It categorizes the dissection based on where the original intimal tear is located and the extent of the dissection (localized to either the ascending aorta or descending aorta or involving both the ascending and descending aorta). Type I – originates in ascending aorta, and propagates at least to the aortic arch and often beyond it distally. It is most often seen in patients less than 65 years of age and is the most lethal form of the disease. Type II – originates in the ascending aorta and is confined to it. Type III – originates in the descending aorta and rarely extends proximally, but will extend distally. It most often occurs in elderly patients with atherosclerosis and hypertension. Stanford
The Stanford classification is divided into two groups, A and B, depending on whether the ascending aorta is involved. A – involves the ascending aorta and/or aortic arch, and possibly the descending aorta. The tear can originate in the ascending aorta, the aortic arch, or more rarely, in the descending aorta. It includes DeBakey types I and II. B – involves the descending aorta or the arch (distal to the left subclavian artery), without the involvement of the ascending aorta.
The tapes used to tie against the ring provide a larger contact surface area than the traditional stitches, thus it provides stronger anastomosis and better surgical results.A number of comorbid conditions increase the surgical risk of repair of an aortic dissection. These conditions include the following:
Prolonged preoperative evaluation (increased length of time prior to surgery)
Advanced age
Comorbid disease states (e.g. : coronary artery disease)
Aneurysm leakage
Cardiac tamponade
Shock - obstructive shock
Past history of myocardial infarction
History of kidney failure (either acute or chronic kidney failure)

Follow-up
The long-term follow-up in individuals who survive aortic dissection involves strict blood pressure control. The relative risk of late rupture of an aortic aneurysm is 10 times higher in individuals who have uncontrolled hypertension, compared to individuals with a systolic pressure below 130 mmHg.The risk of death is highest in the first two years after the acute event, and individuals should be followed closely during this time period. About 29% of late deaths following surgery are due to rupture of either a dissecting aneurysm or another aneurysm. In addition, a 17% to 25% incidence exists of new aneurysm formation, typically due to dilatation of the residual false lumen. These new aneurysms are more likely to rupture, due to their thinner walls.Serial imaging of the aorta is suggested, with MRI being the preferred imaging technique. Prognosis
Of all people with aortic dissection, 40% die immediately and do not reach a hospital in time. Of the remainder, 1% die every hour, making prompt diagnosis and treatment a priority.