Natural history of penetrating atherosclerotic ulcers in aortic branch vessels

Abstract

ObjectivePenetrating atherosclerotic ulcers (PAUs) in aortic branch vessels are rare. There is a paucity of data regarding their long-term natural history and associated management. This study aimed to determine the prevalence and natural history of aortic branch PAUs. MethodsInstitutional data on all patients with an aortic branch PAU from 2005 to 2020 were retrospectively reviewed. Branch PAUs were defined as any PAU in the iliac, mesenteric, or arch vessels. End points included symptoms, end-organ events, and interventions. All computed tomography angiographies (CTAs) for each patient were reviewed, and total diameter, ulcer width, and ulcer depth were recorded on each computed tomography scan for the branch PAUs. Rate of change was compared between groups (iliac vs arch and visceral vessels) using a linear mixed-effects model. ResultsAmong 58,800 patients who underwent a CTA, 367 patients had an aortic PAU (prevalence: 0.6%) and 58 patients had a branch PAU (prevalence: 0.1%). Among those 58 patients, there were 66 ulcerated branches. There were 50 iliac (42 common iliac, 7 internal, and 1 external), 11 arch (8 left subclavian, 3 innominate), and 5 visceral ulcers (3 superior mesenteric artery, 1 celiac, and 1 renal). Mean age was 74.0 ± 8.8 years, and 86% of patients were male; 74% had hypertension, 79% had hyperlipidemia, and 59% had a concomitant aortic aneurysm. There were 45 PAU vessels with >1 CTA (total of 167 CTAs) with a median follow-up of 4.0 years (interquartile range: 2.0-6.2 years). Total vessel diameter increased in size by 0.27 mm/y but did not differ between groups (iliac vs visceral/arch vessels). PAU width and depth also did not significantly change over time, nor did it differ between groups. No branch PAUs caused symptoms, end-organ events, or rupture, nor required intervention due to symptoms and/or progression. Four PAUs spontaneously resolved (2 iliac, 2 other), and 1 iliac PAU progressed to a saccular aneurysm. ConclusionsThis is one of the largest studies evaluating the natural history of branched PAUs objectively via CTA. Branch PAUs are rare—the prevalence was one-sixth that of aortic PAUs. There was minimal growth noted in a median follow-up of 4 years, and no PAUs required intervention for symptoms or progression. Asymptomatic branch PAUs may be safely observed.