Aortic elongation in aortic aneurysm and dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project.

OBJECTIVES: To study the lengths and diameters of aortic segments in healthy and diseased aortas and to assess the role of aortic elongation in Type A aortic dissection (TAD) prediction. METHODS: Ectasia and aneurysm were defined by ascending aorta diameters of 45-54mm and >= 55mm, respectively. Computed tomography angiography studies of 256 healthy, 102 ectasia, 38 aneurysm, 17 pre-TAD and 166 TAD aortas were analysed using curved multiplanar reformats. RESULTS: The study groups were structurally equal. The diameter of the ascending aorta was 35mm in the control group and was larger (P < 0.001) in the pre-TAD (43mm) and TAD (56mm) groups. The length of the ascending aorta from the aortic annulus to the brachiocephalic trunk was 92mm in the control group, 113mm in the ectasia group, 120mm in the aneurysm group and 111mm and 118mm in the pre-TAD and TAD groups (all P < 0.001 compared with the control group). An ascending aorta length of 120mm was exceeded in 2% of the control group, 31% of the ectasia group, 50% of the aneurysm group, 24% of the pre-TAD group and 48% of the TAD group. The correlation between the diameter and the length of the ascending aorta was r = 0.752; therefore, both parameters must be examined separately. A score considering both parameters identified 23.5% of pre-TAD patients, significantly more than the diameter alone, and 31.4% of ectasia aortas were elongated. CONCLUSIONS: Patients with ectatic (45-54mm diameter) and elongated (> 120 mm) ascending aortas represent a high-risk subpopulation for TAD.