International Journal of Bioprinting RESEARCH ARTICLE Domain expert evaluation of advanced visual computing solutions and 3D printing for the planning of the left atrial appendage occluder interventions Jordi Mill1, Helena Montoliu1, Abdel H. Moustafa2, Andy L. Olivares1, Carlos Albors1, Ainhoa M. Aguado1, Elodie Medina1, Mario Ceresa1, Xavier Freixa3, Dabit Arzamendi2, Hubert Cochet4, Oscar Camara1* 1 Physense, BCN Medtech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, 08018 Spain 2 Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Barcelona, 08025, Spain 3 Department of Cardiology, Hospital Clinic de Barcelona, 08036, Spain 4 IHU Liryc, CHU Bordeaux, Université Bordeaux, Inserm 1045, Pessac, France Abstract Advanced visual computing solutions and three-dimensional (3D) printing are moving from engineering to clinical pipelines for training, planning, and guidance of complex interventions. 3D imaging and rendering, virtual reality (VR), and in-silico *Corresponding author: simulations, as well as 3D printing technologies provide complementary information Oscar Camara to better understand the structure and function of the organs, thereby improving (oscar.camara@upf.edu) and personalizing clinical decisions. In this study, we evaluated several advanced Citation: Mill J, Montoliu H, visual computing solutions, such as web-based 3D imaging visualization, VR, and Moustafa AH, et al., 2023, Domain computational fluid simulations, together with 3D printing, for the planning of the expert evaluation of advanced visual computing solutions and left atrial appendage occluder (LAAO) device implantations. Six cardiologists tested 3D printing for the planning of the different technologies in pre-operative data of five patients to identify the usability, left atrial appendage occluder limitations, and requirements for the clinical translation of each technology through interventions. Int J Bioprint, 9(1): 640. a qualitative questionnaire. The obtained results demonstrate the potential impact https://doi.org/10.18063/ijb.v9i1.640 of advanced visual computing solutions and 3D printing to improve the planning of LAAO interventions as well as the need for their integration into a single workflow to Received: May 4, 2022 be used in a clinical environment. Accepted: July 30, 2022 Published Online: November 14, 2022 Keywords: 3D printing; In silico simulations; Left atrial appendage occlusion; Pre- interventional planning; Virtual reality Copyright: © 2022 Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License, permitting distribution, 1. Introduction and reproduction in any medium, provided the original work is Computing solutions, such as three-dimensional (3D) imaging and visualization, virtual/ properly cited. augmented reality (VR/AR), in silico simulations, and visual analytics, among others, Publisher’s Note: Whioce have seen an outstanding progress in recent years. Advances and improved access to big Publishing remains neutral with and high-resolution data, hardware infrastructure (e.g., high-performance computing regard to jurisdictional claims in published maps and institutional clusters and graphical processing units), affordable devices (e.g., VR/AR headsets), and affiliations. open-source codes thanks to the commitment to open and reproducible science by Volume 9 Issue 1 (2023) 258 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion researchers, have made it possible. Biomedical applications it and try a different one[7], at the expense of increasing are not an exception, with an unprecedented availability costs, patient’s risk, and procedural time. Due to the large to medical datasets at different multi-scale and resolution variability of LA and LAA anatomy in humans, and the levels. Therefore, some visual computing technologies are wide range of device configurations, LAAO interventions already disrupting traditional concepts of medical image can clearly benefit from pre-operative planning to reduce exploration. Complex medical interventions are usually the need of device implantation attempts, thus maximizing planned by exploring pre-operative medical images, where intervention efficiency and minimizing costs. advanced visual computing solutions, in combination During LAAO interventions, multimodal 2D images with technologies such as 3D printing, could contribute to such as echocardiography and X-ray are mainly used. reduce potential complications. Nevertheless, the complexity and interpatient variability Until recently, the visualization and analysis of medical of the LAA 3D anatomy are unnoticeable under 2D imaging data were always performed with visualization imaging modalities. 3D echocardiography and, more tools, usually as two-dimensional (2D) images and recently, high-resolution computerized tomography (CT) standard multiplanar reconstruction (MPR) visualization images are increasingly becoming available, providing viewed in 2D monitors. Commonly, these are the only better spatial information of the LAA and reproducibility tools available during the intervention since they are fully than 2D-based techniques[8] to optimize the implantation integrated with the acquisition systems in the operating strategy and device selection before the intervention. room, with clinicians mentally integrating the 3D structure However, there is still a debate on which is the most and functional information provided by multiple sources. adequate imaging technique since there are discrepancies Offline image analysis can be performed with numerous on the measurements from different modalities[9]. tools, including open-source software such as 3D Slicer[1] At present, commercial solutions are available with or commercial solutions, which are usually used as the standard MPR visualization of the 3D imaging modalities stand-alone software tools tailored to specific imaging modalities and type of pathologies. (e.g., CT images) such as the 3mensio Structural Heart software (Pie Medical Imaging, Bilthoven, the In cardiology, patient-specific detailed information about Netherlands)[10], which also includes advanced 3D the structure and function of the heart is a key for medical photorealistic rendering of the heart for an advanced training, and for optimizing and personalizing clinical exploration of the LAA, or Mimics (Materialise NV, Leuven, decisions involving diagnosis, treatment planning, and post- Belgium). Karagodin et al.[11] recently demonstrated an therapeutic monitoring of patients, specifically in structural improved delineation of cardiac structures, including the heart disease, where transcatheter interventions are becoming LAA, with a new tissue transparency transillumination tool a less invasive alternative to open surgery. However, the field when visualizing 3D echocardiographic images, compared of view in transcatheter interventions is limited, with the to standard 3D rendering in a system developed by Philips absence of a gold standard open cavity surgical field depriving (Andover, MA). Most of these imaging tools to explore physicians of the opportunity for tactile feedback and visual 3D LAA anatomies are based on stand-alone software confirmation of cardiac anatomy[2]. At this juncture, there but web-based frameworks with cloud-based engines is a significant gap in understanding the 3D (plus time) are becoming modern and more flexible alternatives for anatomical and physiological relationships in the heart[3] that medical image visualization and analysis. The Virtual visual computing solutions can help to bridge. Recent studies Implantation and Device selection in the left Atrial have reviewed the added value of advanced visualization Appendages (VIDAA) platform was recently developed, of cardiac data, including applications in conditions