Info

Model Score

Figure 2.3A. Observed versus predicted mortality for acute type A aortic dissection based on a risk score; each risk factor was statistically extracted from retrospective analysis in IRAD and then prospectively confirmed. Both predicted and observed mortality rates in IRAD increase with increasing number and weight of risk factors. Adapted from reference 66.

Figure 2.3B. Simple risk prediction scheme for type B dissection. The associated symptoms relate to the individual risk of death and may be used to select a given patient for emergent interventional therapy.

Present surgical techniques target the ascending aortic tear primarily with replacement or repair of the aortic root and the aortic valve apparatus (if necessary). Meanwhile, elimination of the remaining false lumen and potential remodeling of the dissected descending aorta currently play a secondary role.

Replacement or repair of the ascending aorta does not consistently eliminate flow and pressure from the distal false channel. Fewer than 10% of operated type A dissections develop postoperative false lumen obliteration with time52.

TYPE B (DISTAL) DISSECTION

Acute aortic dissection affecting the descending aorta is less lethal in the acute phase than type A dissection but is not strikingly different with respect to clinical presentation. Instantaneous onset of severe back (64%) or chest (63%) pain are frequently reported symptoms, as is sudden abdominal pain (43%). Stroke is less common (21%), and presentation with an ischemic leg or peripheral ischemic neuropathy is encountered on occasion2-4,8,13,66,68,69.

Patients with uncomplicated type B dissection have a 30-day mortality of 10%3 (Figure 2.4). Conversely, those who develop an ischemic leg, renal failure, visceral ischemia, or contained rupture often require urgent aortic repair; their mortality is 20% by day 2 and 25% by one month. Not surprisingly, advanced age, rupture, shock, and malperfusion are the most important indepen-

surgical medical stent-graft

Was this article helpful?

0 0

Post a comment