PhD Scientific Days 2026

Poster Session 2.T - Surgical Medicine

Effect of Thawing Protocols on the Mechanical Properties of Cryopreserved Human Arterial Allografts

Name of the presenter

Kovács, Gergely Imre

Institute/workplace of the presenter

Semmelweis University Deptartment of Vascular and Endovascular Surgery

Authors

Dr. Gergely Imre Kovács¹, Dr. László Hidi PhD.², Dóra Haluszka PhD.³, Evelin Forró PhD.³
1: Semmelweis University Deptartment of Vascular and Endovascular Surgery
2: Department of Vascular and Endovascular Surgery, Semmelweis University
3: Department of Biophysics and Radiation Biology, Semmelweis University

Text of the abstract

Introduction: An operation under septic conditions presents significant challenges in vascular surgery: graft infection is a serious risk after synthetic graft implantation. In these complicated cases, an infection-resistant alternative is essential to minimize the chance of reinfection. Cryopreserved vascular allografts can provide a suitable alternative. Unfortunately, there are no international guidelines for the preparation, storage, or thawing of these vessel grafts. Previous publications have pointed out the effect of rapid thawing on structural changes, but no functional changes were observed during the conducted strain tests.

Aims: We aimed to compare the mechanical properties of cryopreserved human arterial samples after using three different thawing protocols.

Method: During multiorgan donations, common femoral artery samples were harvested from 10 human donors. Samples were cryopreserved in a 10 v/v % dimethyl sulfoxide solution and stored at -80 °C. As a reference, samples were examined from each donor before cryopreservation (BC). After cryopreservation, three different thawing methods were performed: 37 °C water bath (T1); two-step thawing: preconditioning at room temperature for 20 minutes, then 37 °C water bath (T2); 4 °C water bath (T3). Each sample underwent a uniaxial ring test to characterise its elasticity and tensile strength. Also, the elastic modulus of the tunica adventitia was determined using atomic force microscopy. The results were analysed by Bland-Altman plots.

Results: No significant change was observed regarding the tensile strength (BC 0,1564±0,0521 N/mm3; T1 0,1889±0,0683 N/mm3; T2 0,1820±0,0971 N/mm3; T3 0,2194±0,1048 N/mm3) or elasticity (BC 1,396±0,441; T1 1,381±0,337; T2 1,474±0,435; T3 1,522±0,524) values.
All the examined samples preserved the Young modulus of their adventitia after thawing (BC 4,485±2,141; GPaT1 5,126±3,0763 GPa; T2 4,058±1,978 GPa; T3 3,262±1,591 GPa).

Conclusion: Our results indicate that after our standard cryopreservation protocol, the vascular allografts maintain not only their elasticity and mechanical stability, but also their nanomechanical capabilities, regardless of whether the 37 °C water bath, the preconditioning protocol, or a 4 °C water bath was used. Our results show that these thawing protocols do not affect the mechanical capabilities of cryopreserved human arterial allografts.