Changes in Aortic Wall Thickness at a Site of Entry Tear on Computed Tomography before Development of Acute Aortic Dissection

Objective: To determine if there are changes in the aortic wall before acute aortic dissection (AD) that can be observed on contrast-enhanced computed tomography (CECT). Materials and Methods: Twenty-two patients with AD who underwent CECT before developing AD were retrospectively identified and enrolled as the AD group. Twenty-five consecutive patients who underwent CECT and did not develop AD were enrolled as the control group. In the AD group, the site of entry tear was detected on CECT images; the aortic wall thickness at this site, defined as the dissection-related wall thickness (D-T), was then measured on CECT images acquired before AD. Moreover, the mean thickness of the ascending, thoracic descending, and abdominal aortic walls before AD was defined as the non-dissection-related wall thickness (non-D-T). In the control group, the aortic wall thickness was measured similarly and defined as the control wall thickness (C-T). The D-T, non-D-T, and C-T values were compared using one-way analysis of variance with the Games–Howell pairwise comparison test. Results: The D-T (2.17±0.75 mm) was significantly greater than the non-D-T (1.58±0.22 mm; P<.01) and C-T (1.53±0.15 mm; P<.01). Conclusion: The aortic wall may have become thicker prior to the onset of AD.