Acute Aortic dissection is a deadly condition. A patient need immidiate medical care to survive. Depending on where the dissection occurrs on the aorta, how it develops, and many other things, a patient can die within minutes, or survive. It is not easy to give a general prognosis, more than that chanses for survival increases significantly if the patient is brought to advanced medical care immidiatley.
Having had medical care, many patients can live up to 5, 10, 20 or even more years. This is also very individual, depending on how the dissection occurred and how it was treated, among many other factors influencing survival after getting ill. Such things can be need of further surgery, complications in organs due to the initial dissection etc etc.