Longitudinal Analysis of Imaging Features of the Aortic Wall in Patients Diagnosed with an Aortic Dissection

Background The presence of an aortic intimal flap is often identified following an acute aortic dissection (AD). However, the changes that take place in the dissected aorta have not been well characterized in late stage medically managed dissections in the descending thoracic aorta. The objective of this study is to evaluate the temporal changes observed on CT scans that take place in the aorta following an AD. Methods Patients were identified using ICD10 codes (I71.0) for aortic dissection. Inclusion criteria included persistent dissection distal to the left subclavian and CTA performed at the time of diagnosis and serially over a minimum of two years. Imaging features assessed include other affected arteries, wall morphology, (aortic wall thickness, calcification, irregularity), maximum diameter, and false lumen thrombosis. Results The mean age of the 44 aortic dissection patients meeting inclusion criteria was 59 years. The presence of luminal projections and ulcer-like-projections both significantly increased in the descending thoracic aorta over time (p=0.02 and p=0.003, respectively). The thoracic aortic wall appeared significantly more calcified at the time of the latest follow up scan (p=0.015). Additionally, increased frequency of descending thoracic and infrarenal aortic aneurysms were identified on CT scans in patients with long-term follow up (p=0.032 and p=0.018, respectively). Conclusion Following an AD, the aortic wall undergoes significant changes over time including dilation, calcification, and wall irregularity. Additionally, resolution of the traditional double barrel appearance of an AD can occur and obscure the imaging history of the dissection event.