Traumatic vertebral artery injury: detailed clinicopathologic and morphometric analysis of 6 cases.

Traumatic vertebral artery injury is frequently fatal from what may often be mild trauma to the head and neck. Detailed examination of vertebral arteries is not frequently undertaken at autopsy: the structural and histologic changes that may be relevant to the development of the injury are not well known. We sampled vertebral arteries bilaterally from 6 forensic autopsies (age = 26-50 years; 3 of 6 suffered from alcohol toxicity) with documented intradural vertebral artery injuries, and 4 nonvertebral-artery-injury-related autopsies (age = 19-70 years). Intradural, dural, and extradural components from each artery were submitted for paraffin-embedded tissue processing. Multiple serial sections and special stains (hematoxylin and eosin, alcian blue pH 2.5, reticulin, Congo red) were independently examined by 2 pathologists. All 6 of 6 injured samples and 4 of 4 control samples showed degenerative changes (intimal fibrosis, focal disruption of the internal elastic lamina, and medial calcification). However, microscopic adventitial hemorrhages were only observed around peripheral nerves adjacent to the injured samples. These may be due to tracking of blood along perineural loose connective tissue regions of reduced resistance, and may be a useful finding that points to underlying vertebral artery injury. Thus, careful dissection and gross and microscopic, examination of the vertebral arteries, with particular attention to the intracranial segments, is recommended in all cases of fatal traumatic head and neck injuries.