A Suggestion of New Integrated Prognostic Fa c tor for Aortic Aneurysm : Ta n gential Stress Index 1

aortic aneurysm is also increasing (1). Recent studies have shown that abdominal aortic aneurysms were detected in 4% of men and women between 65 and 80 years old and 11% of men aged 60 or over (2-5). An aortic aneurysm can be readily detected by measuring aortic diameter; dilatation of 50% or more than expected value, or that of the proximal segment, indicates its presence (6). However, the rupture of an aortic aneurysm is a sudden crisis, and the aneurysm is seldom symptomatic before rupture (1). In previous studies, 42 62% of cases of ruptured aneurysm resulted in the patient’s death before reaching the emergency room (7-9 ) . Surgical mortality rates were reported to be between 32% and 70% (8,10,11). The overall mortality of abdominal aortic aneurysm rupture is said to be around 80 90% (7,9,12). Furthermore, because of multifactorial circumstances, it is not easy to detect a representative predictive factor for aortic aneurysm rupture. By integrating blood pressure, aneurysmal luminal diameter, and wall thickness for the prediction of aortic aneurysm rupture and the guidance of proper practice, we have therefore attempted to establish a new basis for prognosis. In this study, we suggest that the tangential stress index of aortic aneurysm can be a useful prognostic factor for true aortic aneurysms. J Korean Radiol Soc 1999;40:1 0 77-1 0 8 5