OBJECTIVES: Transfemoral application of pulmonary heart valves has been studied for the past 10 years. Nevertheless, size restriction of percutaneous heart valved stents is still imminent. METHODS: In this study we implanted percutaneously a novel, low-profile polyurethane valved stent. Percutaneous implantation in pulmonary position was evaluated in 7 sheep. The new valved stent fits into a 14F delivery device. The self-expanding nitinol stent was produced by using a dip-coating technique, and a modified commercially available endovascular stent graft system served as a delivery device. The valved stents were deployed directly over the native pulmonary valve under fluoroscopic control. Transthoracic echocardiography was performed after 4 weeks. At the time of explantation, the animals were reanalyzed and killed. Angiography was performed at implantation and at the end of the study. Explanted constructs were analyzed macroscopically and microscopically. RESULTS: Angiography and echocardiography in all animals demonstrated orthotopic position of the stents at the time of implantation and after 4 weeks. During the deployment procedure, rhythm disturbances occurred in all animals. The peak-to-peak transvalvular gradient was 2.3 +/- 1.2 mm Hg initially and 4.1 +/- 2.4 mm Hg at follow-up. One-month follow-up confirmed competent neovalves without any paravalvular leakage. Gross morphology demonstrated good opening and closure characteristics. No calcification was seen macroscopically, and surrounding tissue was free of calcification. CONCLUSION: In the present study we demonstrated successful merging of 2 novel technologies for percutaneous treatment of pulmonary valve diseases using polyurethane stent valve constructs. Copyright 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
OBJECTIVES: Transfemoral application of pulmonary heart valves has been studied for the past 10 years. Nevertheless, size restriction of percutaneous heart valved stents is still imminent. METHODS: In this study we implanted percutaneously a novel, low-profile polyurethane valved stent. Percutaneous implantation in pulmonary position was evaluated in 7 sheep. The new valved stent fits into a 14F delivery device. The self-expanding nitinol stent was produced by using a dip-coating technique, and a modified commercially available endovascular stent graft system served as a delivery device. The valved stents were deployed directly over the native pulmonary valve under fluoroscopic control. Transthoracic echocardiography was performed after 4 weeks. At the time of explantation, the animals were reanalyzed and killed. Angiography was performed at implantation and at the end of the study. Explanted constructs were analyzed macroscopically and microscopically. RESULTS: Angiography and echocardiography in all animals demonstrated orthotopic position of the stents at the time of implantation and after 4 weeks. During the deployment procedure, rhythm disturbances occurred in all animals. The peak-to-peak transvalvular gradient was 2.3 +/- 1.2 mm Hg initially and 4.1 +/- 2.4 mm Hg at follow-up. One-month follow-up confirmed competent neovalves without any paravalvular leakage. Gross morphology demonstrated good opening and closure characteristics. No calcification was seen macroscopically, and surrounding tissue was free of calcification. CONCLUSION: In the present study we demonstrated successful merging of 2 novel technologies for percutaneous treatment of pulmonary valve diseases using polyurethane stent valve constructs. Copyright 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
Authors: Richard L Li; Jonathan Russ; Costas Paschalides; Giovanni Ferrari; Haim Waisman; Jeffrey W Kysar; David Kalfa Journal: Biomaterials Date: 2019-09-17 Impact factor: 12.479