Computational fluid dynamic study of flow optimization in realistic models of the total cavopulmonary connections.
OBJECTIVE
In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The influence of various inferior vena cava to pulmonary artery connections in this unique circulatory arrangement was evaluated using computation fluid dynamics methods.


METHODS
Realistic three-dimensional models of total cavopulmonary connections were created from angiographic measurements to include the hepatic vein, superior vena cava, and branches of the pulmonary arteries. Steady-state finite volume analyses were performed using identical in vivo boundary conditions. Computational solutions calculated the percent hydraulic power dissipation and left-to-right pulmonary arterial flow distribution.


RESULTS
Simulations of the lateral tunnel, intra-atrial tube, extracardiac conduit with left and right pulmonary artery anastomosis demonstrated extracardiac conduit with left pulmonary artery anastomosis having the lowest energy loss. Varying the extracardiac conduit from 10 to 30 mm resulted in the least energy dissipation at 20 mm. Serial dilation of the lateral tunnel pathway showed a small incremental worsening of energy loss.


CONCLUSIONS
Maximizing energy conservation in a low-energy flow domain, such as the Fontan circulation, can be significant to its fluid dynamic performance. Although computational modeling cannot predict postoperative failure or functional outcome, this study confirms the importance of local geometry of the surgically created pathway in the total cavopulmonary connection.
Hsia
Tain-Yen
TY
Bioengineering and Structural Engineering Department, Politecnico di Milano, Milan, Italy. hsia@jhmi.edu
Migliavacca
Francesco
F
Pittaccio
Simone
S
Radaelli
Alessandro
A
Dubini
Gabriele
G
Pennati
Giancarlo
G
de Leval
Marc
M
D001807:Blood Vessel Prosthesis; D002648:Child; D003198:Computer Simulation; D004867:Equipment Design; D018729:Fontan Procedure; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000503:physiopathology*; D012039:Regional Blood Flow; D014684:Venae Cavae / Q000503:physiopathology*