Optimal Fenestration of the Fontan Circulation

Area of Science:

• Cardiovascular Physiology
• Medical Modeling
• Pediatric Cardiology

Background:

• The Fontan circulation is a complex surgical palliation for single-ventricle congenital heart disease.
• Fenestrations are sometimes added to Fontan physiology to improve hemodynamics but can decrease arterial oxygen saturation.

Purpose of the Study:

• To develop and utilize a pulsatile compartmental model of the Fontan circulation with a fenestration.
• To investigate the hemodynamic effects of fenestration size on oxygen transport and pressures in Fontan patients.
• To identify optimal fenestration parameters for high-risk Fontan physiology.

Main Methods:

• Development of a pulsatile compartmental model incorporating blood flow and oxygen transport.
• Inclusion of fenestration size as a key model parameter.
• Calibration of the model using clinical data from Fontan patients.

Main Results:

• The model simulates the hemodynamic benefits (increased cardiac output, decreased systemic venous pressure) and drawbacks (decreased arterial oxygen saturation) of fenestrations.
• Analysis reveals a range of fenestration sizes where systemic oxygen availability is maintained while systemic venous pressure is reduced in high-risk scenarios.
• Demonstration of the complex interplay between fenestration size and key hemodynamic variables.

Conclusions:

• The pulsatile model provides valuable insights into the functional impact of fenestrations in Fontan circulation.
• Fenestrations can be optimized to balance hemodynamic improvement and oxygen delivery in specific patient populations.
• This modeling approach can aid in understanding and managing Fontan patient physiology.