Postsurgical Comparison of Pulsatile Hemodynamics in Five Unique Total Cavopulmonary Connections: Identifying Ideal Connection Strategies

Abstract

Appropriate choice of Fontan pathway requires keen preoperative examination of angiographic anatomy. We hypothesize that surgical choices may be better informed by lessons learned from postoperative hemodynamic evaluation in different Fontan connection strategies. High-performance computational fluid dynamics is employed to evaluate hemodynamics in five unique Fontan anatomies. Our cohort included one lateral tunnel, extracardiac conduit, intraatrial conduit, intra/extracardiac conduit, and direct cavopulmonary connection (DCPC) Fontan pathway. Theoretical cardiac cycle-averaged power loss (Eloss) and hepatic flow distribution (HFD) were compared after modeling identical physiologic pulsatile caval flow and time-resolved pulmonary artery flow distribution. The Eloss was also evaluated at instants of peak inferior vena cava flow and peak superior vena cava flow to study caval anastomosis shape sensitivity on hemodynamics. Quantitative examination of Eloss and HFD revealed minimum cycle-averaged Eloss in the extracardiac conduit Fontan; however, at the cost of the poorest HFD (left pulmonary artery/right pulmonary artery= 84.5%/15.5%). In contrast, DCPC Fontan was found to have the best trade-off between mean Eloss (5.87 mW, 2.44%) and HFD (left pulmonary artery/right pulmonary artery= 38.9%/61.1%). Except for intraatrial conduit, the instantaneous superior vena cava and inferior vena cava peak flow Eloss exceeded the cycle average Eloss. The peak inferior vena cava flow Eloss of DCPC Fontan nearly equaled its cycle-averaged Eloss (∼5.69 mW). Considering cycle-averaged Eloss, HFD, and peak inferior vena cava flow Eloss, DCPC had the best hemodynamic performance. Intraatrial conduit Fontan is an efficient modification of lateral tunnel Fontan that offers possibility for excellent streamlining of inferior vena cava and superior vena cava with the pulmonary arteries.