such providing a clinician-friendly web-based tool to support as congenital heart disease[4,5], structural heart disease[2], or the pre-operative planning of LAAO interventions[12]. It transcatheter mitral valve replacement[6]. allows clinicians to interactively explore the LA geometry The left atrial appendage occlusion (LAAO), along as a 3D mesh with different computer-aided design (CAD) with a device inserted into the heart in a transcatheter LAAO models, together with some morphological indices intervention, has recently been proposed as an efficient and the original CT images in MPR format. However, these alternative for patients in atrial fibrillation (AF) with software tools are still limited in visualizing and analyzing contraindications to drug therapy. The interventional imaging data with the standard MPR, volume rendering, cardiologists need to decide the optimal type and size of and surface mesh views in 2D monitors; therefore, these the device, as well as the position where to implant it in tools have limited degrees of freedom interaction and each heart. During a LAAO procedure, if an implanted could prevent a correct perception of the 3D nature of the device seems inappropriate, the operator can recapture studied anatomy (e.g., depth and scaling). Volume 9 Issue 1 (2023) 259 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion 3D printing is a tool routinely used in certain a valuable technology in cardiology to support clinical cardiology fields, especially when dealing with abnormal decisions, such as interventional planning, diagnosis, and heart anatomies[13], such as in congenital heart disease device optimization[28,29]. For instance, the commercial and pediatric applications[14], providing the clinician a software HEARTguideTM (FEops NV, Gent, Belgium) better understanding of 3D cardiac anatomy. The clinical provides patient-specific structural simulations of LAAO translation of 3D printing has been made possible due deployments with different device configurations[30], to the reduction of printer costs with simple rigid plastic but without user interaction and lacking functional materials, although more sophisticated printers and flexible information. Computational fluid dynamics (CFD) materials mimicking tissue properties are available at a solvers compute flow and pressure throughout a well- higher cost. Adaptation of 3D printing in clinical care and defined geometrical domain and can provide useful procedural planning has already demonstrated a reduction functional information about blood flow patterns with in early operator learning curve or in centers without high spatial resolution, currently unattainable with in vivo previous experience on transcatheter interventions[2,15-17]. imaging techniques. Different therapeutic scenarios can Several studies have evaluated the added value of be in silico tested with CFD before the intervention, thus 3D-printed models for training and planning of LAAO reducing operation costs with enhanced efficiency[31] and interventions[18]. However, Conti et al. recently compared accelerating research and development understanding of 3D printing recommendations and implanted devices, with fluid mechanics within device testing[2]. Regarding LAA an agreement of only 35%[19]. Moreover, computational applications, several researchers have run CFD simulations costs and time required for models to be printed with to study blood flow in the left atria[32-35], including after the realistic materials are not negligible in the clinical workflow. implantation of LAAO to find the optimal configuration of device[12,36,37]. However, comprehensive pre-operative Although in an earlier phase of development and simulations may take between hours and days depending application in the biomedical field, there already exist on the complexity of the anatomy and potential interactions proof-of-concept studies of using VR technologies for between cardiac tissue and the blood flow to be modeled[2], cardiac devices such as the pre-operative planning of thus limiting its application in a clinical environment. transcatheter closure of cardiac deficiencies, such as In this paper, we present the evaluation of several ventricular septal[20] or sinus venous defects[21,22]. Nam et advanced visual computing solutions for the planning of al.[23] used new functionalities of the 3D-Slicer open-source LAAO interventions (i.e., web-based platform with 3D software (i.e., link with VR headsets) to develop a tool for imaging visualization, VR, and in silico fluid simulations), the virtual testing, selection, and placement of transcatheter together with 3D printing with standard and affordable device closures of atrial and ventricular septal defects. materials. 3D imaging data from CT scans of five patients, Narang et al.[24] recently demonstrated a reduction in who were the candidates for LAAO implantation, were measurement variability and time required when exploring visualized with different visual computing and 3D 3D echocardiography and CT images in different cardiac printing technologies by six domain knowledge experts pathologies, with users reporting easy manipulation of VR (three interventional and three imaging cardiologists). models, diagnostic quality visualization of the anatomy, During the practical session, they were asked to decide the and high confidence in the measurements. As for LAAO LAAO device settings after using each technology for each devices, the EchoPixel True 3D VR Solution (EchoPixel, patient-specific case, and to fill in a usability questionnaire Inc., Mountain View, California, United States) allows to and some open questions to assess the adding value, visualize CT scans and perform a “device-in-anatomy” limitations, and requirements for clinical translation of simulation for LAAO pre-procedural planning[25]. Zbronski each one of the evaluated technologies. et al.[26] also visualized CT-derived LA anatomies before and during the occlusion procedure with the AR HoloLens 2. Materials and methods headset, which is an enhancement according to clinicians. Figure 1 shows a general overview of the evaluation Finally, Medina et al.[27] developed a VR-based platform pipeline followed in our study. The original 3D CT scans (VRIDAA) for the visualization/analysis of LAA anatomies of five patients, acquired before the LAAO intervention, and the most appropriate occlusion devices to be implanted; were segmented to derive a binary mask of the left atria, the platform is regarded by clinical users as a source of including the left atrial appendage. Subsequently, a 3D motivation for trainees who can better understand the model in the form of a surface mesh was generated and required approach before the intervention. introduced, together with the gray-level 3D scan if In silico simulations from virtual physiological models required, to the specific processing workflow of each one of of the heart, also known as digital twins, are emerging as the evaluated computing technologies (e.g., web-based 3D Volume 9 Issue 1 (2023) 260 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion Figure 1. Overall pipeline for the evaluation of advanced computing technologies for the planning of the left atrial appendage occlusion (LAAO) interventions. The first step involved generating the three-dimensional (3D) surface model from the patient-specific medical images (i.e., computerized tomography, CT) of five cases. The resulting 3D model was the base for the setup of all models used in different technologies, which were tested by domain experts (i.e., physicians) in an experimental session where they needed to decide the device type, size, and position. Subsequently, the participants answered a system usability scale questionnaire and