Computational fluid dynamic and magnetic resonance analyses of flow distribution between the lungs after total cavopulmonary connection

1999 ◽  
Vol 46 (4) ◽  
pp. 393-399 ◽  
Author(s):  
F. Migliavacca ◽  
P.J. Kilner ◽  
G. Pennati ◽  
G. Dubini ◽  
R. Pietrabissa ◽  
...  
1999 ◽  
Vol 14 (3) ◽  
pp. 154-160 ◽  
Author(s):  
Masao Tayama ◽  
Nobuaki Hirata ◽  
Tohru Matsushita ◽  
Tetsuya Sano ◽  
Norihide Fukushima ◽  
...  

2004 ◽  
Vol 126 (6) ◽  
pp. 709-713 ◽  
Author(s):  
J. C. Masters ◽  
M. Ketner ◽  
M. S. Bleiweis ◽  
M. Mill ◽  
A. Yoganathan ◽  
...  

Background—The total cavopulmonary connection (TCPC), a palliative correction for congenital defects of the right heart, is based on the corrective technique developed by Fontan and Baudet. Research into the TCPC has primarily focused on reducing power loss through the connection as a means to improve patient longevity and quality of life. The goal of our study is to investigate the efficacy of including a caval offset on the hemodynamics and, ultimately, power loss of a connection. As well, we will quantify the effect of vessel wall compliance on these factors and, in addition, the distribution of hepatic blood to the lungs. Methods—We employed a computational fluid dynamic model of blood flow in the TCPC that includes both the non-Newtonian shear thinning characteristics of blood and the nonlinear compliance of vessel tissue. Results—Power loss in the rigid-walled simulations decayed exponentially as caval offset increased. The compliant-walled results, however, showed that after an initial substantial decrease in power loss for offsets up to half the caval diameter, power loss increased slightly again. We also found only minimal mixing in both simulations of all offset models. Conclusions—The increase in power loss beyond an offset of half the caval diameter was due to an increase in the kinetic contribution. Reduced caval flow mixing, on the other hand, was due to the formation of a pressure head in the offset region which acts as a barrier to flow.


2006 ◽  
Vol 18 (10) ◽  
pp. 787-794 ◽  
Author(s):  
Kevin R. Minard ◽  
Daniel R. Einstein ◽  
Richard E. Jacob ◽  
Senthil Kabilan ◽  
Andrew P. Kuprat ◽  
...  

2008 ◽  
Vol 295 (6) ◽  
pp. H2427-H2435 ◽  
Author(s):  
Kartik S. Sundareswaran ◽  
Kerem Pekkan ◽  
Lakshmi P. Dasi ◽  
Kevin Whitehead ◽  
Shiva Sharma ◽  
...  

Little is known about the impact of the total cavopulmonary connection (TCPC) on resting and exercise hemodynamics in a single ventricle (SV) circulation. The aim of this study was to elucidate this mechanism using a lumped parameter model of the SV circulation. Pulmonary vascular resistance (1.96 ± 0.80 WU) and systemic vascular resistances (18.4 ± 7.2 WU) were obtained from catheterization data on 40 patients with a TCPC. TCPC resistances (0.39 ± 0.26 WU) were established using computational fluid dynamic simulations conducted on anatomically accurate three-dimensional models reconstructed from MRI ( n = 16). These parameters were used in a lumped parameter model of the SV circulation to investigate the impact of TCPC resistance on SV hemodynamics under resting and exercise conditions. A biventricular model was used for comparison. For a biventricular circulation, the cardiac output (CO) dependence on TCPC resistance was negligible (sensitivity = −0.064 l·min−1·WU−1) but not for the SV circulation (sensitivity = −0.88 l·min−1·WU−1). The capacity to increase CO with heart rate was also severely reduced for the SV. At a simulated heart rate of 150 beats/min, the SV patient with the highest resistance (1.08 WU) had a significantly lower increase in CO (20.5%) compared with the SV patient with the lowest resistance (50%) and normal circulation (119%). This was due to the increased afterload (+35%) and decreased preload (−12%) associated with the SV circulation. In conclusion, TCPC resistance has a significant impact on resting hemodynamics and the exercise capacity of patients with a SV physiology.


1999 ◽  
Vol 42 (6) ◽  
pp. 34-39 ◽  
Author(s):  
Ting-Kwo Lei ◽  
Andrew Manning ◽  
Felix Kersting

Acommercial Computational Fluid Dynamic (CFD) software program was used to analyze the flow field inside a cleanroom ceiling plenum. The design required restricted space for the HVAC equipment. The effect of the number of cells used in the computational model on the simulation output was investigated. Pressure and velocity fields were examined. A comparison of flow distribution uniformity between a reference ceiling plenum system and a ceiling plenum system containing more ducted air supplies was made. An analysis of the effect of diffusion plates was conducted.


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