If there is an aortic root widening with a dilated ascending aorta, usually the procedure which is done is called the BENTALL procedure.
In Bentall procedure the Aortic valve with the ascending aorta is replaced and the coronary arteries with the button is re-implanted into the graft.
In a small aortic annulus usually to implant a larger sized valve you have to do a root enlargement procedure so that a larger valve can be implanted.
For a given body surface area for a patient the largest valve should be implanted so that the patient is free of symptoms.
Sometimes the patient will have no disease in the valve but the ascending aorta alone needs a replacement. In that case you can do a valve sparing Root replacement operation.
Aortic dissections can occur due to hypertension and sometimes you have to replace the root ascending aorta and the arch etc.