Absence of elastica from inner half of aorta. Multiple dissecting aneurysms.

Multiple dissecting aneurysms were found in the course of an autopsy on a 52-year-old male patient who had expired suddenly as a result of a massive pericardial tamponade. Two of these aneurysms involved the aorta. The others involved muscular arteries, namely, the superior mesenteric and the splenic. In the case of the aorta, there was an absence of elastica from the entire inner half of the media, leaving the fabric of the outer half intact. The course of dissection in the case of each aneurysm lay along the line of demarcation separating the inner from the outer half of the media. This very unusual pattern, showing an absence of elastic lamina in the inner half of the media, differs remarkably from the changes that are commonly seen in dissecting aneurysms of this large elastic artery. Neither the etiology nor pathogenesis of this defect is known. The recognition that such a disease exists is only the first step toward its solution.