The convergent cavopulmonary connection: A novel and efficient configuration of Fontan to accommodate mechanical support

Pranava Sinha; Jacqueline Contento; Byeol Kim; Kevin Wang; Qiyuan Wu; Vincent Cleveland; Paige Mass; Yue-Hin Loke; Axel Krieger; Laura Olivieri

doi:10.1016/j.xjon.2022.12.009

The convergent cavopulmonary connection: A novel and efficient configuration of Fontan to accommodate mechanical support

JTCVS Open. 2023 Jan 11:13:320-329. doi: 10.1016/j.xjon.2022.12.009. eCollection 2023 Mar.

Authors

Pranava Sinha¹, Jacqueline Contento², Byeol Kim³, Kevin Wang⁴, Qiyuan Wu³, Vincent Cleveland², Paige Mass², Yue-Hin Loke^{2

5}, Axel Krieger³, Laura Olivieri^{2

6}

Affiliations

¹ Department of Pediatric Cardiac Surgery, M Health Fairview, University of Minnesota, Minneapolis, Minn.
² Sheikh Zayed Institute of Pediatric Surgical Innovation, Children's National Hospital, Washington, DC.
³ Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Md.
⁴ Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Md.
⁵ Division of Cardiology, Children's National Hospital, Washington, DC.
⁶ Division of Pediatric Cardiology, University of Pittsburgh Medical Center, Pittsburgh, Pa.

Abstract

Objective: The current total cavopulmonary connection Fontan has competing inflows and outflows, creating hemodynamic inefficiencies that contribute to Fontan failure and complicate placement and efficiency of mechanical circulatory support. We propose a novel convergent cavopulmonary connection (CCPC) Fontan design to create a single, converged venous outflow to the pulmonary arteries, thus increasing efficiency and mechanical circulatory support access. We then evaluate the feasibility and hemodynamic performance of the CCPC in various patient sizes using computational fluid dynamic assessments of computer-aided designs.

Methods: Cardiac magnetic resonance imaging data from 12 patients with single ventricle (10 total cavopulmonary connection, 2 Glenn) physiology (body surface area, 0.5-2.0 m²) were segmented to create 3-dimensional replicas of all thoracic structures. Surgically feasible CCPC shapes within constraints of anatomy were created using iterative computational fluid dynamic and clinician input. Designs varied based on superior and inferior vena cava conduit sizes, coronal attachment height, coronal entry angle, and axial entry angle of the superior vena cava to the inferior vena cava. CCPC designs were optimized based on efficiency (indexed power loss), risk of arteriovenous malformations (hepatic flow distribution), and risk of flow stasis (% nonphysiologic wall shear stress).

Results: All CCPC designs met hemodynamic performance thresholds for indexed power loss and hepatic flow distribution. CCPC designs showed improvements in reducing % nonphysiologic wall shear stress and balancing HFD.

Conclusions: CCPC is physiologically and surgically feasible in various patient sizes using validated computational fluid dynamic models. CCPC configuration has analogous indexed power loss, hepatic flow distribution, and % nonphysiologic wall shear stress compared with total cavopulmonary connection, and the single inflow and outflow may ease mechanical circulatory support therapies. Further studies are required for design optimization and mechanical circulatory support institution.

Keywords: Fontan redesign; computational fluid dynamics; hepatic flow distribution; indexed power loss; mechanical circulatory support; wall shear stress.