How did the dissecting aneurysm get its name?

Dissecting aneurysm gets its name due to the separation the dissection creates between arterial layers. This phenomenon mimics when one part of one page on a book gets slightly bent away and separated from the paper. If we now place that bent corner between our nails and start separating both halves, a dissection starts, in this case involving paper layers, rather than layers of artery walls within a vessel or the layers of the aorta.