Engineering analysis of aortic wall stress and root dilatation in the V-shape surgery for treatment of ascending aortic aneurysms

• Type of Material: Article
• Authors: Hai Dong, Emory University; Minliang Liu, Emory University; Tongran Qin, Emory University; Liang Liang, University of Miami; Bulat Ziganshin, Yale University School of Medicine; Hesham Ellauzi, Yale University School of Medicine; Mohammad Zafar, Yale University School of Medicine; Sophie Jang, Yale University School of Medicine; John Elefteriades, Yale University School of Medicine; Wei Sun, Emory University
• Language: English
• Date: 2022-02-03
• Publisher: European Association for Cardio-thoracic Surgery
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/icvts/ivac004
• Title of Journal or Parent Work: Interactive Cardiovascular and Thoracic Surgery
• Volume: 34
• Issue: 6
• Start Page: 1124
• End Page: 1131
• Grant/Funding Information: This study is in part supported by American Heart Association (AHA) 18TPA34230083.
• Keywords: Aortic root; Finite element analysis; Ascending aneurysm; V-shape surgery; Wall stress
• Research Categories: Engineering, Biomedical

Abstract

OBJECTIVES The study objective was to evaluate the aortic wall stress and root dilatation before and after the novel V-shape surgery for the treatment of ascending aortic aneurysms and root ectasia. METHODS Clinical cardiac computed tomography images were obtained for 14 patients [median age, 65 years (range, 33–78); 10 (71%) males] who underwent the V-shape surgery. For 10 of the 14 patients, the computed tomography images of the whole aorta pre- and post-surgery were available, and finite element simulations were performed to obtain the stress distributions of the aortic wall at pre- and post-surgery states. For 6 of the 14 patients, the computed tomography images of the aortic root were available at 2 follow-up time points post-surgery (Post 1, within 4 months after surgery and Post 2, about 20–52 months from Post 1). We analysed the root dilatation post-surgery using change of the effective diameter of the root at the two time points and investigated the relationship between root wall stress and root dilatation. RESULTS The mean and peak max-principal stresses of the aortic root exhibit a significant reduction, =0.002 between pre- and post-surgery for both root mean stress (median among the 10 patients presurgery, 285.46 kPa; post-surgery, 199.46 kPa) and root peak stress (median presurgery, 466.66 kPa; post-surgery, 342.40 kPa). The mean and peak max-principal stresses of the ascending aorta also decrease significantly from pre- to post-surgery, with =0.004 for the mean value (median presurgery, 296.48 kPa; post-surgery, 183.87 kPa), and =0.002 for the peak value (median presurgery, 449.73 kPa; post-surgery, 282.89 kPa), respectively. The aortic root diameter after the surgery has an average dilatation of 5.01% in total and 2.15%/year. Larger root stress results in larger root dilatation. CONCLUSIONS This study marks the first biomechanical analysis of the novel V-shape surgery. The study has demonstrated significant reduction in wall stress of the aortic root repaired by the surgery. The root was able to dilate mildly post-surgery. Wall stress could be a critical factor for the dilatation since larger root stress results in larger root dilatation. The dilated aortic root within 4 years after surgery is still much smaller than that of presurgery.