941 A Systematic Review of Surgical Intervention Criteria for Thoracic Aortic AneurysmsH Neill, S Taylor
Elective surgical repair of thoracic aortic aneurysms (TAAs) is the only treatment that prevents dissection or rupture. Current guidelines from the American College of Cardiology/American Heart Association and the European Society of Cardiology, recommend an aortic diameter threshold of 5.5cm for surgical intervention of TAAs. Recent studies have questioned the efficacy of current guidelines as they highlighted that the majority of dissections occur before reaching the threshold. This review aims to determine if an aortic diameter of 5.5cm is an appropriate threshold for prophylactic surgical repair of non-syndromic ascending TAAs.
A search of Ovid MEDLINE and Pubmed databases was performed. Search terms included “ascending thoracic aortic aneurysm”, “ATAA”, “aortic diameter” and “aortic size paradox”. Non-English papers, animal studies and case reports were excluded. Reference lists from each article were assessed for further literature which met the inclusion criteria.
22 studies were included. Four themes emerged from these papers which support lowering the threshold for prophylactic surgery: quantifying the changes in aortic diameter that occur during dissection, the discovery of the aortic size paradox, the identification of a new hinge point, and the improved safety of modern surgery. Regardless of this evidence, it appears to be unjustified to lower the threshold based on relative risk calculations.
Despite current guidelines, the use of aortic diameter as a risk assessment tool for TAAs is inadequate. Multiple studies have shown the ineffectiveness of a 5.5cm threshold, suggesting revision of current surgical guidelines is warranted.