Ascending aortic volume: A feasible indicator for ascending aortic aneurysm elective surgery?

Diameter-based criterion have been widely adopted for preventive surgery of ascending thoracic aortic aneurysm (ATAA). However, recent and growing evidence has shown that diameter-based methods may not be sufficient for identifying patients who are at risk of an ATAA. In this study, fluid-structure inter-action (FSI) analysis was performed on one-hundred ATAA geometries reconstructed from clinical data to examine the relationship between hemodynamic conditions, ascending aortic volume (AAV), ascending aortic curvature, and aortic ratios measured from the reconstructed 3D models. The simulated hemody-namic and biomechanical parameters were compared among different groups of ATAA geometries classi-fied based on AAV. The ATAAs with enlarged AAV showed significantly compromised hemodynamic con-ditions and higher mechanical wall stress. The maximum oscillatory shear index (OSI), particle residence time (PRT) and wall stress (WS) were significantly higher in enlarged ATAAs compared with controls (0.4 98 [0.4 97, 0.4 99] vs 0.4 99 [0.4 98, 0.4 99], p = 0.002, 312.847 [207.445, 519.391] vs 996.047 [6 40.6 44, 1573.140], p < 0.001, 769.680 [668.745, 879.795] vs 1072.0 0 0 [873.060, 1280.0 0 0] kPa, p < 0.001, respec-tively). Values were reported as median with interquartile range (IQR). AAV was also found to be more strongly correlated with these parameters compared to maximum diameter. The correlation coefficient between AAV and average WS was as high as 0.92 (p < 0.004), suggesting that AAV might be a feasible risk identifier for ATAAs.Statement of Significance Ascending thoracic aortic aneurysm is associated with the risk of dissection or rupture, creating life-threatening conditions. Current surgical intervention guidelines are mostly diameter based. Recently, many studies proposed to incorporate other morphological parameters into the current clinical guide-lines to better prevent severe adverse aortic events like rupture or dissection. The purpose of this study is to gain a better understanding of the relationship between morphological parameters and hemody-namic parameters in ascending aortic aneurysms using fluid-solid-interaction analysis on patient-specific geometries. Our results suggest that ascending aortic volume may be a better indicator for surgical inter-vention as it shows a stronger association with pathogenic hemodynamic conditions.& COPY; 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study used fluid-structure interaction analysis to investigate the relationship between morphological parameters and hemodynamic conditions in ascending aortic aneurysms. The results suggest that enlarged ascending aortic volume is associated with compromised hemodynamic conditions and higher mechanical wall stress.