Analysis of axial prestretch in the abdominal aorta with reference to post mortem interval and degree of atherosclerosis

Abstract

It is a well-known fact that the length of an artery in situ and the length of an excised artery differs. Retraction of blood vessels is usually observed. This prestretch plays an important role in arterial physiology. Recently we have found the decrease of axial prestretch in human abdominal aorta is so closely correlated with age to be suitable for forensic applications (estimation of the age at time of death for cadavers of unknown identity). Since post mortem autolysis may affect a reliability of an estimate based on axial prestretch, the present study aims to detailed analysis of the effect of post mortem time. Abdominal aorta is a prominent site of atherosclerotic changes (ATH) which potentially may affect longitudinal prestretch. Thus ATH was also involved in the analysis. Axial prestretch in human abdominal aorta, post mortem interval (PMI), and the degree of ATH were documented in 365 regular autopsies. At first data was age adjusted to remove supposed correlation between age and ATH. After the age adjustment of the sample, the correlation analysis showed no significant effect of PMI on the prestretch in non-putrefied bodies. Analysis of variance of the prestretch with respect to ATH suggested that ATH is not suitable factor to explain variability in the prestretch remaining after the age adjustment. This is in accordance with the hypothesis that medial elastic lamellae, vulnerable to Monckeberg sclerosis rather than to atherosclerotic plaques, are responsible for bearing the prestretch.