Author/Authors :
Zuo, Heng School of Mathematics - Sichuan Normal University - Chengdu, China , Ling, Yunfei Department of Cardiovascular Surgery - West China Hospital - Sichuan University - Chengdu, China , Li, Peng West China Hospital - Sichuan University - Chengdu, China , An, Qi Department of Cardiovascular Surgery - West China Hospital - Sichuan University - Chengdu, China , Zhou, Xiaobo School of Biomedical Informatics - University of Texas Health Science Center at Houston - Houston, USA
Abstract :
Some adult patients with Tetralogy of Fallot (TOF) were found to simultaneously develop ascending aortic dilation.
Severe aortic dilation would lead to several aortic diseases, including aortic aneurysm and dissection, which seriously affect
patients’ living quality and even cause patients’ death. Current practice guidelines of aortic-dilation-related diseases mainly focus
on aortic diameter, which has been found not always a good indicator. Therefore, it may be clinically useful to identify some
other factors that can potentially better predict aortic response to dilation. Methods. 20 TOF patients scheduled for TOF repair
surgery were recruited in this study and were divided into dilated and nondilated groups according to the Z scores of ascending
aorta diameters. Patient-specific aortic CT images, pressure, and flow rates were used in the construction of computational
biomechanical models. Results. Simulation results demonstrated a good coincidence between numerical mean flow rate at inlet
and the one obtained from color Doppler ultrasonography, which implied that computational models were able to simulate the
movement of the aorta and blood inside accurately. Our results indicated that aortic stress can effectively differentiate patients of
the dilated group from the ones of the nondilated group. Mean ascending aortic stress-P1 (maximal principal stress) from the
dilated group was 54% higher than that from the nondilated group (97.97 kPa vs. 63.47 kPa, p value = 0.044) under systolic
pressure. Velocity magnitude in the aorta and aortic wall displacement of the dilated group were also greater than those of the
nondilated group with p value < 0.1. Conclusion. Computational modeling and ascending aortic biomechanical factors may be
used as a potential tool to identify and analyze aortic response to dilation. Large-scale clinical studies are needed to validate
these preliminary findings.
