Tailoring the hybrid palliation for hypoplastic left heart syndrome: A simulation study using a lumped parameter...

Area of Science:

• Cardiovascular Physiology
• Medical Engineering
• Pediatric Cardiology

Background:

• Hypoplastic left heart syndrome (HLHS) requires complex surgical interventions like the hybrid procedure (HP).
• HP outcomes are influenced by pulmonary artery banding (PAB), atrial septal defect (ASD), and patent ductus arteriosus (PDA) stent size.
• Aortic coarctation (CoAo) is a potential complication of HP, with reverse Blalock-Taussig shunt (RevBT) proposed as a mitigation strategy.

Purpose of the Study:

• To develop a lumped parameter model (LPM) for investigating the hemodynamic effects of key variables in the HP for HLHS.
• To assess the influence of ASD size, PAB tightness, PDA stent size, and RevBT diameter on HP hemodynamics.
• To evaluate the potential of RevBT to negate CoAo effects within the HP context.

Main Methods:

• Development of a lumped parameter model (LPM) to simulate HP hemodynamics in HLHS.
• Model calibration and preliminary verification using patient-specific data from a newborn HLHS patient.
• Simulation of various PAB, ASD, PDA, and RevBT configurations to analyze their hemodynamic impact.

Main Results:

• Hemodynamics are significantly affected by ASD size (influencing Qp/Qs, CO, SW) and PAB diameter (also impacting Qp/Qs, CO, SW).
• RevBT diameter and PDA diameter greater than 0.2 cm did not show a significant impact on overall hemodynamics.
• RevBT implantation did not alter HP hemodynamics but was found to potentially make CoAo effects negligible.

Conclusions:

• LPM is a valuable tool for understanding and supporting clinical decisions in complex pediatric cardiovascular physiopathology.
• ASD and PAB are critical parameters requiring precise calibration for optimizing HP outcomes in HLHS.
• RevBT may serve as a protective measure against CoAo complications without adversely affecting HP hemodynamics.