a general questionnaire with open questions. imaging, 3D printing, VR, and in silico simulations). The 120 kV in patients with body mass index (BMI) > 27 and LAAO devices selected for this study were the Amplatzer 100 kV in those with BMI < 27. Acquisition was set on end Amulet (St. Jude Medical-Abbott, St. Paul, Minnesota, systole using prospective ECG triggering, the delay being United States) and the Watchman FLX (Boston Scientific, set in percentage of the RR interval in patients in sinus Marlborough, Massachusetts, United States), with different rhythm, and in ms in those with arrhythmia. Images were sizes available commercially. Therefore, the participants acquired using a biphasic injection protocol: 1 mL/kg of of the study tested the technologies with their available Iomeprol 350 mg/mL (Bracco, Milan, Italy) at the rate of features (Section 2.3). After each technology, participants 5 mL/s followed by a 1 mL/kg flush of saline at the same chose a given device configuration and were asked to rate. A bolus tracking method was applied to acquire give a final decision on device type, size, and position to arterial phase images, and the region of interest was implant. Subsequently, a System Usability Scale (SUS) positioned within the LA. questionnaire[38] as well as some open questions (Section 2.4.6) were filled in by each physician, focusing on the 2.2. 3D model generation implantation of the tested technologies at their hospitals. For each selected patient, the anatomy of the left atria, 2.1. Clinical data including its appendage, was extracted from the CT images using semi-automatic region growing and thresholding The clinical data used in this work were provided by tools available in 3D slicer. The resulting binary mask of the Hospital Haut-Lévêque (Bordeaux, France), including AF LA was then introduced to the Marching Cubes algorithm patients that underwent a LAAO intervention and with to generate a 3D surface mesh model. Mesh smoothing was available pre-procedural high-quality CT scans. Five of them applied to correct irregularities from the segmentation, were randomly selected. The study was approved by the based on a Taubin filter smoothing operator (λ = 0.5, Institutional Ethics Committee; patients gave the informed µ = −0.53), followed by the removal of self-intersecting consent for having their data used for research purposes, faces and non-manifold edges wherever necessary using including tasks such as the ones presented in this study. MeshLab 2016.12 (http://www.meshlab.net/). The same Cardiac CT studies were performed on a 64-slice dual surface mesh of the heart was used across all the different source CT system (Siemens Definition, Siemens Medical approaches. The overall process of generating the 3D Systems, Forchheim, Germany). Tube current was set to model took around 45 min per patient. A description Volume 9 Issue 1 (2023) 261 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion of the set-up required for each evaluated computing a graph along the centerline depth to better identify local technology is provided in the following. Furthermore, size variations in the LAA. The user can also define the Table 1 illustrates the estimated preparation times and ostium (i.e., intersection between the LA and LAA) and associated costs for each technology. landing zone (i.e., where the device will be implanted) landmarks with small spheres along the centerline. 2.3. Computing technologies Afterward, based on the estimated measurements, the 2.3.1. VIDAA: Web-based exploration of 3D imaging VIDAA platform proposes a set of appropriate LAAO Both CT scans and the LA meshes were introduced to devices for the studied LAA geometry. The user can the VIDAA platform for visualization (as MPR and 3D, interactively manipulate the chosen LAAO device, respectively) and morphological analysis (Figure 2). The changing its position in the LAA and its size. Once the CT 3D surface mesh of the LA can be visualized with different and the mesh were uploaded into the VIDAA platform, levels of transparency, both in solid and wireframe the case was ready to be analyzed, with the centerline and formats. Some landmarks relevant to LAA interventions morphological measurement calculation taking less than such as the circumflex artery can be manually selected by a minute. At present, the VIDAA platform is a research the user. The centerline of the LAA was computed using prototype, and it is not available commercially. the Python’s VMTK library (https://www.vmtk.com) from 2.3.2. 3D printing the center of the LA mesh to a point on the LAA tip, the latter interactively selected by the user. Perpendicular The 3D model generated from the CT scan of each patient 2D contours along the resulting centerline were then was printed at Hospital de la Santa Creu i Sant Pau obtained to estimate morphological measurements on (Barcelona, Spain) with a Fused Deposition Modeling the LAA (i.e., maximum and minimum LAA diameters). (FDM) 3D printer, the Ultimaker S5 (Ultimaker BV, These measurements were also visualized in 2D maps and Geldermalsen, Netherlands), which costs 6000 euros Table 1. Set‑up preparation (for each patient in brackets) and practical session times as well as the associated costs for each technology Technology Set‑up preparation times (per case) Average practical session duration (per case) Cost 3D printing 43 h (26.1 h) 3 min 6000+17.5 € VIDAA 7 min (1.24 min) 8.13 min RP VRIDAA 15 min (3 min) 10 min RP+1238€+2500 PC In silico simulations 21.6 h (4.3 h) 12 min Free license+2000 PC The time required to build the 3D models, including medical image segmentation (3.75 h), are not included. RP: Research platform (i.e., no cost) Figure 2. Web-based 3D imaging exploration (VIDAA platform). Left: Morphological parameters (e.g., diameters) of 2D contours along the centerline characterizing the left atrial appendage (LAA) anatomy and range of most appropriate devices to implant. Right: 3D visualization of the LAA anatomy in a 3D wire-frame mesh format, together with the LAA centerline (white), several 2D contours and some anatomical landmarks (pink, orange, and yellow small spheres corresponding to the ostium, the landing zone, and the circumflex artery, respectively) relevant for the device implantation. Volume 9 Issue 1 (2023) 262 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion approximately. The 3D LA model was prepared for a printing with the Ultimaker Cura 3 software from the printer provider. Typical rigid polylactic acid (PLA) was the material used for the LA models (Figure 3), with an associated cost of 1.5 euros for each model. Twenty hours were needed to print all LA cases (i.e., 4 h/case). Moreover, CAD models of Amplatzer and Watchman FLX LAAO devices corresponding to the different commercially available sizes were printed with b thermoplastic polyurethane (TPU) to add more flexibility. Therefore, users could try to position the printed LAAO device into the 3D-printed model of the LA to have more insight into their interaction. The cost of all printed LAAO devices was of 10 euros, taking 22 h to print. An extra hour was added for time estimations due to pre- and c post-processing tasks, such as adding thickness to the 3D models and removing the scaffolds of all the models. 2.3.3. VRIDAA: VR tool The VRIDAA platform developed by Medina et al.