Related Experiment Video
Updated: May 27, 2026
Transcatheter Pulmonary Valve Replacement from Autologous Pericardium with a Self-Expandable Nitinol Stent in an Adult Sheep Model
Published on: June 8, 2022
Transcatheter implantation of self-expandable valved prosthesis in outlet right ventricle an experimental study in
José Cícero Stocco Guilhen1, José Honório Palma, Diego Felipe Gaia
1Universidade Federal de São Paulo Escola Paulista de Medicina, São Paulo, Brasil. guilhenzezo@hotmail.com
Insights
This study explored a new less invasive method for implanting a pulmonary valve prosthesis in pigs, finding it feasible but noting thrombus formation as a complication needing further research.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Interventional Cardiology
Background:
- Congenital heart disease patients undergoing pulmonary valve surgery often face residual issues like pulmonary insufficiency or stenosis.
- These complications can lead to right heart failure, necessitating lifelong interventions and increasing morbidity/mortality.
Purpose of the Study:
- To develop and evaluate a less invasive technique for implanting a valved prosthesis via the right ventricle.
- To assess the feasibility of a novel, minimally invasive approach for pulmonary valve replacement.
Main Methods:
- A valved prosthesis was designed using a nitinol stent with bovine pericardium leaflets.
- Implants were performed in twelve pigs, with echocardiographic monitoring at multiple time points post-procedure.
Main Results:
- Mild to severe reflux was observed in some animals; transvalvular gradients initially increased but decreased over time.
- Four out of twelve animals had gradients above 20 mmHg post-implantation.
- Prosthesis thrombus formation was the most frequent complication, occurring in six animals.
Conclusions:
- The study demonstrates the potential for minimally invasive pulmonary valve implantation.
- Further research is needed, particularly investigating anticoagulant and antiplatelet therapies to mitigate thrombus formation.
- This approach could advance the use of prosthetic heart valves implanted without cardiopulmonary bypass.
Introduction:
Patients with congenital heart disease who underwent pulmonary valvotomy or surgery to open the pulmonary valve ring are prone to develop residual pulmonary insufficiency or stenosis that may lead to right heart failure with clinical deterioration. These children require multiple interventions throughout their lives, which impose a high rate of morbidity and mortality.
Objective:
To develop a less invasive technique for implantation of a valved prosthesis through the right ventricle.
Methods:
The valved prosthesis consists of an auto expanding metal stent built with nitinol, surrounded with polyester, where the three leaflets of bovine pericardium were mounted. Twelve pigs were used to perform the implants. Echocardiographic control was performed immediately after implantation and one, four, eight and 12 weeks.
Results:
One animal showed reflux of moderate to severe and three mild reflux. Transvalvular gradients measured before implantation ranged from 3 to 6 mmHg and that soon after the implant was increased, ranging from 7 to 45 mmHg. There was a decrease in these gradients during follow up and in only four of the twelve animals the gradients were above 20 mmHg. Thrombus formation occurred in the prosthesis of six animals, and this was the most frequent complication.
Conclusion:
These findings highlight the need for studies with the use of anticoagulants and antiplatelet, an attempt to reduce this event. The study aims to contribute for the start of the use of prosthetic heart valves that could be implanted through minimally invasive techniques without the use of cardiopulmonary bypass.
