Postmortem CT Angiography for Diagnosis of Spontaneous Common Carotid Artery Dissection: An Autopsy Case

Background Postmortem computed tomography angiography (PMCTA) has become increasingly valuable in forensic practice for visualizing vascular rupture sites. Spontaneous common carotid artery dissection (sCCAD) is extremely rare. Knowingly, no previous reports have demonstrated its findings on PMCTA. Here, we report a case in which PMCTA was crucial in determining the cause of death in a man with right-sided sCCAD. Methods A man in his 90s experienced immediate lost consciousness and neck swelling following bathing and was confirmed dead upon hospital arrival owing to cardiopulmonary arrest, with intubation impossible. The patient had no history of neck surgery. Non-contrast CT performed three days postmortem revealed a right-dominant cervical hematoma without airway obstruction. PMCTA was performed during autopsy to identify the bleeding source. After thoracotomy and heart removal, catheters were inserted into the brachiocephalic and left common carotid arteries via the aorta. Gastrografin, a water-soluble contrast agent, was manually injected, followed by helical CT from the head to the upper chest. Results PMCTA demonstrated contrast extravasation from the right common carotid artery and vascular compression caused by a hematoma. Autopsy revealed a circumferential hematoma, predominantly on the right anterior neck. The right common carotid artery showed an adventitial rupture 1.5 cm below the bifurcation and an intimal rupture 1.8 cm below it, with a 1.8 cm dissection between them. Histopathology confirmed adventitial disruption and thinning of the tunica media at the dissection site. The cause of death was hematoma formation due to right-sided sCCAD. Conclusions sCCAD limited to the common carotid artery is rare. This case represents the first report to visualize the rupture site and vascular compression in sCCAD using PMCTA. PMCTA is a valuable adjunct for identifying vascular rupture and estimating the cause of death through three-dimensional vascular assessment.