Changes in aortic arch geometry and the risk for Stanford B dissection

BACKGROUND: The increase in aortic diameter is not closely associated with type B aortic dissection (TBAD); morphological risk factors other than aortic diameter may help to better identify patients at risk for TBAD. The purpose of this study was to investigate possible morphological factors associated with the occurrence of TBAD. METHODS: This study was a retrospective, multicenter, cross-sectional study. We collected 94 patients with TBAD as the TBAD group and 534 patients with healthy aortas as the healthy control group. Morphometric data were collected on three-dimensional models of the thoracic aorta. A propensity score matching (PSM) analysis was conducted to reduce the potential for confounding by baseline factors. RESULTS: The number of patients in the TBAD group was 75 after PSM. Longer lengths of the aortic arch (28.00±7.42 vs. 25.14±7.11 cm) were observed in patients with TBAD. The width (80.04±17.27 vs. 71.73±15.55 mm) and height (24.92±11.39 vs. 19.37±10.10 mm) of the aortic arch in patients with TBAD were both larger than those of healthy controls. The morphological changes associated with the occurrence of type B acute dissection were most pronounced in the geometry of the aortic arch. CONCLUSIONS: This study demonstrates that TBAD was associated with longer lengths of aortic arch and with larger arch height and width.