The goal of this observational study is to collect clinical information on how safe, and how well the NEXUS Aortic Arch Stent Graft System and the Custom-Made NEXUS DUO™ Aortic Arch Stent Graft System work for the treatment of aortic aneurysms, in the standard-of-care setting.

The main question[s] it aims to answer are:

• Early mortality
• Safety outcomes throughout the study
• Device failure throughout the study
• Procedural and hospitalisation information Participants will be treated per institutional standard of care Follow-up information will be collected through to five years.

1. Male and female age ≥18 years
2. The subject is indicated for implant of the NEXUS Aortic Arch System in accordance with the current IFU, or
3. The subject is indicated for implant of the custom-made NEXUS DUO Aortic Arch System in accordance with the current IFU, or
4. The subject has been already implanted, after February 2019, with the NEXUS or the NEXUS DUO according to the relevant IFU
5. The subject is able and willing to provide informed consent to participate in the study.
6. Subject is not currently enrolled in another investigational study or registry that would directly interfere with the current study, except if the subject is participating in a mandatory government registry, or a purely observational registry with no associated treatments. Each instance should be brought to the attention of the sponsor to determine eligibility.
7. In the opinion of the Investigator, life expectancy exceeds one year
8. The subject is not pregnant or planning to become pregnant.
9. In the physician's opinion, subject's renal function is stable for the NEXUS procedure.
10. In the opinion of the investigator, subject does not have co-morbidities or planned surgeries that will interfere with the implant of the device, e.g., major cardiac surgery or interventional procedure in the last 90 days, MI or cerebral vascular accident (CVA) in the last 90 days

Patients diagnosed with a thoracic aortic aneurysm or chronic dissection extending to or involving the aortic arch and who are considered candidates for the endovascular repair.