[27] was used to evaluate the use of VR technologies for the planning of LAAO interventions. VRIDAA allows the user to interact with the LA geometry, jointly visualize it with patient-specific medical images in standard MPR format and relevant morphological indices (Figure 4). Standard surface manipulation, including mesh clipping Figure 3. (A) 3D-printed models of left atria (LA) analyzed in this study. and transparency changes, as well as browsing along the (B) 3D-printed models of the left atrial appendage occluder (LAAO) CT scan slices are possible. Morphological measurements devices. (C) Example of interaction between LA and LAAO 3D-printed models. and landmarks imported from the web-based VIDAA platform, such as the centerline and a graph with the associated LAA contour diameters, can be also displayed in the VR environment. It is also possible to virtually place the LAAO device of choice (i.e., different designs and sizes) in any position. In addition, the user can also plan the optimal location for introducing the delivery catheter into the LAA, freely manipulating a catheter model, together with an endoscopic view to facilitate the visualization of the LA interior. The computer used in this study was equipped with an Intel Core i5-8400 CPU @2.80 GHz processor, an NVIDIA Figure 4. Virtual reality VRIDAA platform to explore left atrial (LA) GeForce RTX 2080 Ti graphic card and 16 GB of RAM, anatomies and occluder devices. A 3D LA geometry with axial, sagittal, costing around 2000 euros. For the implementation of the and coronal slices of medical images visualized behind, together with the delivery catheter model (in white) and the 2D endoscopic view of the VRIDAA platform, the Unity Engine version 2018.1.8f1 (64- catheter’s tip camera for LAA interior visualization. bit) (Unity Technologies, San Francisco, California, United States) was used, with SteamVR as the runtime and OpenVR as the API to get full compatibility with all major meshes using the HTC Vive Pro controller to freely move VR display platforms. The employed VR headset was the it (6 degrees of freedom, i.e., rotations and translations) or HTC Vive Pro, with a resolution of 1440 × 1600 pixels zoom it to navigate inside the patient’s LA. In its current for each eye, a 90 Hz refresh rate, and 110 degrees field of implementation, the VRIDAA platform is intended to view. Its cost was of 1239 euros. Image processing outside be used with the possibility of moving within the virtual the platform was performed using Python libraries. Once environment. Thus, a clear space of around 2 m × 1.5 m is uploaded into VRIDAA, the user can interact with the 3D required. Volume 9 Issue 1 (2023) 263 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion All meshes and images were uploaded to VRIDAA identify consistent technology-related biases. At the end of before the practical session with participants. In VRIDAA, the case analysis, they were asked to make a final decision the centerline was not selected by the user; each case had a with all knowledge gathered from all technologies. Finally, centerline previously generated in the web-based VIDAA they answered the SUS questionnaire and open questions platform, as well as the measurements and the proposed for a global assessment of each employed technology. devices, which were transferred into the VR platform. The order to present the technologies in the practical Thus, if the system is already calibrated, the only required session is as follows (going from the most available to step for using the VR platform was the transfer and upload the most sophisticated technologies): CT medical images of the files to the VRIDAA system, making the workflow (optional), VIDAA, 3D printing, VRIDAA, and simulations. quite fast and straightforward. Initially, we offered the possibility of visualizing the raw CT 2.3.4. In silico flow simulations medical images of each patient. Afterward, the web-based VIDAA platform followed, since it is similar to some of the The participants were presented with the visualization most advanced software solutions commercially available in of in silico fluid simulations in the studied LA anatomies the market (e.g., 3mensio). Next, 3D printing and VRIDAA and any possible LAAO device to be implanted, using the were presented to incorporate data visualization with Ansys Discovery Live (ANSYS Inc., USA) software, under enhanced depth perception, starting with 3D printing since the Academic License (i.e., free of charge). It includes most physicians are more familiar with it. Finally, the in silico a GPU-based Lattice Boltzmann method that allows simulations were shown in the Ansys Discovery Live software almost real-time simulations, once each case was set-up. to include functional information complementary to the Therefore, the participants could manually choose a given structural knowledge provided by the other technologies. device (i.e., type and size) and place it in each position to analyze resulting blood flow patterns, which can be iterated 2.4.1. CT imaging as many times as desired. The visualization of CT medical images was optional since The volumetric meshes required for the fluid some of the physicians do not work on their daily basis simulations were generated from the 3D surface models with CT measurements. Although it was not assessed in using the Gmsh 4.5.4 software (https://gmsh.info/). SUS questionnaire, CT visualization was offered since it is The final meshes were around 800 thousand elements the gold standard technique to explore LA anatomy, thus for all cases. The PC used to run the simulations was useful to plan LAAO interventions. Moreover, there were the one used for VR. The blood flow was treated as a questions related to CT use in the general questionnaire. Newtonian fluid, with a density of 1060 kg/m3 and a Physicians could explore the CT medical images with the viscosity of 0.0035 Pa/s. The boundary conditions in Open-Source ITK-Snap software (http://www.itksnap. the inlets and outlets of the 3D LA model of the LA org/) to: (1) browse through the CT slices for inspecting were chosen as in our most recent LAA fluid simulation the LAA shape and other anatomical landmarks such as study[39], but without dynamic movement of the mitral the circumflex or the ostium and (2) take measurements of ring plane since it was not allowed in the employed these anatomical landmarks. software. Basically, they were the same for all patients, which were extracted from Doppler echo, and pressure 2.4.2. Web-based VIDAA platform measurements of an AF patient are different from the Initially, after opening the 3D LA geometry in the VIDAA ones processed in this study: A velocity profile in the platform, participants were asked to select a point to create outlet (i.e., the mitral valve) and a pressure wave at the the optimal LAA centerline. Then, the contour diameters pulmonary veins. The set-up for each simulation case perpendicular to the LAA centerline were automatically included 30 min for meshing and building, accounting computed (less than 30 s), as well as the selection for 21.6 hours in total (with 13 devices per five patients). of recommended LAAO devices. Next, participants interactively explored the LAA geometry, observing the 2.4. Practical session contour diameters and looking for the best position and Before the practical session, the participants received device for each case. In addition, physicians could select a tutorial on the different technologies, approximately among the different (recommended or not) LAAO devices lasting 1 h, demonstrating their features. During the and move them freely to decide. practical session, data from five typical LAAO patients 2.4.3. 3D printing (i.e., not particularly complicated LAA geometries) were presented to the physicians. For each case and technology, The 3D-printed model of the LA of each studied case was the participants chose the optimal device settings to offered to the physician to manipulate with their hands, Volume 9 Issue 1 (2023) 264 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion together with the full range of 3D-printed replicas of the a b Amplatzer Amulet and Watchman FLX LAAO devices available in the market. Physicians could then interact with both types of 3D-printed models to decide which device would fit each LA anatomy better. 