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) 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.
From the *Cardiac Surgery, Cardiocentro Ticino, Lugano, Switzerland
†Cardiovascular Research Unit, University Hospital of Lausanne, Lausanne, Switzerland
‡Cardiovascular Surgery, University Hospital of Basel, Basel, Switzerland
§Cardiovascular Surgery, University Hospital of Zurich, Zurich, Switzerland.
Submitted for consideration April 2018; accepted for publication in revised form August 2018.
Disclosures: The authors have no conflicts of interest to report.
This work received research grant for Cardiovascular Research Unit at University of Lausanne, Switzerland.
Correspondence: Enrico Ferrari, Cardiocentro Ticino, Via Tesserete 48, 6900 Lugano, Switzerland. Email: firstname.lastname@example.org.