Background: The Xeltis biorestorative transcatheter heart valve (BTHV) leaflets are made from an eletrospun bioabsorbable supramolecular polycarbonate-urethane and are mounted on a self-expanding nitinol frame. Acute hemodynamic performance of this BTHV was favorable.
Aims: We sought to demonstrate preclinical feasibility of a novel BTHV by evaluating the hemodynamic performances of 5 pilot valve designs up to 12 months in a chronic ovine model.
Methods: Five design iterations (A, B, B’, C, and D) of the BTHV were transapically implanted in 46 sheep; chronic data were available in 39 animals. Assessments were performed at implantation, 3-, 6-, and 12-months including quantitative aortography, echocardiography, and histology.
Results: At 12-months, greater than or equal to moderate AR on echocardiography was seen in 0%, 100%, 33.3%, 100%, and 0% in the iterations A, B, B’, C, and D, respectively. Furthermore, transprosthetic mean gradients on echocardiography was 10.0±2.8mmHg, 19.0±1.0mmHg, 8.0±1.7mmHg, 26.8±2.4mmHg, and 11.2±4.1mmHg, and effective orifice area was 0.7±0.3cm2, 1.1±0.3cm2, 1.5±1.0cm2, 1.5±0.6cm2, and 1.0±0.4cm2 in the iterations A, B, B’, C, and D, respectively. On pathological evaluation, the iteration D demonstrated generally intact leaflets and advanced tissue coverage, while different degrees of structural deterioration were observed in the other design iterations.
Conclusions: Several leaflet material iterations were compared for potential to demonstrate endogenous tissue restoration in an aortic valve in-vivo. The most promising iteration showed intact leaflets and acceptable hemodynamic performance at 12 months, illustrating the potential of BTHV.