2.4.4. Virtual reality VRIDAA platform The tasks performed by the participants on the VRIDAA platform were very similar to VIDAA. Nevertheless, the LAA centerline was already provided by default. Once the participant wore the VR glasses, the LA appeared, together c d with its centerline, and the physician could move it, grab it, or go inside to better explore the interior of the anatomical structure. Then, the user could select the type and size of a given device, which would be placed at the beginning of the centerline, which was able to move along. In addition, the LAAO device could also be grabbed and moved freely. 2.4.5. In silico simulations Initially, the participant was asked to select a device type and size, after which it could be freely placed in any location of the LAA using the interface of the Ansys Discovery Live software. The LA anatomy could also be Figure 5. (A-D) Examples of in silico fluid simulations using Ansys moved. Once a device position was chosen, the simulation Discovery Live with optimal device settings according to a given was launched, requiring several minutes to visualize the participant. 3D streamline-based visualization simulations were used to resulting blood flow patterns (Figure 5). Therefore, blood illustrate blood flow patterns of in the left atrium and left atrial appendage. flow velocities near the device could be estimated, as well Blue and red represent low velocity (< 10 m/s) and high velocities (> 20 m/s), respectively. as flow recirculations and leaks due to the chosen LAAO positioning, potentially leading to DRT. • Have you tested any of these technologies before? If 2.4.6. Evaluation questionnaires yes, which one? • Have you participated in the development of these Once the participants had gone through all the patients, technologies? If yes, which one? they answered two questionnaires: A SUS questionnaire • Which technologies would you add in your ideal and a more general questionnaire with open questions. workflow for LAAO (disregarding economical and The SUS questionnaire, developed by Brooke[38], was used equipment restrictions)? to give a more quantitative assessment on the usability of • Which technology did influence your final decision the technologies. It is a 10-item questionnaire using, in our on device election the most? case, a 7-point Likert scale. Consequently, the physicians • If your hospital is mainly using ultrasound (US) answered the SUS questionnaire for each technology imaging to plan LAAO interventions instead of CT, at the end of the session. Details on the SUS questions would you consider acquiring CT data only to be able and the answers for each technology are included in the to use these technologies? Supplementary File. The aim of the questionnaire with open questions was 3. Results to profile the participants and to know more about how 3.1. Participant profile these technologies could be implemented in their current Out of the six participants, three were interventional workflow, according to their point of view. The questions cardiologists (P2, P3, and P4), that is, physicians who were the following: are implanting the device, while the remaining three are • Years of experience in LAAO interventions. imaging cardiologists, who were responsible for the medical • Current position at the hospital. image acquisition and analysis before and during LAAO • Did you know about the application of these procedures. On average, they had 5.08 years of experience technologies to LAAO planning? If yes, which one? in LAAO interventions (with 10 years and < 1 year for the Volume 9 Issue 1 (2023) 265 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion most and less experienced, respectively). The participants technologies passed the acceptability and user-friendliness work in three different hospitals, with two of them using threshold (as defined in Bangor et al.[40]). CT images for LAAO planning while US imaging is the The web-based VIDAA platform was the best choice in the remaining clinical center. technology, according to the participants, with an average None of the participants have taken part in the score of 78.13 and two physicians considering it excellent development of VIDAA, VRIDAA, or Ansys Discovery (scores above 85). Interestingly, based on Table 2, the Live. However, one participant (P6) helped on the 3D imaging cardiologists valued VIDAA more (average of printing process but being blind to critical data in the 85.87) than the interventional cardiologists (average of study (i.e., which device was implanted, clinical output). 70.4) did, although the latter still labeled the technology Most participants (5/6) were familiar with 3D printing, as within the marginal high range of acceptability and user- they have tested it before. Moreover, only one participant friendliness. The strongest points of the VIDAA platform, did not know about the use of any of these technologies based on the SUS questions, were that it was easy to use for LAAO planning, while only one knew about all of and fast to learn without any support, with all participants them. Not a single participant had tested the VIDAA and agreeing on their willingness to use VIDAA frequently. On VRIDAA platforms before the practical session and only the other hand, the participants found that there were too two physicians had some experience with fluid simulations many features and steps in the platform, which could be beforehand, although not with the Ansys Discovery Live simplified, to perform the final LAAO planning. software. 3D printing was the second most valued technology (score of 73.3, i.e., within the acceptable range of usability), 3.2. SUS questionnaire with good marks on easiness of usability and complexity. The results of the SUS questionnaire are summarized in However, it failed on the confidence of use, consistency of Table 2 and Figure 6. Overall, all the evaluated computing the system, and a proper integration of all features. Figure 6. Overall results of the SUS questionnaire. Acceptable ranges were extracted from Bangor et al.[40]. Error bars show the standard deviation. Table 2. SUS score for each technology and participant Participant VIDAA VRIDAA 3D printing Simulations P1 (I) 88.0* 70.4 72.0 51.2 P2 (IC) 72.0* 62.4 64.0 70.4 P3 (IC) 67.2* 59.2 64.0 28.8 P4 (IC) 72.0 80.0* 78.4 73.6 P5 (I) 80.0* 62.4 68.8 48.0 P6 (I) 89.6* 75.2 92.8* 77.6 Mean (STD) 78.13 (9.24) 62.2 (8.26) 73.33 (10.96) 58.27 (18.87) I: Imaging cardiologists; IC: Interventional cardiologists. *The best computing technology according to each participant Volume 9 Issue 1 (2023) 266 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion The VR VRIDAA platform was the technology with a 3.3. Open questions on each technology wider range of answers from the participants regarding Figure 7 summarizes the answers from participants to the its use daily, with one strongly agreeing to use it and the open questions on each evaluated technology, focusing remaining ones with no clear opinion. Moreover, there on their incorporation into the clinical workflow. Three was no agreement in the participants on any major flaw physicians (all imaging cardiologists, not interventionists) of the technology. Five participants consider it easy to would add the VIDAA platform into the clinical workflow, use, although three of them reported that they might one of them only for planning complex anatomies and the need support at some point. Participants also mentioned two remaining would include also the platform for their that the devices recommended by the VRIDAA system regular cases. The VR platform, VRIDAA, was included were slightly bigger than expected. Finally, according in the workflow by only 2/6 clinicians; both used it for to the participants, most of them were confident with regular and complex planning, while half of the participants the device positioning due to the possibility of freely would use 3D printing. However, 5/6 participants found the moving. 