Three-dimensional printing for cardiovascular diseases: from anatomical modeling to dynamic functionality

An anthropomorphic phantom for atrial transseptal puncture simulation training

BACKGROUND

Transseptal puncture (TSP) is a critical prerequisite for left-sided cardiac interventions, such as atrial fibrillation (AF) ablation and left atrial appendage closure. Despite its routine nature, TSP can be technically demanding and carries a risk of complications. This study presents a novel, patient-specific, anthropomorphic phantom for TSP simulation training that can be used with X-ray fluoroscopy and ultrasound imaging.

METHODS

The TSP phantom was developed using additive manufacturing techniques and features a replaceable fossa ovalis (FO) component to allow for multiple punctures without replacing the entire model. Four cardiologists and one cardiology trainee performed TSP on the simulator, and their performance was assessed using four metrics: global isotropy index, distance from the centroid, time taken to perform TSP, and a set of 5-point Likert scale questions to evaluate the clinicians' perception of the phantom's realism and utility.

RESULTS

The results demonstrate the simulator's potential as a training tool for interventional cardiology, providing a realistic and controllable environment for clinicians to refine their TSP skills. Experienced cardiologists tended to cluster their puncture points closer to regions of the FO associated with higher global isotropy index scores, indicating a relationship between experience and optimal puncture localization. The questionnaire analysis revealed that participants generally agreed on the phantom's realistic anatomical representation and ability to accurately visualize the TSP site under fluoroscopic guidance.

CONCLUSIONS

The TSP simulator can be incorporated into training programs, offering trainees the opportunity to improve tool handling, spatial coordination, and manual dexterity prior to performing the procedure on patients. Further studies with larger sample sizes and longitudinal assessments are needed to establish the simulator's impact on TSP performance and patient outcomes.

3D printing technology and its revolutionary role in stent implementation in cardiovascular disease

Cardiovascular disease (CVD), exemplified by coronary artery disease (CAD), is a global health concern, escalating in prevalence and burden. The etiology of CAD is intricate, involving different risk factors. CVD remains a significant cause of mortality, driving the need for innovative interventions like percutaneous coronary intervention and vascular stents. These stents aim to minimize restenosis, thrombosis, and neointimal hyperplasia while providing mechanical support. Notably, the challenges of achieving ideal stent characteristics persist. An emerging avenue to address this involves enhancing the mechanical performance of polymeric bioresorbable stents using additive manufacturing techniques And Three-dimensional (3D) printing, encompassing various manufacturing technologies, has transcended its initial concept to become a tangible reality in the medical field. The technology's evolution presents a significant opportunity for pharmaceutical and medical industries, enabling the creation of targeted drugs and swift production of medical implants. It revolutionizes medical procedures, transforming the strategies of doctors and surgeons. Patient-specific 3D-printed anatomical models are now pivotal in precision medicine and personalized treatment approaches. Despite its ongoing development, additive manufacturing in healthcare is already integrated into various medical applications, offering substantial benefits to a sector under pressure for performance and cost reduction. In this review primarily emphasizes stent technology, different types of stents, highlighting its application with some potential complications. Here we also address their benefits, potential issues, effectiveness, indications, and contraindications. In future it can potentially reduce complications and help in improving patients' outcomes. 3DP technology offers the promise to customize solutions for complex CVD conditions and help or fostering a new era of precision medicine in cardiology.

Feasibility of 3-dimensional printed models in simulated training and teaching of transcatheter aortic valve replacement

