Suitability of the porcine aortic model for transcatheter aortic root repair

Wang, Changtian; Lachat, Mário; Regar, Evelyn; Segesser, Ludwig Karl von; Ferrari, Enrico

doi:10.1093/icvts/ivx381

Cited by 17 publications

(15 citation statements)

References 18 publications

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“…1). However, attack angle, length and diameter of renal and coronary arteries can variate and, therefore, in order to better consider renal CG as a clinical model for the use of this technique in TARR, we compared anatomic details of patients with renal CG to standard anthropometric data of aortic root and ascending aorta extracted from the available literature and collected in a previous report [4].…”

Section: Discussionmentioning

confidence: 99%

“…Standard anthropometric data show: ascending aorta mean diameter 3 cm above the sinotubular junction: 29.3 ± 4 mm; sinotubular junction mean diameter: 27.2 ± 3 mm; Valsalva Sinuses mean diameter: 31.4 ± 3.4 mm; aortic annulus mean diameter: 23 ± 2.5 mm (Fig. 3) [4]. These data show a correspondence between the diameter of the proximal lending zone of abdominal EVAR (26.4 ± 4.3 mm) and the diameter of the healthy distal ascending aorta (29.3 ± 4 mm) (11% bigger), the TARR device distal landing zone.…”

Section: Aorta and Main Aortic Endograftmentioning

confidence: 99%

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Chimney grafts in renal arteries: a clinical model for coronary perfusion in future transcatheter aortic root repair techniques

Ferrari

Wang

Berdajs

et al. 2020

J Cardiothorac Surg

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Objectives: Given the similarities between coronary ostia and renal arteries, chimney grafts (CG) for kidney perfusion during abdominal endovascular aneurysm repair (EVAR) can be considered for coronary perfusion in future transcatheter aortic root repair (TARR) techniques. We analysed the results of renal CG and compared anatomic and technical details with root and coronary anthropometric data. Methods: Current status of kidney perfusion with CG was reviewed from literature. Anatomic details, technical data, CG performance and clinical outcome were collected and analysed. Anatomic details of aortic landing zone and renal arteries were compared with human anthropometric data of aortic root, ascending aorta and coronary ostia. Results: Seventeen articles reported 430 patients (mean age:74.5 ± 2.9 years) treated with renal CG. Mean length and diameter of proximal landing zone were 2.0 ± 2.0 mm and 26.4 ± 4.3 mm, respectively (anthropometric correspondence: ascending aorta diameter of 29.3 mm). Aortic endograft mean diameter was 26.4 ± 7.3 mm with reported oversize of 19.5 ± 6.0%. In total, 590 renal arteries were treated (left:325; right:265; bilateral:139 cases). Mean left and right renal artery diameters were 5.7 ± 0.6 mm and 5.8 ± 0.7 mm, respectively (anthropometric correspondence: coronary ostia diameters of 4.8 mm (left) and 3.7 mm (right)) with reported CG oversize of 19.75 ± 6% (left) and 18.1 ± 5.1% (right). Mean follow-up time was 16.5 ± 8.5 months, CG occlusion rate was 3.2% and endoleak I or II was reported in 83 patients (19.3%), requiring 7 procedures. Conclusions: CG provides satisfactory results in patients with suitable renal artery diameter. Based on aortic root and coronary anthropometric data, CG can be considered in future TARR technologies for coronary perfusion but further tests for flow evaluations are mandatory.

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Section: Discussionmentioning

confidence: 99%

Section: Aorta and Main Aortic Endograftmentioning

confidence: 99%

Chimney grafts in renal arteries: a clinical model for coronary perfusion in future transcatheter aortic root repair techniques

Ferrari

Wang

Berdajs

et al. 2020

J Cardiothorac Surg

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“…Although the porcine aortic root is anatomically similar to the human root, there are several differences including coronary ostia height, although this is not relevant to our model. 44,45 Relative cusp sizes also vary between humans and pigs, with the right cusp being largest and noncoronary cusp smallest in pigs, whereas in humans the noncoronary cusp is largest and left smallest. 45,46 However, overall annular dimensions, cusp depth, commissural height, and leaflet thickness are similar, making the porcine root the best animal model available.…”

