Assessment of Stiffness of Large to Small Arteries in Multistage Renal Disease Model: A Numerical Study

Figures

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  Figure 1. Representation of the complete arterial topology (used in the computer model with the hand and foot topologies, adapted from Reymond et al., 2009). (i) Control with two kidneys configuration (2KDN), kidneys in their usual anatomical location on the aorta. (ii) One kidney configuration (1KDN), the left renal artery (segment 36) is disconnected from the model. (iii) Zero kidneys configuration (0KDN), simulated by removing both the right and the left renal arteries, segments 36 and 38. (iv) Transplanted configuration (TX), both renal arteries were disconnected, the right renal artery (segment 38) was attached into the external iliac artery (segment 44).

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  Figure 2. Pulse transit time (PTT) calculation. The figure shows application of Matlab-based second derivative algorithm using the foot-to-foot method. (A) Carotid pressure signal (top) with its second derivative (bottom), (B) femoral pressure signal (top) with its second derivative (bottom), and (C) digital pressure signal (top) with its second derivative (bottom).

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  Figure 3. Arterial paths as measured in the different methods of the model, by adding up the lengths of the different segments. (A) Carotid-femoral path (Δx_cf) used for the calculation of the cfPWV, measured from the common carotid to the femoral artery via the external iliac. (B) Carotid-radial path (Δx_cr) used for the crPWV calculation, measured from the common carotid to the radial artery via the brachial artery. (C) Radial-digital path (Δx_rd) used for the rdPWV calculation, measured from the radial to the palmar digital artery.

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  Figure 4. Variations of (i) aortic, (ii) carotid, (iii) radial, and (iv) digital blood pressure waveforms in the four kidney configurations (default distensibility and in silico).

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  Figure 5. Variations of the aortic flow waveforms in the four simulated configurations at four different locations in the aorta (default distensibility and in silico).

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  Figure 6. Variations of the carotid, radial, and digital flow waveforms in the four simulated configurations (default distensibility and in silico).

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  Figure 7. Pulse wave velocity (PWV) results obtained with the literature in vivo distensibility data (0KDN) and the model default distensibility data (in silico).

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  Figure 8. Regional arterial stiffness (AS) with varying degrees of distensibility per renal disease status simulation (in silico distensibility).

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  Figure 9. Variations of the aortic pressure and flow waveforms. (A) Pressure waveforms in the non-uniform stiffness configuration without kidneys (0KDN) compared to the default distensibility with 2KDN (control). (B) Flow waveforms in the non-uniform stiffness configuration without kidneys (0KDN) compared to the default distensibility with 2KDN (control).