| Typology of vascular involvement | Definition |
| Type 1 | Involvement of the branches of the aortic arch |
| Type 2a | Involvement of the ascending aorta, aortic arch and its branches |
| Type 2b | Type 2a plus involvement of thoracic descending aorta |
| Type 3 | Involvement of thoracic descending aorta, abdominal aorta and/or renal arteries |
| Type 4 | Involvement of abdominal aorta and/or renal arteries |
| Type 5 | IIb plus type IV |