3D-printed models very useful for exploring the anatomy The visualization of in silico fluid simulations was the and were willing to use this technology in a frequent technology with the lowest score (58.27), barely passing basis, provided the printer and flexible materials would be the usability test, in the low marginal area of acceptability cheaper. Despite the low values in the SUS questionnaire, ranges. However, it was the technology presenting the 4/6 clinicians (including the three imaging ones) would use largest variance between participants (from 77.6 to in silico fluid simulations for planning complex anatomies, 28.8), some evaluating it at the level of the remaining mainly to avoid leaks and device-related thrombus (DRT) technologies and others in the not acceptable usability after LAAO device implantation. It is worthy to point out that area. Furthermore, five participants would like to use the in silico fluid simulations are the only technology positively technology frequently, with the remaining one providing rated for follow-up purposes (2/6 participants), especially if an inconclusive answer. Moreover, they found most of the the relationship between low blood flow velocities and DRT simulation-based features useful, especially in identifying is confirmed in more extensive clinical studies. possible leaks after LAAO implantation, which is well One participant (P1) was from a hospital where CT integrated and without inconsistencies, and they felt is not routinely used for LAAO planning; US imaging quite confident on its use at the end of the practical is preferred since most patients are elderly people with session. The main reason for the overall low score was other comorbidities (e.g., renal dysfunction), often having the poor easiness of use of the Ansys Discovery Live contraindications to CT acquisition. However, the same interface; almost all participants required support and physician would be interested in acquiring CT scans to claimed that it is difficult to learn the interface, which is have access to the evaluated computing technologies when also cumbersome to use. younger patients are eligible for LAAO implantation. Figure 7. Ideal workflow according to the participants. On the left, gray shading represents imaging cardiologists, white shading represents interventional cardiologists. Volume 9 Issue 1 (2023) 267 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion Figure 7 also illustrates the extremes in physician Web: Web‑based VIDAA platform; VR: Virtual reality VRIDAA platform; 3Dpr: 3D printing; Sim: Fluid simulations; W: Watchman flex; A: Amplatzer Amulet. Numbers refer to the device size (in P6 (I) Web/VR/3Dpr/ W24/W20/W20/W20 approaches toward the use of these technologies, with W20/A18/A18/A18 A22/A22/A22/A22 A18/A18/A18/A18 A20/A18/A18/A18 one of them (P3) not willing to add any of them into the clinical workflow, and the counterpart one (P6) opting for Sim incorporating all of them. We would like to point out that P6 was the physician with more previous experience and interest on computational tools. An important remark from P6 was that a single software integrating the access to all different technologies is necessary. P5 (I) Web/VR/3Dpr/ A25/A28/A20/A28 A20/A22/A16/A22 A18/A18/A18/A18 A20/A22/A18/A22 A25/A25/A20/A25 3.4. Device selection comparison Sim Table 3 illustrates the interparticipant variation in LAAO device selection after testing each computing technology, where different patterns can be observed. For instance, participants P1 and P5 (both imaging specialists) tended to select smaller devices with 3D printing, which they attributed P4 (IC) Web/VR/3Dpr/ to the rigidity of LA walls in the printed model. Therefore, A25/A22/A22/A22 A20/A16/A16/A16 A18/A18/A18/A18 A20/A18/A18/A18 A25/A25/A25/A25 they mainly used other technologies for their final LAAO device decision. Participants P2 and P4 (both interventional Sim cardiologists) also followed the same pattern, without much LAAO size variation between different technologies. However, they were inclined to select a larger device in the VIDAA platform since it is not obvious to check for potential Table 3. Devices selected by the participants (P1 – P6) after using each computing technology leaks in it, thus overestimating the size. On the other hand, features in the VRIDAA platform (e.g., being within the A28/A22/A20/A22 A22/A22/A20/A22 A22/A22/A20/A22 A22/A22/A20/A20 A28/A28/A25/A25 VR/3Dpr/Sim LA cavity) and in silico simulations (e.g., functional flow P3 (IC) Web/ information) made these two technologies better suited for a more optimal device position to avoid leaks. Finally, mm). In bold, when the device settings coincide with the final decision made by the clinician participant P6 rarely changed the selected device after testing each technology. In three of the studied cases (C2, C3, and C4), there were substantial intraparticipant variations (e.g., more P2 (IC) Web/VR/3Dpr/ W27/W27/W20/W24 W24/W24/A25/A22 W24/A22/W20/A22 than 2 device sizes), while in the remaining cases, final A22/A18/W20/A18 A28/A25/A22/A25 decisions were quite similar. The main reason for these variations was the different LAA morphologies of the Sim two groups of cases; the first group had a so-called chicken wing-type morphology that allows a different interventional technique (e.g., sandwich) with larger LAAO device sizes, which is preferred by some physicians. Unfortunately, the sandwich technique was not considered in any of the studied technologies. On P1 (I) Web/VR/3Dpr/ A25/A22/A16/A22 A20/A18/A16/A16 A22/A20/A16/A18 A20/A20/A18/A18 A25/A25/A18/A22 the other hand, the agreement in the non-CW LAA cases (i.e., C1 and C5) was higher, as can be seen in Table 3. Sim Shockingly, none of the participants proposed the LAAO device, which was finally implanted in case C4. Table 4 shows the final LAAO devices selected for each participant in all studied cases, compared to the device effectively implanted in the patient. Most LAAO devices selected by participants were the Amplatzer Amulet since Case no. it was the device mainly used in their training period and C1 C2 C3 C4 C5 they had more experience with it. Therefore, they felt more Volume 9 Issue 1 (2023) 268 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion comfortable using it. It can be observed in Table 4 that in 3D printing solutions are complementary, all providing most cases, participants chose up to three different LAAO added value in different steps of the current LAAO clinical device sizes, generally (63% of the times) not matching workflow. All the evaluated technologies passed the the implanted one and with some extreme choices (C4 in threshold of acceptability range on usability; the web-based Table 4, with A18 and A25 being selected). VIDAA platform and 3D printing were better rated, and the former getting excellent marks from some participants. 