Existence of abdominal aortic aneurysms in patients with thoracic aortic dissections

Objective: The objective of this study was to determine the coexistence or later development of pararenal and infrarenal abdominal aortic aneurysms (AAAs) in patients with thoracic aortic dissections. Methods: One hundred forty-five patients (95 men, 50 women) encountered from 1992 to 2001 with thoracic aortic dissections-excluding those associated with trauma, those with Marfan's syndrome, and those with thoracoabdominal aortic aneurysms-were studied. The most common risk factors included hypertension (59%) and a history of tobacco use (52%). Type III dissections affected 86 patients (59%), and type I dissections affected the remaining 59 patients (41%). Aortic computed tomography (CT) scans were obtained annually. Data were assessed by univariate and multivariate analyses. Results. Five patients (3%) had a history of AAA repair prior to their thoracic aortic dissection diagnosis-3 were type III dissections and 2 were type I dissections. Twelve patient's (8%) AAAs were diagnosed with the initial CT study of their thoracic aortic dissection. Type III dissections accounted for all but one of these (11 of 12, 92%). Ten additional AAAs (7%) developed in the 128 patients with no initial evidence of an AAA being recognized from 1 to 48 months (average 16 months) after the thoracic aortic dissection was diagnosed. Type III dissections affected 8 of these 10 patients. Among the total 27 AAAs noted in this series, 74% (20 AAAs) were not continuous with the thoracic aortic dissection. In the univariate analysis, age (P = .0002), male gender (P = .044), history of smoking (P = .01), chronic obstructive pulmonary disease (P < .001), duration of dissection (P = .05), and presence of type III dissection (P = .009) were associated with the presence of an AAA. In the multivariate analysis, both chronic obstructive pulmonary disease (odds ratio 5.4, 95% CI, 1.3 to 22.3; P = .02) and age (OR 1.06, 95% CI, 1.02 to 1.11; P = .004) were significant predictors of the development of AAAs. Conclusion: This study documented that patients with thoracic aortic dissections are at risk to harbor or develop a later AAA. This finding supports the tenet that abdominal CTs or ultrasound scanning should be mandatory in the follow-up of patients with known thoracic aortic dissections.