Patient specific stress and rupture analysis of ascending thoracic aneurysms

JOURNAL OF BIOMECHANICS

卷:48

Article

Trabelsi, Olfa¹  Davis, Frances M.¹  Rodriguez-Matas, Jose F.³  Duprey, Ambroise^1,2  Avril, Stephane¹ 

[1] Ecole Natl Super Mines, CIS EMSE, Ctr Biomed & Healthcare Engn, LCG,CNRS UMR5146, F-42023 St Etienne, France

[2] CHU St Etienne, Hop Nord, Cardiovasc Surg Serv, F-42055 St Etienne, France

[3] Politecn Milan, Dipartimento Chim Mat & Ingn Chim Giulio Natta, I-20133 Milan, Italy

关键词: Ascending thoracic aortic aneurysm;    Finite element analysis;    Wall stress;    Rupture risk;    Aneurysm rupture;    Patient specific material properties;   

DOI  :  10.1016/j.jbiomech.2015.04.035

来源: Elsevier

【 摘 要 】

An ascending thoracic aortic aneurysm (ATAA) is a serious medical condition which, more often than not, requires surgery. Aneurysm diameter is the primary clinical criterion for determining when surgical intervention is necessary but, biomechanical studies have suggested that the diameter criterion is insufficient. This manuscript presents a method for obtaining the patient specific wall stress distribution of the ATAA and the retrospective rupture risk for each patient. Five human ATAAs and the preoperative dynamic CT scans were obtained during elective surgeries to replace each patient's aneurysm with a synthetic graft. The material properties and rupture stress for each tissue sample were identified using bulge inflation tests. The dynamic CT scans were used to generate patient specific geometries for a finite element (FE) model of each patient's aneurysm. The material properties from the bulge inflation tests were implemented in the FE model and the wall stress distribution at four different pressures was estimated. Three different rupture risk assessments were compared: the maximum diameter, the rupture risk index, and the overpressure index. The peak wall stress values for the patients ranged from 28% to 94% of the ATAA's failure stress. The rupture risk and overpressure indices were both only weakly correlated with diameter (rho = -0. 29, both cases). In the future, we plan to conduct a large experimental and computational study that includes asymptomatic patients under surveillance, patients undergoing elective surgery, and patients who have experienced rupture or dissection to determine if the rupture risk index or maximum diameter can meaningfully differentiate between the groups. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

Free