Effect of solution and post-mortem time on mechanical and histological properties of liver during cold preservation

Abstract

BACKGROUND:In liver transplantation, the donor and recipient are in different locations most of the time, and longer preservation periods are inevitable. Hence, the choice of the preservation solution and the duration of the preservation period are critical for the success of the transplant surgery. OBJECTIVE: In this study, we examine the mechanical and histological properties of the bovine liver tissue stored in Lactated Ringer's (control), HTK and UW solutions as a function of preservation period. METHODS:The mechanical experiments are conducted with a shear rheometer on cylindrical tissue samples extracted from 3 bovine livers and the change in viscoelastic material properties of the bovine liver is characterized using the fractional derivative Kelvin-Voigt Model. Also, the histological examinations are performed on the same liver samples under a light microscope. RESULTS:The results show that the preservation solution and period have a significant effect on the mechanical and histological properties of the liver tissue. The storage and loss shear moduli, the number of the apoptotic cells, the collagen accumulation, and the sinusoidal dilatation increase, and the glycogen deposition decreases as the preservation period is longer. CONCLUSIONS: Based on the statistical analyses, we observe that the liver tissue is preserved well in all three solutions for up to 11 h. After then, UW solution provides a better preservation up to 29 h. However, for preservation periods longer than 29 h, HTK is a more effective preservation solution based on the least amount of change in mechanical properties. On the other hand, the highest correlation between the mechanical and histological properties is observed for the liver samples preserved in UW solution.

Visuo-Haptic Discrimination of Viscoelastic Materials

“…However, we require fractional order derivatives to model the same relationship in the case of springpot elements. Despite the computational complexity of the fractional order differentiation, rheological models utilizing a springpot element introduces several advantages over the ones composed of springs and dashpots alone (see applications in tissue modeling in [54], [55], [56], for example).…”

A compact 0.5 T MR elastography device and its application for studying viscoelasticity changes in biological tissues during progressive formalin fixation

“…The performance of the new compact MRE device is demonstrated in specimens of liver and brain tissues by studying the effect of formalin fixation on mechanical tissue properties. Fixation effects on tissue structures are highly relevant in pathology and transplantation medicine and have never been addressed using the springpot model, which is the most basic two‐parameter powerlaw in rheology and predicts a linear increase of both storage and loss modulus on logarithmic scales . We employed this model to analyze rheological properties of soft tissues using mechanical constants frequently reported in MRE studies .…”

Viscoelastic properties of shock wave exposed brain tissue subjected to unconfined compression experiments

“…Thus, the high viscosity of the soaked, SWE brain tissue may be due to increased postmortem time or the addition of the absorbed saline solution. This observation is supported by the delayed shear experiments conducted on bovine liver tissue by Ayyildiz et al (2014), where the storage (elastic component) and loss (viscous component) moduli was found to increase as the amount of time stored in a solution increased.…”

“…Porcine brain tissue was also chosen due to its availability, compared to human brain samples. As a result, all tests were completed within 12 hours postmortem to minimize the influence of postmortem time on the material response (Ayyildiz et al, 2014;Bentil and Dupaix, 2014;Garo et al, 2007).…”