Right ventricular outflow tract reconstructive model in adult sheep

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Animal Models

Background:

• Congenital right ventricular outflow tract lesions necessitate invasive procedures, often requiring multiple surgeries with associated risks.
• Less invasive approaches are needed to improve patient outcomes and reduce morbidity and mortality.
• Percutaneous transcatheter valve placement shows promise, but requires robust preclinical evaluation.

Purpose of the Study:

• To develop and validate an adult sheep model for the preclinical evaluation of percutaneous transcatheter pulmonary valve (TPV) implantation.
• To assess the long-term safety and efficacy of TPVs in a physiologically relevant model.
• To refine preoperative, surgical, and postoperative techniques for TPV implantation studies.

Main Methods:

• Adult sheep underwent surgical implantation of a valve conduit in the right ventricular outflow tract.
• Test animals received an additional Melody transcatheter pulmonary valve (TPV) within the conduit; control animals received only the conduit.
• Preoperative, surgical, and postoperative protocols were established for long-term evaluation over 5 months.

Main Results:

• Fifteen sheep survived the surgical procedure; 11 of these survived to the 5-month termination point.
• Early postoperative mortality occurred in 4 animals (3 infection, 1 heart failure).
• The model allowed for accurate physiological assessment of the implanted TPV over the study duration.

Conclusions:

• The developed adult sheep model is effective for the long-term preclinical assessment of percutaneous TPV implantation for right ventricular outflow tract lesions.
• The model facilitates evaluation of TPV safety and efficacy using established surgical and postoperative techniques.
• This preclinical approach supports the advancement of less invasive treatments for congenital heart defects.