Invasion of a Shared Space: The Nightmare Roommate.

Shared sheath rupture is a rare manifestation of acute aortic syndrome. An aortic rupture into the common subadventitial space of the great vessels leads to hematoma extension along the pulmonary arterial tree, thus mimicking a pulmonary embolism. We report a case of shared sheath rupture promptly diagnosed on cross-sectional imaging and managed successfully with a root and hemiarch replacement.