False Lumen Treatment for Prevention of Aortic Growth Using Shape Memory Polymer - First-in-Human Study (FLAGSHIP_CHL)

Inclusion Criteria: * ≥18 years of age. * A candidate for false lumen (FL) embolization with a type B dissection, and no prior primary entry tear/TL treatment, OR * A candidate for FL embolization with a type B or type A dissection, in whom the primary entry tear/TL was treated in a previous procedure, and is now presenting with a FL requiring treatment. Exclusion Criteria: * An inability to provide informed consent. * Enrolled in another clinical study other than a registry. * Hyperacute or acute aortic dissection (\<15 days from symptom onset). * Untreated or uncovered primary entry/reentry tear proximal to left subclavian artery (before FL treatment with the investigational product). * Vascular disease, aortic rupture, and/or anatomy and/or dissection membrane condition that precludes the safe access and positioning of an introducer sheath and delivery (and expansion) of the investigational product into the FL. * Prior treatment of the FL. * Planned use of investigational devices to treat the primary entry tear and/or TL. * Absence of/inability to create a reentry tear/fenestration adequately positioned and large enough to allow introducer sheath access into the FL. * Planned use of FL embolic devices other than the investigational product. * Prior abdominal aortic aneurysm (AAA) treatment. * Planned concomitant major surgery (e.g., gastrointestinal surgery). * Diagnosed or suspected congenital degenerative connective tissue disease (e.g., Marfan's or Ehler-Danlos syndr…