Section: Discussionmentioning

confidence: 99%

“…45,46 However, overall annular dimensions, cusp depth, commissural height, and leaflet thickness are similar, making the porcine root the best animal model available. 44,45 Separating the valve from the more muscular porcine LVOT can be challenging and might affect leaflet kinematics. 47 The increased muscular support in heterografts has important ramifications during chronic use, such as increased calcification.…”

Section: Discussionmentioning

confidence: 99%

Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional–printed heart simulator

Paulsen

Kasinpila

Imbrie-Moore

et al. 2019

The Journal of Thoracic and Cardiovascular Surgery

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Objective: The optimal conduit for valve-sparing aortic root replacement is still debated, with several conduit variations available, ranging from straight tubular grafts to Valsalva grafts. Benefits of neosinus reconstruction include enhanced flow profiles and improved hemodynamics. Curiously, however, some clinical data suggest that straight grafts may have greater long-term durability. In this study, we hypothesized that straight tubular grafts may help maintain the native cylindrical position of the aortic valve commissures radially, resulting in preserved leaflet coaptation, reduced stresses, and potentially improved valve performance.Methods: Using 3D printing, a left heart simulator with a valve-sparing root replacement model and a physiologic coronary circulation was constructed. Aortic valves were dissected from fresh porcine hearts and reimplanted into either straight tubular grafts (n ¼ 6) or Valsalva grafts (n ¼ 6). Conduits were mounted into the heart simulator and hemodynamic, echocardiographic, and high-speed videometric data were collected.Results: Hemodynamic parameters and coronary blood flow were similar between straight and Valsalva grafts, although the former were associated with lower regurgitant fractions, less peak intercommissural radial separation, preserved leaflet coaptation, decreased leaflet velocities, and lower relative leaflet forces compared with Valsalva grafts.Conclusions: Valsalva grafts and straight grafts perform equally well in terms of gross hemodyanics and coronary blood flow. Interestingly, however, the biomechanics of these 2 conduits differ considerably, with straight grafts providing increased radial commissural stability and leaflet coaptation. Further investigation into how these parameters influence clinical outcomes is warranted. (J Thorac Cardiovasc Surg 2019;158:392-403) Variation (yellow arrows) between Valsalva graft and radial position of aortic commissures. Central MessageStraight grafts maintain the radial position of the aortic valve commissures in their native cylindrical conformation, preserving leaflet coaptation and decreasing regurgitation, cusp velocities, and forces. PerspectiveValve-sparing root replacement is an effective treatment for aortic root aneurysms, although the ideal conduit is unknown. While neosinus reconstruction is believed to generate more physiologic flow profiles and optimized hemodynamics, it does not appear to increase longterm clinical durability over straight grafts. Ex vivo testing was used to provide a mechanistic comparison and demonstrated decreased cusp velocities, forces, and regurgitation in straight grafts.

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“…Studies in the field of transcatheter aortic root replacement (TARR) are at their earlier phase, and, therefore, bench test models based on human anatomy will be of paramount importance before animal experimentation. 9 Three-dimensional printing is becoming popular in medicine, and, therefore, human computed tomography (CT) scan-derived 3D-printed root models can be employed to develop new technologies for TARR. [10][11][12] However, aortic roots are anatomically complex, and 3D models should not only guarantee enough resistance during the implantation of expandable endografts but also patent coronary artery ostia to test intracoronary flows after the device implantation.…”

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confidence: 99%

Suitability of 3D-Printed Root Models for the Development of Transcatheter Aortic Root Repair Technologies

et al. 2019

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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 3Dprinted 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 scanderived 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.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 m...

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Suitability of the porcine aortic model for transcatheter aortic root repair

Abstract: The porcine heart can be used as an experimental model to design and test new devices for catheter-based composite repair of the aortic root. Nevertheless, caution is required in using devices with tailored dimensions that must be adapted to the smaller pig's root.

Cited by 17 publications

References 18 publications

Chimney grafts in renal arteries: a clinical model for coronary perfusion in future transcatheter aortic root repair techniques

Chimney grafts in renal arteries: a clinical model for coronary perfusion in future transcatheter aortic root repair techniques

Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional–printed heart simulator

Suitability of 3D-Printed Root Models for the Development of Transcatheter Aortic Root Repair Technologies

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