1. Prosthetic replacement of the aorta is a risk factor for aortic root aneurysm development 
Natascha Simon-Kupilik, MD, Heinz Schima, PhD, Leopold Huber, Reinhard Moidl, MD, Gerhard Wipplinger, Udo Losert, MD, Ernst Wolner, MD, Paul Simon, MD 
The Annals of Thoracic Surgery 
Volume 73, Issue 2, Pages (February 2002)
DOI: /S (01)

2. Fig 1
Computer model of the aortic root and the adjacent structures. The diagram depicts the structure of the numerical simulator. Each vascular segment is represented by its fluid inertia (I), fluid resistance (R), tissue elasticity (E), and tissue viscoelasticity (Ev, Rv). The left ventricle is modeled by a varying pressure source (PLV), varying compliance (CLV), and myocardial resistance (RLV). The valves are represented by rectifiers (DMITR, DAOR) and leakage resistors (RL); the inflow is provided by left arterial pressure (LAP). The peripheral circulation is simulated by similar parameters IP, RP, EVP, RVP, and a concentrated peripheral resistance RP. For the simulation of the prosthetic graft, the compliances (EG, EVG) are reduced to one tenth of the natural value. (g = graft; r = root; a = aorta; p = periphery.)
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

3. Fig 2
Schematic of in vitro model. The thoracic aorta (B) is suspended with the native aortic valve functioning as the outlet valve. Distally the aorta is connected to rubber tubing (C) with adjustable resistance elements (D). The circulation is driven by a motor piston pump (A). E is a reservoir and F represents the mechanical mitral inlet valve.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

4. Fig 3
Automated edge detection. Shown is an example of echocardiographic continuous automated border detection of the aortic root at baseline (a) and after prosthetic replacement of the ascending aorta (b). Changes in cross-sectional area throughout the cardiac cycle are depicted as curve 1. Note the obvious increase in peak systolic area indicating increased distension of the aortic root after replacement of the ascending aorta. Curve 2 is the aortic root pressure again with a marked elevation of pressure amplitude after wrapping.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

5. Fig 4
Example of pressure patterns at the aortic root in vivo. An increase in the pressure amplitude and a significant increase of the amplitude of the maximum and minimum dicrotic notch pressure without (A) and after (B) graft reinforcement are shown. (AoP = aortic pressure).
The Annals of Thoracic Surgery  , DOI: ( /S (01) )