Splitting the anterior mitral leaflet impairs left ventricular function in an ovine model

Area of Science:

• Cardiovascular Surgery
• Cardiac Physiology
• Surgical Techniques

Background:

• Mitral valve replacement often involves anterior mitral leaflet resection or modification.
• Anterior leaflet splitting is a less disruptive approach.
• Reattaching the modified leaflet to the annulus shortens the annulopapillary distance.

Purpose of the Study:

• To quantify the acute effects of anterior mitral leaflet splitting and annulopapillary distance shortening on left ventricular function.
• To assess the impact of these modifications in an ovine model.

Main Methods:

• Six adult sheep underwent anterior leaflet splitting and annulopapillary distance reduction using exteriorized wires and snares.
• A mechanical mitral prosthesis was used to ensure valve competence during manipulations.
• Left ventricular function was measured before and after each intervention.

Main Results:

• Anterior leaflet splitting significantly decreased stroke volume, cardiac output, and left ventricular pressures.
• Shortening the annulopapillary distance led to substantial reductions in contractility and systolic function.
• Combined interventions did not result in further significant impairment.

Conclusions:

• Anterior mitral leaflet splitting acutely impairs left ventricular contractility and hemodynamics.
• Shortening the annulopapillary distance post-leaflet splitting does not exacerbate the functional decline.