Aortic flow after valve sparing root replacement with or without neosinuses reconstruction

Area of Science:

• Cardiovascular Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Valve-sparing root replacement is a complex procedure for aortic root aneurysms.
• The impact of aortic root reconstruction techniques on hemodynamics is not fully understood.
• Accurate assessment of aortic flow dynamics is crucial for evaluating surgical outcomes.

Purpose of the Study:

• To compare aortic flow dynamics after valve-sparing root replacement using prostheses with and without Valsalva sinus reconstruction.
• To assess differences in rotational flow and wall shear stress between surgical techniques.
• To evaluate the occurrence of abnormal wall shear stress in the descending aorta.

Main Methods:

• Utilized 4-dimensional flow magnetic resonance imaging (4D Flow MRI) on 3.0T MRI units.
• Enrolled patients undergoing valve-sparing root replacement (n=20) and healthy controls (n=10).
• Processed 4D Flow MRI data to analyze flow streamlines, rotational flow, and wall shear stress (WSS).

Main Results:

• Prostheses with neosinuses demonstrated physiologic sinus vortices, unlike straight grafts.
• Recreating sinuses significantly reduced velocity and WSS in the ascending aorta compared to straight grafts and controls.
• Abnormal WSS incidence was substantially higher in straight tube grafts than in neosinus grafts.

Conclusions:

• Reconstruction of the sinuses of Valsalva during valve-sparing root replacement promotes more physiologic flow.
• This technique is associated with significantly lower wall shear stress in the aortic root.
• Observed lower WSS in the distal thoracic aorta suggests potential benefits for aortic remodeling.