We describe two previously unreported associations in four cases. The first two cases demonstrate an association between segmental mediolytic arteriopathy and vascular Ehlers-Danlos syndrome. The second two cases illustrate an association between vascular Ehlers-Danlos syndrome and traumatic subarachnoid hemorrhage. In case 1, there was acute subarachnoid hemorrhage and mesenteric artery dissection. In case 2, there was an acute mesenteric artery dissection with intestinal infarction. In both cases 1 and 2, segmental mediolytic arteriopathy was found in the vertebral arteries. Cases 3 and 4 were sudden deaths from traumatic subarachnoid hemorrhage with intracranial vertebral artery rupture. Genetic testing in all four cases revealed point mutations in the type 3 procollagen gene (COL3A1), as observed in vascular Ehlers-Danlos syndrome. Based on the first two cases, we propose that segmental mediolytic arteriopathy may be a marker for this disease. We further suggest that vascular Ehlers-Danlos syndrome may be related to the pathogenesis of traumatic vertebral artery injury, in some cases. We recommend that cases of segmental mediolytic arteriopathy and traumatic subarachnoid hemorrhage undergo genetic testing for COL3A1 mutations.