In the study of TAVR, 3-dimensional (3D) printed aortic root models and pulsatile simulators were used for simulation training and teaching before procedures. The study was carried out in the following three parts: (1) experts were selected and equally divided into the 3D-printed simulation group and the non-3D-printed simulation group to conduct four times of TAVR, respectively; (2) another 10 experts and 10 young proceduralists were selected to accomplish three times of TAVR simulations; (3) overall, all the doctors were organized to complete a specific questionnaire, to evaluate the training and teaching effect of 3D printed simulations. For the 3D-printed simulation group, six proceduralists had a less crossing-valve time (8.3 ± 2.1 min vs 11.8 ± 2.7 min, P < 0.001) and total operation time (102.7 ± 15.3 min vs 137.7 ± 15.4 min, P < 0.001). In addition, the results showed that the median crossing-valve time and the total time required were significantly reduced in both the expert group and the young proceduralist group (all P<0.001). The results of the questionnaire showed that 3D-printed simulation training could enhance the understanding of anatomical structure and improve technical skills. Overall, cardiovascular 3D printing may play an important role in assisting TAVR, which can shorten the operation time and reduce potential complications.

Application of three-dimensional printing in cardiovascular diseases: a bibliometric analysis

AIM

This paper aimed to explore the application of three-dimensional (3D) printing in cardiovascular diseases, to reach an insight in this field and prospect the future trend.

METHODS

The articles were selected from the Web of Science Core Collection database. Excel 2019, VOSviewer 1.6.16, and CiteSpace 6.1.R6 were used to analyze the information.

RESULTS

A total of 467 papers of 3D printing in cardiovascular diseases were identified, and the first included literature appeared in 2000. A total of 692 institutions from 52 countries participated in the relevant research, while the United States of America contributed to 160 articles and were in a leading position. The most productive institution was Curtin University , and Zhonghua Sun who has posted the most articles ( n =8) was also from there. The Frontiers in Cardiovascular Medicine published most papers ( n =25). The Journal of Thoracic and Cardiovascular Surgery coveted the most citations ( n =520). Related topics of frontiers will still focus on congenital heart disease, valvular heart disease, and left atrial appendage closure.

CONCLUSIONS

The authors summarized the publication information of the application of 3D printing in cardiovascular diseases related literature from 2000 to 2023, including country and institution of origin, authors, and publication journal. This study can reflect the current hotspots and novel directions for the application of 3D printing in cardiovascular diseases.

"From Vision to Reality: Virtual Reality's Impact on Baffle Planning in Congenital Heart Disease"

This study aims to evaluate the feasibility and utility of virtual reality (VR) for baffle planning in congenital heart disease (CHD), specifically by creating patient-specific 3D heart models and assessing a user-friendly VR interface. Patient-specific 3D heart models were created using high-resolution imaging data and a VR interface was developed for baffle planning. The process of model creation and the VR interface were assessed for their feasibility, usability, and clinical relevance. Collaborative and interactive planning within the VR space were also explored. The study findings demonstrate the feasibility and usefulness of VR in baffle planning for CHD. Patient-specific 3D heart models generated from imaging data provided valuable insights into complex spatial relationships. The developed VR interface allowed clinicians to interact with the models, simulate different baffle configurations, and assess their impact on blood flow. The VR space's collaborative and interactive planning enhanced the baffle planning process. This study highlights the potential of VR as a valuable tool in baffle planning for CHD. The findings demonstrate the feasibility of using patient-specific 3D heart models and a user-friendly VR interface to enhance surgical planning and patient outcomes. Further research and development in this field are warranted to harness the full benefits of VR technology in CHD surgical management.

Three-dimensional printing in modelling mitral valve interventions

Mitral interventions remain technically challenging owing to the anatomical complexity and heterogeneity of mitral pathologies. As such, multi-disciplinary pre-procedural planning assisted by advanced cardiac imaging is pivotal to successful outcomes. Modern imaging techniques offer accurate 3D renderings of cardiac anatomy; however, users are required to derive a spatial understanding of complex mitral pathologies from a 2D projection thus generating an 'imaging gap' which limits procedural planning. Physical mitral modelling using 3D printing has the potential to bridge this gap and is increasingly being employed in conjunction with other transformative technologies to assess feasibility of intervention, direct prosthesis choice and avoid complications. Such platforms have also shown value in training and patient education. Despite important limitations, the pace of innovation and synergistic integration with other technologies is likely to ensure that 3D printing assumes a central role in the journey towards delivering personalised care for patients undergoing mitral valve interventions.

