Many congenital heart defects and degenerative valve diseases require replacement\nof heart valves in children and young adults. Transcatheter xenografts degenerate over time.\nTissue engineering might help to overcome this limitation by providing valves with ability for\nself-repair. A transcatheter decellularized tissue-engineered heart valve (dTEHV) was developed\nusing a polyglycolic acid (PGA) scaffold. A first prototype showed progressive regurgitation after\n6 months in-vivo due to a suboptimal design and misguided remodeling process. A new geometry\nwas developed accordingly with computational fluid dynamics (CFD) simulations and implemented\nby adding a polyether-ether-ketone (PEEK) insert to the bioreactor during cultivation. This lead to\nmore belly-shaped leaflets with higher coaptation areas for this second generation dTEHV. Valve\nfunctionality assessed via angiography, intracardiac echocardiography, and MRI proved to be much\nbetter when compared the first generation dTEHV, with preserved functionality up to 52 weeks after\nimplantation. Macroscopic findings showed no thrombi or signs of acute inflammation. For the\nsecond generation dTEHV, belly-shaped leaflets with soft and agile tissue-formation were seen after\nexplantation. No excessive leaflet shortening occurred in the second generation dTEHV. Histological\nanalysis showed complete engraftment of the dTEHV, with endothelialization of the leaflets and\nthe graft wall. Leaflets consisted of collagenous tissue and some elastic fibers. Adaptive leaflet\nremodeling was visible in all implanted second generation dTEHV, and most importantly no fusion\nbetween leaflet and wall was found. Very few remnants of the PGA scaffold were detected even\n52 weeks after implantation, with no influence on functionality. By adding a polyether-ether-ketone\n(PEEK) insert to the bioreactor construct, a new geometry of PGA-scaffold based dTEHV could be\nimplemented. This resulted in very good valve function of the implanted dTEHV over a period of\n52 weeks.
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