Valved stents for transapical pulmonary valve replacement

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering

Background:

• Pulmonary valve insufficiency is a major cause of reoperations in congenital cardiac surgery.
• Current percutaneous pulmonary valve replacement has limitations due to access vessel size and right ventricular outflow tract variability.

Purpose of the Study:

• To assess the feasibility of transapical pulmonary valve replacement using a new valved stent design.
• To evaluate the safety and efficacy of this novel approach in a preclinical model.

Main Methods:

• A new valved stent was implanted off-pump into the native right ventricular outflow tract of 8 pigs via the right ventricular apex.
• Continuous intracardiac echocardiographic and fluoroscopic guidance was used.
• Device function was assessed using invasive and noninvasive measures.

Main Results:

• 100% procedural success was achieved with a procedural time of 75 ± 15 minutes.
• All devices demonstrated good acute valve function without dislodgement, significant regurgitation, or paravalvular leaking.
• No right ventricular dysfunction or damage to the pulmonary artery was observed; planimetric valve orifice was 2.85 ± 0.32 cm(2).

Conclusions:

• The transapical approach for pulmonary valve replacement is feasible and safe.
• The novel valved stent design is valid and may be applicable to a broader patient population, including pediatric and adult patients with native right ventricular outflow tracts.