Disclosed herein are device assemblies for endovascular prosthesis implantation in a human patient comprising a collapsed delivery configuration and an expanded deployed configuration comprising: a stent frame comprising a plurality of expandable stent cells arranged in more than one layer and stacked in a longitudinal direction; a valve attached to the stent frame; and an expandable sealing skirt coupled to the stent frame, the expandable sealing skirt comprising a protruding region configured to expand radially past the stent frame when the device assembly is in the expanded deployed configuration and a non-protruding region.
