Comparative computational fluid dynamic study of two distal Contegra conduit anastomoses

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Cardiovascular Surgery

Background:

• Distal anastomosis in pulmonary artery (PA) reconstructions is crucial for surgical outcomes.
• Conventional circular anastomosis can lead to suboptimal hemodynamics and stenosis.
• Alternative configurations are needed to improve blood flow and reduce complications.

Purpose of the Study:

• To compare the hemodynamic performance of circular versus elliptical distal anastomosis configurations for 12 mm Contegra conduits.
• To evaluate pressure, velocity, and shear stress distributions in the PA from origin to bifurcation.
• To determine if elliptical anastomosis offers advantages over circular anastomosis in reducing stenosis risk.

Main Methods:

• Computational Fluid Dynamics (CFD) simulations were employed.
• Two anastomosis configurations (circular and elliptical) were modeled.
• Hemodynamic parameters including pressure, velocity, and shear stress were analyzed.

Main Results:

• Elliptical anastomosis provided a 54% larger cross-sectional area than circular.
• Circular anastomosis showed significant flow stagnation and peak pressure at the PA bifurcation.
• Elliptical anastomosis demonstrated more homogeneous pressure, velocity, and shear stress, with preferential flow in the left PA.

Conclusions:

• Elliptical anastomosis results in more favorable hemodynamic profiles compared to circular anastomosis at the PA bifurcation.
• The increased cross-sectional area and improved flow distribution of elliptical anastomosis may reduce distal stenosis incidence.
• Elliptical anastomosis is a promising alternative for PA reconstructions, especially with small conduits.