3D bioprinting and its innovative approach for biomedical applications

3D bioprinting or additive manufacturing is an emerging innovative technology revolutionizing the field of biomedical applications by combining engineering, manufacturing, art, education, and medicine. This process involved incorporating the cells with biocompatible materials to design the required tissue or organ model in situ for various in vivo applications. Conventional 3D printing is involved in constructing the model without incorporating any living components, thereby limiting its use in several recent biological applications. However, this uses additional biological complexities, including material choice, cell types, and their growth and differentiation factors. This state-of-the-art technology consciously summarizes different methods used in bioprinting and their importance and setbacks. It also elaborates on the concept of bioinks and their utility. Biomedical applications such as cancer therapy, tissue engineering, bone regeneration, and wound healing involving 3D printing have gained much attention in recent years. This article aims to provide a comprehensive review of all the aspects associated with 3D bioprinting, from material selection, technology, and fabrication to applications in the biomedical fields. Attempts have been made to highlight each element in detail, along with the associated available reports from recent literature. This review focuses on providing a single platform for cancer and tissue engineering applications associated with 3D bioprinting in the biomedical field.

Physiological Ventricular Simulator for Valve Surgery Training

Surgical simulation is becoming increasingly important in training cardiac surgeons. However, there are currently no training simulators capable of testing the quality of simulated heart valve procedures under dynamic physiologic conditions. Here we describe a dynamic ventricular simulator, consisting of a 3D printed valve suspension chamber and a model 1423 Harvard apparatus pulsatile pump, which can provide close to physiologic hemodynamic perfusion of porcine aortic roots attached to the valve chamber for education and training in cardiac surgery. The simulator was validated by using it to test aortic valve leaflet repairs (n = 6) and aortic valve replacements (n = 3) that were performed by two trainees. Procedural success could be evaluated by direct visualization of the opening and closing valve, hemodynamic measurements and echocardiography. We conclude that, unlike other methods of simulation, this novel ventricular simulator is able to test the functional efficacy of aortic procedures under dynamic physiologic conditions using clinically relevant echocardiographic and hemodynamic outcomes. While validated for valve surgery, other potential applications include ascending aortic interventions, coronary re-implantation or catheter-based valve replacements.

Big Data in Cardiology: State-of-Art and Future Prospects

Cardiological disorders contribute to a significant portion of the global burden of disease. Cardiology can benefit from Big Data, which are generated and released by different sources and channels, like epidemiological surveys, national registries, electronic clinical records, claims-based databases (epidemiological Big Data), wet-lab, and next-generation sequencing (molecular Big Data), smartphones, smartwatches, and other mobile devices, sensors and wearable technologies, imaging techniques (computational Big Data), non-conventional data streams such as social networks, and web queries (digital Big Data), among others. Big Data is increasingly having a more and more relevant role, being highly ubiquitous and pervasive in contemporary society and paving the way for new, unprecedented perspectives in biomedicine, including cardiology. Big Data can be a real paradigm shift that revolutionizes cardiological practice and clinical research. However, some methodological issues should be properly addressed (like recording and association biases) and some ethical issues should be considered (such as privacy). Therefore, further research in the field is warranted.

Distensibility of Deformable Aortic Replicas Assessed by an Integrated In-Vitro and In-Silico Approach

