This study is testing a special device called the **ASG device** to treat a condition known as **Type A aortic dissection**. This is a serious problem where the large blood vessel (aorta) from the heart tears. The study is for people at high risk for open surgery, meaning surgery on the chest is risky for them. Participants will have the ASG device placed inside the aorta instead of having open surgery. **Key Points:** - **Length of Study:** Participants need to agree to follow-ups for up to 5 years. - **Visits Needed:** Participants will need to come for regular check-ups, including imaging tests. - **Eligibility:** Must be over 18, have a suitable aorta anatomy, and meet specific health criteria. People with certain health conditions or who are pregnant cannot join. This study aims to make the treatment safer and more effective for those who can't have traditional surgery. Participants must provide informed consent to join the study.