1. Aortic Root Biomechanics After Sleeve and David Sparing Techniques: A Finite Element Analysis 
Giordano Tasca, MD, Matteo Selmi, MS, Emiliano Votta, PhD, Paola Redaelli, MD, Francesco Sturla, PhD, Alberto Redaelli, PhD, Amando Gamba, MD 
The Annals of Thoracic Surgery 
Volume 103, Issue 5, Pages (May 2017)
DOI: /j.athoracsur
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Three-dimensional geometric models of aortic root and graft. (A) Physiologic model. (B) Aortic root aneurysm (ARA) model. (C) Sleeve model, consisting of aneurysmal paradigm and bulb-shaped graft. (D) David model, consisting of aortoventricular junction, aortic valve (native aortic wall removed), and bulb-shaped graft. (Dann = diameter of aortoventricular junction, D'ann is the corresponding parameter in the ARA model; Dstj = diameter of sinotubular junction, D'stj is the corresponding parameter in the ARA model; Dl, Dr, Dnc = radial dimension of left, right, and noncoronary sinuses of Valsalva, respectively; h = mean height of Valsalva sinuses; Ll, Lr, Lnc = commissure-commissure distance of left, right, and noncoronary leaflets, respectively; dtube, dmax,bulb, dcollar = graft diameter in tubular, bulb (maximum value), and collar tracts, respectively; dkeyhole = diameter of keyholes.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Leaflet kinematics. (A) Radial position and (B) longitudinal position of nodules of Arantius versus time in physiologic (green line), aortic root aneurysm (ARA) (gray line), Sleeve (red line), and David (blue line) models, respectively. (C) Time-dependent transvalvular pressure acting on ventricular side of aortic leaflets. (D) Leaflet coaptation at td,peak; regions of coaptation are depicted in red, and their extent is reported as percentage of entire leaflet surface. (td,peak = time point of peak diastolic transvalvular pressure; ρNA = radial distance; zNA = longitudinal coordinate.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Effect of graft implantation around aortic tissues in the Sleeve model. Two sectional views: (A) long-axis parasternal view and (B) short-axis view at level of maximum sinus diameter, are reported at unloaded, telediastolic, and systolic configurations. (P = intraluminal pressure.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Leaflet stresses in all 4 models. Spatial distribution of maximum principal stresses acting on aortic leaflets is reported at 3 time points throughout the cardiac cycle. (A) Early systolic ejection. (B) Peak systolic transvalvular pressure. (C) Peak diastolic transvalvular pressure. (D) Time course of maximum principal stresses acting on belly of aortic leaflets; values are averaged over 3 leaflets and, within each leaflet, over 4 points distributed over the leaflet belly, as depicted. (ARA = aortic root aneurysm.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Aortic wall stresses. (A) Maximal principal stresses (SI) acting on commissural insertion line are reported for aortic root aneurysm (ARA), (B) physiological, and (C) Sleeve models. R-L, NC-R and NC-L depict the 3 commissures between right (R), left (L), and noncoronary (NC) leaflets, respectively.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions