Mohammed Alreshidan1, Nastaran Shahmansouri2, Jennifer Chung3, Vynka Lash4, Alexander Emmott2, Richard L Leask2, Kevin Lachapelle5. 1. Department of Cardiac Surgery, McGill University, Montreal, Quebec, Canada; King Salman Heart Center, King Fahad Medical City, Riyadh, Saudi Arabia. 2. Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada. 3. Department of Cardiac Surgery, McGill University, Montreal, Quebec, Canada. 4. Department of Anesthesia, McGill University, Montreal, Quebec, Canada. 5. Department of Cardiac Surgery, McGill University, Montreal, Quebec, Canada. Electronic address: kevin.lachapelle@mcgill.ca.
Abstract
INTRODUCTION: Ex vivo measurement of ascending aortic biomechanical properties may help understand the risk for rupture or dissection of dilated ascending aortas. A validated in vivo method that can predict aortic biomechanics does not exist. Speckle tracking transesophageal echocardiography (TEE) has been used to measure ventricular stiffness; we sought to determine whether speckle TEE could be adapted to estimate aortic stiffness in vivo and compare these findings with those obtained by ex vivo tissue measurements. METHODS: A total of 17 patients undergoing ascending aortic resection were recruited to with a mean aortic diameter was 56.16 ± 15 mm. Intraoperative speckle TEE tracking analysis was used to calculate aortic stiffness index using the following equation: β2=ln(SBP/DBP)/AoS, where β2 is the stiffness index; SBP is systolic blood pressure; DBP is diastolic blood pressure; and AoS is the circumferential strain. Ex vivo stiffness was obtained by mechanical tissue testing according to previously described methods. The aortic ring at the pulmonary trunk was divided into 4 equal quadrants. RESULTS: The in vivo stiffness index for the inner curvature, anterior wall, outer curvature, and posterior wall were 0.0544 ± 0.0490, 0.0295 ± 0.0199, 0.0411 ± 0.0328, and 0.0502 ± 0.0320, respectively. The mean ex vivo 25% apparent stiffness for inner curvature, anterior wall, outer curvature, and posterior wall were 0.0616 ± 0.0758 MPa, 0.0352 ± 0.00992 MPa, 0.0405 ± 0.0199 MPa, and 0.0327 ± 0.0106 MPa, respectively. The patient-matched ex vivo 25% apparent stiffness and in vivo stiffness index were not significantly different (P = .8617, 2-way analysis of variance with repeated measures). CONCLUSIONS: The use of speckle TEE appears to be a promising technique to estimate ex vivo mechanical properties of the ascending aortic tissue.
INTRODUCTION: Ex vivo measurement of ascending aortic biomechanical properties may help understand the risk for rupture or dissection of dilated ascending aortas. A validated in vivo method that can predict aortic biomechanics does not exist. Speckle tracking transesophageal echocardiography (TEE) has been used to measure ventricular stiffness; we sought to determine whether speckle TEE could be adapted to estimate aortic stiffness in vivo and compare these findings with those obtained by ex vivo tissue measurements. METHODS: A total of 17 patients undergoing ascending aortic resection were recruited to with a mean aortic diameter was 56.16 ± 15 mm. Intraoperative speckle TEE tracking analysis was used to calculate aortic stiffness index using the following equation: β2=ln(SBP/DBP)/AoS, where β2 is the stiffness index; SBP is systolic blood pressure; DBP is diastolic blood pressure; and AoS is the circumferential strain. Ex vivo stiffness was obtained by mechanical tissue testing according to previously described methods. The aortic ring at the pulmonary trunk was divided into 4 equal quadrants. RESULTS: The in vivo stiffness index for the inner curvature, anterior wall, outer curvature, and posterior wall were 0.0544 ± 0.0490, 0.0295 ± 0.0199, 0.0411 ± 0.0328, and 0.0502 ± 0.0320, respectively. The mean ex vivo 25% apparent stiffness for inner curvature, anterior wall, outer curvature, and posterior wall were 0.0616 ± 0.0758 MPa, 0.0352 ± 0.00992 MPa, 0.0405 ± 0.0199 MPa, and 0.0327 ± 0.0106 MPa, respectively. The patient-matched ex vivo 25% apparent stiffness and in vivo stiffness index were not significantly different (P = .8617, 2-way analysis of variance with repeated measures). CONCLUSIONS: The use of speckle TEE appears to be a promising technique to estimate ex vivo mechanical properties of the ascending aortic tissue.
Authors: William M Torres; Julia Jacobs; Heather Doviak; Shayne C Barlow; Michael R Zile; Tarek Shazly; Francis G Spinale Journal: Am J Physiol Heart Circ Physiol Date: 2018-07-13 Impact factor: 4.733
Authors: Ali Alakhtar; Alexander Emmott; Cornelius Hart; Rosaire Mongrain; Richard L Leask; Kevin Lachapelle Journal: BMJ Simul Technol Enhanc Learn Date: 2021-06-21
Authors: Maria C Palumbo; Lisa Q Rong; Jiwon Kim; Pedram Navid; Razia Sultana; Jonathan Butcher; Alberto Redaelli; Mary J Roman; Richard B Devereux; Leonard N Girardi; Mario F L Gaudino; Jonathan W Weinsaft Journal: PLoS One Date: 2020-03-12 Impact factor: 3.240