Mechanical Circulatory Support for the Failing Fontan: Conversion to Assisted Single Ventricle...

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Pediatric Cardiology

Background:

• Failing Fontan circulation presents significant challenges for mechanical circulatory support (MCS).
• A novel approach involving conversion to a mechanically assisted single ventricle parallel circulation (MASVC) was investigated.

Purpose of the Study:

• To evaluate the feasibility and hemodynamic performance of MASVC in a porcine model of single ventricle physiology.
• To assess the potential of MASVC as a form of MCS for Fontan circulation.

Main Methods:

• A porcine model of univentricular circulation was created surgically.
• A centrifugal flow pump was integrated to create the MASVC, connecting the common atrium to the aorta and pulmonary artery.
• Hemodynamic parameters, including systemic (Qs) and pulmonary (Qp) blood flow, were measured, and the Qp/Qs ratio was regulated.

Main Results:

• Successful weaning from cardiopulmonary bypass (CPB) to MASVC was achieved in all four animals for two hours.
• MASVC demonstrated satisfactory hemodynamics, though with lower arterial oxygen saturation and partial pressure of oxygen compared to baseline.
• A trend towards decreased mixed venous saturation and increased serum lactate levels was observed during support.

Conclusions:

• Mechanically assisted single ventricle parallel circulation (MASVC) is achievable in a single ventricle animal model.
• This strategy shows potential for providing mechanical circulatory support (MCS) in single ventricle circulations.
• Longer-term studies are necessary to determine the adequacy and sustainability of MASVC.