Optimal fenestration of the Fontan circulation

TL;DR

This paper presents a pulsatile model of the Fontan circulation to analyze the effects of fenestration, identifying an optimal size that balances hemodynamic benefits and oxygen saturation in high-risk patients.

Contribution

It introduces a new model incorporating fenestration size and blood oxygen transport, calibrated with clinical data, to optimize fenestration design in Fontan patients.

Findings

Optimal fenestration size maximizes oxygen delivery in high-risk scenarios.

Fenestration improves cardiac output and reduces venous pressure.

Trade-offs between oxygen saturation and hemodynamics are quantified.

Abstract

In this paper, we develop a pulsatile compartmental model of the Fontan circulation and use it to explore the effects of a fenestration added to this physiology. A fenestration is a shunt between the systemic and pulmonary veins that is added either at the time of Fontan conversion or at a later time for the treatment of complications. This shunt increases cardiac output and decreases systemic venous pressure. However, these hemodynamic benefits are achieved at the expense of a decrease in the arterial oxygen saturation. The model developed this paper incorporates fenestration size as a parameter and describes both blood flow and oxygen transport. It is calibrated to clinical data from Fontan patients, and we use it to study the impact of a fenestration on several hemodynamic variables. In certain scenarios corresponding to high-risk Fontan physiology, we demonstrate the existence of an optimal fenestration size that maximizes oxygen delivery to the systemic tissues.