4. Discussion The VR-based platform (VRIDAA) and in silico simulations The fields of visual computing and 3D printing have seen were placed in the high and low marginal ranges, a considerable progress over the last few years, slowly respectively, but huge discrepancies between participants providing solutions for advanced visualization in some existed in the latter. However, we need to consider that biomedical applications. According to a recent review previous experience on the technologies could influence by Wang[2], a well-known cardiology leader in the field the usability score (e.g., P4 and P6 being the only users with of LAAO interventions, 3D printing, computational some knowledge on simulations gave them the best scores). modeling, and artificial intelligence (AI) plays a role in Nonetheless, the main overall conclusions among the bridging the dichotomy of real-world in the trenches participants were the complementarity of the technologies imaging and futuristic capabilities of computer science and and the need for an integrative unique platform of the biomedical engineering. Pre-planning complex cardiology visual computing technologies (i.e., VIDAA, VRIDAA, procedures such as LAAO with visual computing and 3D and fluid simulations) to be incorporated into the clinical printing technologies can be beneficial in maximizing workflow and used on a daily basis. In addition, a more interventional efficiency and minimizing costs, which realistic elastic behavior of the 3D-printed LAAO devices are estimated by procedural time and device expenditure. would increase the precision on the selected settings. However, the clinical translation of advanced visualization One of the most valued features in the web-based technologies is not straightforward, needing to fulfill the VIDAA platform was the detailed characterization of the demanding requirements to be embedded in the existing LAA anatomy, with the diameters along the centerline, workflows in hospitals. For instance, clinicians will not since it can be used to identify the optimal implantation invest more than a few minutes on planning cases that can or to better plan special strategies such as the sandwich take 30 min for the intervention. Moreover, pre-planning technique. However, the manual selection of seed points should not add excessive complexity and cost to the overall for the centerline was an important factor to properly clinical workflow; therefore, sufficient cost-effectiveness characterize the LAA anatomy and select the appropriate or patient safety impact must be proven to justify their device and its position. In addition, based on the SUS routine use. questionnaire, VIDAA was fast and intuitive, which Despite recent generic reviews of visual computing covered several manual steps but with a fast learning solutions in cardiology applications[2,4-6], there is a lack curve. Participants stressed the added value of the web- of complete studies testing the different visualization based platform in complex cases, proposing to incorporate methodologies on the same patient-specific data for functional information from fluid simulations for a more benchmarking purposes. To the best of our knowledge, complete solution. The current commercial solutions our study is the first attempt on this direction focusing on comparable to VIDAA are the stand-alone 3mensio LAAO interventions, aiming at evaluating the added value, Structural Heart software (Pie Medical Imaging, Bilthoven, limitations, and requirements for the clinical translation the Netherlands) or Mimics (Materialise NV, Leuven, of these technologies. The results obtained in the practical Belgium), which include MPR visualization, 3D rendering, session demonstrated that the tested visual computing and and 3D surface visualization, and HEARTguideTM Table 4. Devices finally selected by the participants Case P1 (I) P2 (IC) P3 (IC) P4 (IC) P5 (I) P6 (I) Implanted C1 A22* A25 A22* A22* A28 A22* A22 C2 A18 A18 A22 A16* A22 A18 A16 C3 A20 A22 A22 A18* A22 A18* A18 C4 A20 W24 A20 A18 A22 A18 A25 C5 A22 A25* A25* A25* A25* W20 A25 W: Watchman flex; A: Amplatzer Amulet. Numbers refer to the device size (in mm). *The cases that matched the size of the device implanted to the patient Volume 9 Issue 1 (2023) 269 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion (FEOPS NV, Gent, Belgium), which offers simulations the geometries should be opened in half to facilitate free of device deployment. The VIDAA platform provides movement of the device in the printed model. Despite its a more comprehensive and interactive morphological limitations, most physicians thought 3D printing was the characterization of the LAA, as well as interaction with 3D best technology to recognize the shape and do a mental models of the LAA devices in a web-based environment quick strategy of the intervention for regular planning. that does not require any software installation and easily In silico fluid simulations including LAAO devices allows multicentric studies and collaborative decisions. were a unique source of valuable functional information, Moreover, none of these solutions offer in silico fluid not available from current imaging modalities or other simulations. The price of these commercial software tools computing solutions. Imaging cardiologists particularly can also be an obstacle for including them in the clinical valued this option for evaluating regions with potential leaks workflow of some hospitals. and complex flow after the LAAO implantation. However, Participants in our study acknowledged the better the Ansys Discovery Live interface, which is difficult to exploration of the 3D LAA anatomy with the VR system, interact with or move the CAD model of the device, was due to an enhanced depth perception, 6 degrees of freedom not as user-friendly as the remaining technologies, as interaction with 3D objects (both the LA geometry and the quantified in the SUS questionnaire. Participants would device) and views from the interior of the cavity (not easy not include this technology in its current form, but they to see even in 3D-printed models), all points important for would recommend incorporating it in other tools such as the device implantation[27]. For example, it was challenging VIDAA or VRIDAA. However, to integrate in silico fluid for participants to truly grasp the depth and scaling of simulations in device-related decision-making, enough human organs and device sizes (as well as their relation) credibility still needs to be built following verification, only from 2D monitors, especially to detect possible validation, and uncertainty quantification standards such leaks. Although the learning times for using the VRIDAA as the V&V40 guidelines[41], including sensitivity analysis platform were short (i.e., a few minutes), the participants to identify the boundary conditions to provide more the preferred the combination of web-based 3D imaging realistic fluid simulations[39]. Moreover, the employed fluid software in conjunction with 3D printing since it would be solver allowed user-interaction for estimating changes in easier to fit in the current clinical workflow. The evaluated blood flow patterns with different device positions, but VR setup that requires a certain allocated physical space is at the expense of simplifications (e.g., absence of wall not adequate for use in most hospitals. However, affordable motion) that could be relevant to better mimicking of the VR headsets with reasonable performance and resolution, interaction between the device and the anatomy[42]. including wireless solutions without requiring much room The comparison between the devices selected by the space (e.g., the Oculus brand or even AR glasses), would be participants after each technology demonstrated the a more appropriate alternative. relevance for interventional cardiologists to explore the 3D printing emerged as a useful technology for rapid data and anatomy fully in three dimensions with systems prototyping, testing, and pre-operative planning. However, such as VR and including functional information from flow the use of cheap materials in our study was a limiting simulations. In addition, there were consistent differences factor since it did not realistically