An autopsy case series on adventitial hemorrhages at the junction of aorta and posterior intercostal arteries - a potential mechanism of appearance.

Recently, a novel autopsy finding in deaths by hanging was reported - adventitial hemorrhages of the descending aorta at the junction with the posterior intercostal arteries. The suggested mechanism of appearance is the axial traction of the body on neck compression but also agonal convulsion-related repetitive spine hyperextension, leading to stretching and tearing of the adventitial blood vessels. So, they should appear in other deaths that share these agonal elements with hangings, such as epilepsy-related deaths, drownings, fatal electrocution or hypothermia. We report eight isolated, non-consecutive autopsy cases comprising epilepsy-related death (n = 1), electrocution (n = 1), drowning (n = 2), hypothermia (n = 1), and hanging (n = 2), where death involved exactly either agonal tonic-clonic seizures or other mechanical traction of the intercostal arteries, and severe thoracoabdominal trauma (n = 1), with mechanical latero-lateral traction of the intercostal arteries. In all eight cases, fresh adventitial hemorrhages were macroscopically visible as dark-red round to oval foci at the artery junctions and were confirmed by light microscopy. Histology revealed that, in addition to confluent adventitial hemorrhages, the microscopic subadventitial tear with fresh hemorrhage could be observed in some. The congested adventitial vasa vasorum in the proximity of these hemorrhages were observed on the histology samples, as well. This case series contributes to our understanding of adventitial hemorrhages at the junction of descending aorta with the posterior intercostal arteries, and provides insight into their morphology, with implications on the interpretation limitations but also hints to potential mechanism of their appearance, provided these prove to be intravital.