Human Anatomical Database for Forensic Analysis of Pre‐Mortem versus Post‐Mortem Exsanguination

Abstract

This study was performed to address questions raised by an exsanguination homicide and to better understand the circumstances and patterns associated with cases of extreme blood loss. Few datasets applicable to exsanguination cases exist in the literature; thus, this work is also intended to expand the resources available for understanding human blood loss and blood removal more generally. A comprehensive dataset was generated analyzing variation in blood evacuation within a set of fourteen vascular structures from 105 human cadaveric bodies. Bodies were stored and embalmed using a standardized methodology, with both superficial and deep vessels, across a wide size range. Vessels were dissected and assessed for the presence of residual blood post‐embalming. Because the blood was flushed as part of the embalming procedure itself, these measurements are indicative of blood evacuation in a fresh tissue specimen (i.e. prior to embalming). Even with multiple points of perfusion, an external pump, and large volumes of embalming fluid, most vessels remained unevacuated of blood in all individuals.The intercostal arteries were by far the most commonly evacuated vessels, where a refined approach found that the fourth right posterior intercostal artery was empty of blood in over 30% of cases. The next most commonly evacuated vessels were the cephalic vein (3.81% aggregate) and the right coronary artery (RCA) (2.86% aggregate, 8.57% 2018 subset). Atria were individually empty at comparatively high rates (12.9%) but only in three cases were both the right and left atria empty in the same individual. A few sampled cardiovascular structures have significantly correlated rates of evacuation, though the correlation coefficients are not large. Cephalic and basilic vein evacuation are coupled (Pearson Coefficient of 0.56, p<0.0001), which is likely a result of their similar function, depth, and size. Atrial evacuation was correlated with both intercostal artery evacuation and RCA evacuation. Asymmetry in evacuation rates was noted between the left and right IJV (5.9% and 2.9%, respectively) and the left and right coronary arteries (0% and 8.6%, respectively). These patterns might be the result of asymmetry in injection site, anatomical asymmetry, or an interaction of the two factors.The overall aggregate rate of evacuation per vascular structure was only 1.97%. It was concluded that complete or nearly complete evacuation of intravascular blood volume is effectively impossible in a post‐mortem context without extraordinary circumstances. In conjunction with other lines of evidence, this controlled dataset could be useful as one standard of comparison for future cases involving death due to exsanguination. This database may also be of interest to anyone performing embalming, utilizing cadaveric human donors in medical education, or utilizing cadaveric samples as proxies for understanding vascular health.Support or Funding InformationAccess to donors and permission for their use in research was graciously provided by the Anatomical Gift Program of USC