mimic the left atrial wall in device sizes selected with 2D-based tools compared elastic properties, which are important to determine the to 3D alternatives. Beyond computational tools, there interaction with the device once implanted. Specifically, it are other reasons related to the current LAAO clinical made physicians pick sizes smaller than the one implanted workflow and training that could explain the large variation or selected with the other technologies. The use of more on device sizing by different clinicians. For instance, the realistic materials, such as the transparent and flexible existing manufacturer’s sizing recommendations overlap, HeartFlex from Materialise NV (Leuven, Belgium) or resin, so a situation where a given LAA measurement could was also noted by the participants, but would dramatically be covered by more than 1 device size might occur. The increase the costs of the technology (approximately 200 consequence is that some clinicians would favor larger or euros per piece vs. 1.5 euros with PLA). In addition, the smaller sizes in a subjective way (e.g., device manufacturer’s use of real LAA occluders rather than 3D replicas could recommendation of 22 mm, some opting for 20 mm, and improve the realism of the planning, but it will require others for 25 mm), increasing the importance of their access to all LAAO designs and sizes, which is often not experience on the procedure for a successful LAAO possible. Moreover, it was difficult to manipulate the implantation. Even with industry-supported training, LAAO device inside the 3D-printed model since the only experienced clinicians selected a wide range of LAAO open holes were the pulmonary veins and the mitral valve; device sizes. The integration of pre-operative planning Volume 9 Issue 1 (2023) 270 https://doi.org/10.18063/ijb.v9i1.640 International Journal of Bioprinting Evaluation of advanced visual computing solutions for the left atrial appendage occlusion techniques into the industrial training programs would images could also be used in the presented visual computing help further standardize LAAO implantation procedures. solutions, mainly with advanced 3D rendering or in VR Effectively, physicians highlighted the potential role of 3D setups[11,24], but anatomical details of the structures under printing and the VR VRIDAA platform for training clinical study will be lost, which could negatively affect the medical fellows, especially on challenging cases. A complementary decisions on the devices to implant. Otherwise, the manual and very important use of these technologies according to steps and time required for creating the 3D models from domain experts involves patient education, which could the original medical images could be a limitation for the contribute to reduce the levels of stress and anxiety before clinical translation of the evaluated tools. Nevertheless, the intervention thanks to a better understanding of the the use of automatic deep learning techniques for LA procedure. A final comment was related to the application segmentation and mesh creation is being developed and of the assessed computing solutions to other structural should be available soon. Furthermore, it would have heart disease procedures involving medical devices such been useful to include new photorealism and advanced as transaortic valvular interventions since the technologies cinematic rendering visualization[11] in our study, which would only need slight modifications from the current will be planned in the future. In addition, other anatomical LAAO-based use case. structures, relevant for the LAAO procedure, such as the fossa ovalis for guiding catheters into the LA, should be There are some limitations in our study. First, only incorporated in different computing technologies for a a small cohort consisting of six participants was able more complete planning of the intervention. Finally, an to evaluate the computing technologies. Moreover, all evaluation study where the advanced visual computing participants were trained with a single LAAO device solutions are implemented and tested in the hospital (Amplatzer Amulet), thus undoubtedly creating some bias would complete the current work, where the technologies favoring such a device. Furthermore, the disagreements were tested by domain experts in a research laboratory. found between the final selected and the implanted devices may be misleading since follow-up information was not 5. Conclusions available for the analyzed cases; therefore, the implanted device could not be ideal, eventually leading to abnormal In this work, we evaluated several computing technologies to events at some point. assess their added value, limitations, and requirements before they are translated to a clinical environment, particularly Another possible factor that could impact the evaluation for the planning of left atrial appendage occlude (LAAO) of the technologies is that the same five cases were analyzed interventions. All the evaluated technologies could be by the users, following the same order, which could lead beneficial in different steps of the LAAO clinical workflow, to a model learning effect: Participants remembered their even if most need some adaptation to fit in the hospital choices with previously tested technologies, making their routine. Specifically, the web-based 3D imaging VIDAA analysis not fully independent. The rationale of the chosen platform provided a complete morphological characterization order was going from the most clinically available to the and excellent user interaction to manipulate and test multiple most sophisticated technologies, but a more randomized device configurations. Economical 3D-printed models, study that includes more cases should be performed in the although lacking completely realistic device-LAA interaction, future to alleviate the learning effect. Using computational were useful to have a better perception of the 3D LAA anatomy tools that all had been developed by the authors provided an and can be easily integrated in the current clinical workflows. unbiased analysis toward the preferred technology or which VR technologies, which are especially suited for educational one should be considered the best. On the other hand, or pre-operative planning purposes, were also very helpful the maturity of the individual instance of each technology for 3D perception, but only simple VR headsets would be certainly had an influence on the evaluation results, not suitable for daily clinical routine. In silico fluid simulations necessarily reflecting the technology potential. For instance, with LAAO devices have potential to reduce the risk of leaks in silico fluid simulations could obtain better scores with a and device-related thrombus after the implantation but more mature user interface while 3D printing would be better required more user-friendly interfaces. In consequence, all the assessed with more realistic, soft, and elastic materials[43]. evaluated computing technologies could contribute to better However, the present study successfully identified the most personalization of LAA intervention and post-interventional relevant aspects to consider in each technology for clinical treatment to each patient, which helps ensure better outcomes. translation, beyond individual instances. Advanced versions of the studied computing solutions will In addition, we evaluated all computing technologies be properly embedded in clinical workflows soon, especially on 3D models built from CT medical images, which are not if they can be all integrated into a single space or software always available for LAAO planning. Echocardiography platform, as most participants of this study demanded. 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