Effect of Sex on Biomechanical Properties of the Proper Hepatic Artery in Pigs and Humans for Liver Xenotransplant

Abstract

Objectives: This study investigated the relation between biomechanical properties of the proper hepatic artery and sex in pigs and humans to provide the theoretical basis for selecting suitable donor in pig-to-human liver xenotransplant. Materials and Methods:The proper hepatic arteries of 32 Chinese Hubei white pigs (8 males, 8 females, 8 castrated males, and 8 ovariectomized females) and 10 deceased donors (5 human men, 5 human women) were obtained. The pressure-diameter relations of the proper hepatic arteries were measured on biomechanical test equipment to calculate the incremental elastic modulus (E inc ), pressure-strain elastic modulus (E p ), volume elastic modulus (E v ), and compliance. Each sample was sliced into 5-µm frozen sections and stained with hematoxylin-eosin. Results: There were significant differences in E inc (F=10.24; P = .001), E p (F=3.75; P = .001), and E v (F=3.41; P = .002) of the proper hepatic arteries of female, male, and gonadectomized pigs; females had the lowest elastic modulus and the gonadectomized group had the highest (P < .01). There was a significant difference in compliance of the porcine proper hepatic arteries between the sexes, highest in the female group and lowest in the gonadectomized group (P < .01). No difference in the elastic modulus and compliance of the proper hepatic artery between the male pig and the human man. There was no difference between the female pig and the human woman. Conclusions: There were differences in the biomechanical properties of the proper hepatic arteries of the female, male, and gonadectomized pigs. The biomechanical properties of the human men/women proper hepatic artery match those of the porcine male/female hepatic artery. The correlation between sex and biomechanical properties of the proper hepatic artery in pigs could imply that a pig of the same sex should be chosen for pig-to-human liver xenotransplant.

Dependence of ablative ability of high-intensity focused ultrasound cavitation-based histotripsy on mechanical properties of agar

“…As a comparison, heptocellular carcinoma tumors were reported to have a range of 20.4-75 kPa, and metastatic liver tumors may have a range of 23.6-75 kPa (Masuzaki et al, 2007). Likewise, normal liver tissue ranges from $15 kPa to $1 MPa depending on the applied strain (Rosen et al, 2008;Umale et al, 2013) while the elasticity of the hepatic veins and arteries is $30 kPa at normal blood pressure (Wang et al, 2009a;Li et al, 2012). We did not extend the modulus beyond 250 kPa as our earlier study showed that the therapy became independent of stiffness at higher stiffness values (Xu and Bigelow, 2011).…”