From the Cardiac Surgery, Cardiocentro Ticino, Lugano, Switzerland.
Cardiovascular Research Unit, University Hospital of Lausanne, Lausanne, Switzerland.
ASAIO J. 2019 Nov/Dec;65(8):874-881. doi: 10.1097/MAT.0000000000000903.
Transcatheter aortic root repair (TARR) is still not available because of the complex anatomy. In order to develop future TARR technologies, a human-derived bench test model is required before performing animal tests. For this purpose, we aimed to validate computed tomography (CT)-derived 3D-printed root models for TARR technologies. Four human CT-derived roots were printed using different resins: Visijet M3 Crystal, Photopolymer gel SUP705, Formlabs flexible resin, and Materialise HeartPrint Flex. A stress test was performed using a 26-mm balloon-expandable Sapien valve deployed in aortic position. The too rigid Visijet M3 Crystal was not tested. Among the others, all but one (HeartPrint Flex, Materialise, Leuven, Belgium) ruptured during the test showing low wall resistances. Further tests were then performed in two roots made of HeartPrint Flex resin. The anatomic validation was performed comparing human CT scan-derived 3D reconstructions and CT scan measurements: a mean difference of 0.57 ± 0.4 mm for aortic annulus diameter and for the distance between the aortic annulus and the coronary ostia was measured. Concerning the coronary arteries, they are of paramount importance for new TARR technologies, and therefore, we tested the coronary flows of the HeartPrint Flex root at different pressure levels. At 60 mm Hg, right and left mean adjusted coronary flows were 471 and 663 ml/min; at 80 mm Hg, right and left mean coronary flows were 551 and 777 ml/min; and at 100 mm Hg, right and left mean coronary flows were 625 and 858 ml/min. In our study, 3D-printed root models correlate well with human anatomy and guarantee physiologic coronary flows for TARR technologies.
经导管主动脉根部修复（TARR）由于复杂的解剖结构仍然无法实现。为了开发未来的 TARR 技术，在进行动物试验之前，需要有一个基于人体的 bench test 模型。为此，我们旨在验证基于 CT 成像的 3D 打印根部模型在 TARR 技术中的应用。我们使用不同的树脂打印了 4 个人体 CT 衍生的根部模型：Visijet M3 Crystal、Photopolymer gel SUP705、Formlabs flexible resin 和 Materialise HeartPrint Flex。我们在主动脉位置使用 26 毫米球囊扩张式 Sapien 瓣膜进行了压力测试。太硬的 Visijet M3 Crystal 未进行测试。在其余的模型中，除了一个（比利时列日的 Materialise HeartPrint Flex）外，所有模型在测试中均发生破裂，显示出较低的壁面阻力。随后，我们在两个 HeartPrint Flex 树脂制成的根部模型中进行了进一步的测试。我们通过比较人体 CT 扫描衍生的 3D 重建和 CT 扫描测量来进行解剖验证：主动脉瓣环直径和主动脉瓣环与冠状动脉口之间的距离的平均差值分别为 0.57±0.4 毫米。关于冠状动脉，它们对于新的 TARR 技术至关重要，因此，我们测试了 HeartPrint Flex 根部在不同压力水平下的冠状动脉流量。在 60 毫米汞柱时，右冠状动脉和左冠状动脉的平均调整后的冠状动脉流量分别为 471 和 663 毫升/分钟；在 80 毫米汞柱时，右冠状动脉和左冠状动脉的平均冠状动脉流量分别为 551 和 777 毫升/分钟；在 100 毫米汞柱时，右冠状动脉和左冠状动脉的平均冠状动脉流量分别为 625 和 858 毫升/分钟。在我们的研究中，3D 打印的根部模型与人体解剖结构非常吻合，并保证了 TARR 技术的生理冠状动脉流量。
