Aortic branch artery pseudoaneurysms accompanying aortic dissection. Part III: natural history

To document the natural history of branch artery pseudoaneurysms (BAPs), which are sequelae of aortic dissection with false lumen thrombosis that have been distinguished anatomically from penetrating ulcers.

Serial computed tomography (CT) scans in 50 patients with at least two CT scans greater than 1 month apart were retrospectively studied. Mean follow-up was 29 months, with longitudinal analyses of 119 BAPs. Changes in BAPs, false lumen thrombosis, and aortic diameter were assessed.

No patient had an aortic rupture or other poor outcome. All BAPs eventually disappeared (ie, thrombosed), with 50% thrombosed within 18 months. Aortas were ectatic, with a mean diameter of 36 mm. There was no statistically significant change in total aortic diameters; however, there was a significant increase in true lumen diameters (P < .0001) and a significant decrease in false lumen thickness (P < .0001) at the level of the BAP over time (mean 50% reduction in maximum thickness of thrombosed false lumen). There were no significant associations between BAP thrombosis and vertebral level, presence of more than one BAP, presence of branch artery in communication with the BAP, history of smoking, diabetes mellitus or hypertension, or treatment with β-blockers, other antihypertensive medication, statins, or anticoagulation therapy. After controlling for other variables, BAPs were less likely to thrombose if an ulcerlike projection was present (P = .003), in men (P = .02), in subjects with hypertension (P = .04), and in older patients (P = .05).

Most BAPs spontaneously thrombose, and associated intramural hematoma regresses/disappears. Isolated BAPs were not associated with poor clinical outcomes.