Target Flow-Pressure Operating Range for Designing a Failing Fontan Cavopulmonary Support Device

Engineering Perspective on Cardiovascular Simulations of Fontan Hemodynamics: Where Do We Stand with a Look Towards Clinical Application

BACKGROUND

Cardiovascular simulations for patients with single ventricles undergoing the Fontan procedure can assess patient-specific hemodynamics, explore surgical advances, and develop personalized strategies for surgery and patient care. These simulations have not yet been broadly accepted as a routine clinical tool owing to a number of limitations. Numerous approaches have been explored to seek innovative solutions for improving methodologies and eliminating these limitations.

PURPOSE

This article first reviews the current state of cardiovascular simulations of Fontan hemodynamics. Then, it will discuss the technical progress of Fontan simulations with the emphasis of its clinical impact, noting that substantial improvements have been made in the considerations of patient-specific anatomy, flow, and blood rheology. The article concludes with insights into potential future directions involving clinical validation, uncertainty quantification, and computational efficiency. The advancements in these aspects could promote the clinical usage of Fontan simulations, facilitating its integration into routine clinical practice.

Mechanical Support of the Failing Fontan Circulation

The Fontan is the final common pathway for most single ventricle lesions. It is not a durable circulation and many Fontan patients eventually present for advanced heart failure therapies including mechanical circulatory support. While there have been advancements in available durable devices, many pediatric patients have size, anatomical, and physiologic constraints that make placement of adult ventricular assist devices challenging. And, Fontan failure comes in different varieties, including failure with preserved systolic function. This subset of patients requires either a subpulmonary assist device or a total artificial heart. Unique operative maneuvers, including atrial cannulation and atrioventricular valve manipulation have allowed many failing Fontan patients to be bridged to transplant after recovery of end-organ dysfunction and improved nutrition. The Advanced Cardiac Therapies Improving Outcomes Network is a multicenter learning network of pediatric hospitals implanting, managing, and studying ventricular assist devices in children and adults with congenital heart disease. This network is advancing the knowledge of outcomes and approaches to mechanical circulatory support in those with congenital heart disease, including Fontans. The congenital heart disease community continues to work toward and hope for a smaller durable device that will help this complex cohort of patients.