 10.1007/s10561-004-1889-y. PubMed DOI

Bia D., Pessana F., Armentano R., et al. Cryopreservation procedure does not modify human carotid homografts mechanical properties: an isobaric and dynamic analysis. Cell and Tissue Banking. 2006;7(3):183–194. doi: 10.1007/s10561-005-0655-0. PubMed DOI

Buján J., Pascual G., López R., et al. Gradual thawing improves the preservation of cryopreserved arteries. Cryobiology. 2001;42(4):256–265. doi: 10.1006/cryo.2001.2329. PubMed DOI

Gallo M., Bonetti A., Poser H., et al. Decellularized aortic conduits: could their cryopreservation affect post-implantation outcomes? A morpho-functional study on porcine homografts. Heart and Vessels. 2016;31(11):1862–1873. doi: 10.1007/s00380-016-0839-5. PubMed DOI

Novotny R., Slizova D., Hlubocky J., et al. Cryopreserved human aortic root allografts arterial wall: structural changes occurring during thawing. PLoS One. 2017;12(4, article e0175007) doi: 10.1371/journal.pone.0175007. PubMed DOI PMC

Manaa J., Sraieb T., Khayat O., Ben Romdhane N., Hamida J., Amor A. The effect of cryopreservation on the structural and functional properties of human vascular allografts. La Tunisie Médicale. 2003;81(Supplement 8):645–651. PubMed

Esther Rendal Vázquez M., Rodríguez Cabarcos M., Fernández Mallo R. O., et al. Functional assessment of human femoral arteries after cryopreservation. Cryobiology. 2004;49(1):83–89. doi: 10.1016/j.cryobiol.2004.04.004. PubMed DOI

Shahmansouri N., Cartier R., Mongrain R. Characterization of the toughness and elastic properties of fresh and cryopreserved arteries. Journal of Biomechanics. 2015;48(10):2205–2209. doi: 10.1016/j.jbiomech.2015.03.033. PubMed DOI

Rigol M., Heras M., Martínez A., et al. Changes in the cooling rate and medium improve the vascular function in cryopreserved porcine femoral arteries. Journal of Vascular Surgery. 2000;31(5):1018–1025. doi: 10.1067/mva.2000.103793. PubMed DOI

Karlsson J. O., Toner M. Long-term storage of tissues by cryopreservation: critical issues. Biomaterials. 1996;17(3):243–256. doi: 10.1016/0142-9612(96)85562-1. PubMed DOI

Vischjager M., van Gulik T. M., van Marle J., Pfaffendorf M., Jacobs M. J. H. M. function of cryopreserved arterial allografts under immunosuppressive protection with cyclosporine A. Journal of Vascular Surgery. 1996;24(5):876–882. doi: 10.1016/S0741-5214(96)70026-5. PubMed DOI

Kubíková T., Kochová P., Brázdil J., et al. The composition and biomechanical properties of human cryopreserved aortas, pulmonary trunks, and aortic and pulmonary cusps. Annals of Anatomy - Anatomischer Anzeiger. 2017;212:17–26. doi: 10.1016/j.aanat.2017.03.004. PubMed DOI