The correct estimation of the distensibility of deformable aorta replicas is a challenging issue, in particular when its local characterization is necessary. We propose a combined in-vitro and in-silico approach to face this problem. First, we tested an aortic silicone arch in a pulse-duplicator analyzing its dynamics under physiological working conditions. The aortic flow rate and pressure were measured by a flow meter at the inlet and two probes placed along the arch, respectively. Video imaging analysis allowed us to estimate the outer diameter of the aorta in some sections in time. Second, we replicated the in-vitro experiment through a Fluid-Structure Interaction simulation. Observed and computed values of pressures and variations in aorta diameters, during the cardiac cycle, were compared. Results were considered satisfactory enough to suggest that the estimation of local distensibility from in-silico tests is reliable, thus overcoming intrinsic experimental limitations. The aortic distensibility (AD) is found to vary significantly along the phantom by ranging from 3.0 × 10⁻³ mmHg⁻¹ in the ascending and descending tracts to 4.2 × 10⁻³ mmHg⁻¹ in the middle of the aortic arch. Interestingly, the above values underestimate the AD obtained in preliminary tests carried out on straight cylindrical samples made with the same material of the present phantom. Hence, the current results suggest that AD should be directly evaluated on the replica rather than on the samples of the adopted material. Moreover, tests should be suitably designed to estimate the local rather than only the global distensibility.

Three-dimensional printed moulds to obtain silicone hearts with congenital defects for paediatric heart-surgeon training

OBJECTIVES

Many types of congenital heart disease are amenable to surgical repair or palliation. The procedures are often challenging and require specific surgical training, with limited real-life exposure and often costly simulation options. Our objective was to create realistic and affordable 3D simulation models of the heart and vessels to improve training.

METHODS

We created moulded vessel models using several materials, to identify the material that best replicated human vascular tissue. This material was then used to make more vessels to train residents in cannulation procedures. Magnetic resonance imaging views of a 23-month-old patient with double-outlet right ventricle were segmented using free open-source software. Re-usable moulds produced by 3D printing served to create a silicone model of the heart, with the same material as the vessels, which was used by a heart surgeon to simulate a Rastelli procedure.

RESULTS

The best material was a soft elastic silicone (Shore A hardness 8). Training on the vessel models decreased the residents' procedural time and improved their grades on a performance rating scale. The surgeon evaluated the moulded heart model as realistic and was able to perform the Rastelli procedure on it. Even if the valves were poorly represented, it was found to be useful for preintervention training.

CONCLUSIONS

By using free segmentation software, a relatively low-cost silicone and a technique based on re-usable moulds, the cost of obtaining heart models suitable for training in congenital heart defect surgery can be substantially decreased.

3D Printing for Medical Applications: Current State of the Art and Perspectives during the COVID-19 Crisis

The coronavirus SARS-CoV-2 pandemic has affected over one hundred million people worldwide and has resulted in over two million deaths. In addition to the toll that coronavirus takes on the health of humans infected with the virus and the potential long term effects of infection, the repercussions of the pandemic on the economy as well as on the healthcare system have been enormous. The global supply of equipment necessary for dealing with the pandemic experienced extreme stress as healthcare systems around the world attempted to acquire personal protective equipment for their workers and medical devices for treating COVID-19. This review describes how 3D printing is currently being used in life saving surgeries such as heart and lung surgery and how 3D printing can address some of the worldwide shortage of personal protective equipment, by examining recent trends of the use of 3D printing and how these technologies can be applied during and after the pandemic. We review the use of 3D printed models for treating the long term effects of COVID-19. We then focus on methods for generating face shields and different types of respirators. We conclude with areas for future investigation and application of 3D printing technology.

3D bioprinted and integrated platforms for cardiac tissue modeling and drug testing

Recent advances in biofabrication techniques, including 3D bioprinting, have allowed for the fabrication of cardiac models that are similar to the human heart in terms of their structure (e.g., volumetric scale and anatomy) and function (e.g., contractile and electrical properties). The importance of developing techniques for assessing the characteristics of 3D cardiac substitutes in real time without damaging their structures has also been emphasized. In particular, the heart has two primary mechanisms for transporting blood through the body: contractility and an electrical system based on intra and extracellular calcium ion exchange. This review introduces recent trends in 3D bioprinted cardiac tissues and the measurement of their structural, contractile, and electrical properties in real time. Cardiac models have also been regarded as alternatives to animal models as drug-testing platforms. Thus, perspectives on the convergence of 3D bioprinted cardiac tissues and their assessment for use in drug development are also presented.

Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.