Atrial cardiomyoplasty after Fontan-type procedures.

Area of Science:

• Cardiac Surgery
• Cardiovascular Research
• Biomedical Engineering

Background:

• Fontan-type procedures are complex surgeries for single-ventricle defects, often facing challenges with atrial-pulmonary flow.
• Current methods require improved strategies to manage hemodynamics and enhance outcomes post-Fontan procedure.

Purpose of the Study:

• To evaluate the efficacy of right atrial cardiomyoplasty using a stimulated latissimus dorsi muscle flap (LDMF) to augment atrial-pulmonary flow.
• To assess the potential of creating a functional 'ventricle' from the right atrium in a Fontan-like model.

Main Methods:

• Developed two surgical techniques in 10 goats to bypass the right ventricle and perform right atrial cardiomyoplasty with an LDMF.
• Group 1: Direct connection of right atrial appendages to the pulmonary artery. Group 2: Implantation of caval valves and closure of the tricuspid orifice before atriopulmonary connection.
• Stimulated the LDMF over the right atrium using a Cardiomyostimulator and performed acute hemodynamic assessments, including pressure and cardiac output measurements.

Main Results:

• LDMF stimulation successfully restored pulsatile pressure patterns in the pulmonary artery.
• Cardiac output was significantly increased following LDMF stimulation, with more pronounced effects in the model with caval valve implantation.
• The functional 'ventricularization' of the right atrium demonstrated positive acute hemodynamic effects.

Conclusions:

• Right atrial cardiomyoplasty with a stimulated LDMF can improve hemodynamics in a Fontan-like model.
• This technique shows potential to enhance long-term results and broaden operative indications for Fontan-type procedures.
• Further chronic studies are required to fully assess the diastolic and systolic functions of the neo-right ventricle.