First results of a regenerative transcatheter heart valve implant from autologous tissue in a long-term animal model. (14th October 2021)

• Record Type: Journal Article
• Authors: Kiekenap, J; Sun, X; Hultsch, J; Dietrich, T; Oetvoes, J; Schmidt, T; Reiter, K; Kargin, H; Emeis, J; Berger, F; Schmitt, B
• Is Part Of: European heart journal. Volume 42(2021)Supplement 1
• Publication Date: 2021-10-14
• Subjects: Pulmonary Valve Intervention; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/eurheartj/ehab724.2229
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Background: The perfect heart valve replacement remains to be found regarding longevity, freedom of anticoagulation and availability in each size. Purpose: Examination of a new technique for a regenerative, immunocompatible, transcatheter pulmonary valve implant from autologous pericardium was performed in an adult sheep model. Methods: For each valve implant a pericardial patch was harvested by left antero-lateral mini-thoracotomy, placed on one of two slightly different shaped moulds either made of acrylic glass (AG) or printed in a 3D Printer (3D) and transferred into a container filled with a biological crosslinking agent at a non-toxic concentration to stabilize the given shape. After a median of 3 days (d) they were unpacked, sewn into a self-expandable nitinol stent with a diameter of 26 or 30mm and implanted via the jugular vein into pulmonary valve position of the same animal using a custom-made delivery system (1). Three groups (Gr) were planned: Gr 1) 4 animals with at least 6 d of crosslinking and AG mould; Gr 2) 5 animals with at least 3 d of crosslinking and AG mould; Gr 3) 6 animals with at least 3 d crosslinking and 3D mould. Follow ups (FU) were performed every 3 months (mo) evaluating valve function by intracardiac echocardiography (ICE) and cardiac MRI for up to 20.5 mo. All experiments were approved and conducted according to German federal law. Results: In 11 of 13 animals minimally-invasive implantation was successful. One animal died because of ventricular fibrillation, in the other the implant dislocated into the right ventricle, so it had to be sacrificed. Direct post-implantation valve insufficiency was evaluated in 9 animals using ICE or angiography. In Gr 1 insufficiency was non-existent (n=2), in Gr 2 moderate or severe (n=2) and in Gr 3 non-existent or mild (n=5). Long term function as shown in figure 1 decreased rapidly in Gr 1 and 2 with median MRI regurgitation fractions (RF) in Gr 1 of 31% at 3 mo (n=3), 41% at 6 mo (n=3), 48% at 9 mo (n=2), 47% at 12 mo (n=3) and in Gr 2 of 43% at 3 and 54% at 6 mo (n=1) after implantation. Median RF in Gr 3 was small with 9% at 3 mo (n=4), 8% at 6 mo (n=3), 8% at 9 mo (n=3), 12% at 13 mo (n=3), 8% at 17 mo (n=2) and 20.5 mo (n=2). We never witnessed valve stenosis in any group at any point in time. Conclusion: Gr 3 showed promising results regarding long time function of the implant which encourages further research with higher validity. The reason for failing of Gr 1 and 2 remains a topic of discussion. Regardless, valuable experience was gained in crafting and conducting the implantation of this new regenerative heart valve implant. Funding Acknowledgement: Type of funding sources: Public grant(s) – National budget only. Main funding source(s): EXIST research transfer program of the federal ministry of education and research