Three-Dimensional Printing for Planning of Structural Heart Interventions

Application of cardiovascular 3-dimensional printing in Transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has been performed for nearly 20 years, with reliable safety and efficacy in moderate- to high-risk patients with aortic stenosis or regurgitation, with the advantage of less trauma and better prognosis than traditional open surgery. However, because surgeons have not been able to obtain a full view of the aortic root, 3-dimensional printing has been used to reconstruct the aortic root so that they could clearly and intuitively understand the specific anatomical structure. In addition, the 3D printed model has been used for the in vitro simulation of the planned procedures to predict the potential complications of TAVR, the goal being to provide guidance to reasonably plan the procedure to achieve the best outcome. Postprocedural 3D printing can be used to understand the depth, shape, and distribution of the stent. Cardiovascular 3D printing has achieved remarkable results in TAVR and has a great potential.

Clinical 3D modeling to guide pediatric cardiothoracic surgery and intervention using 3D printed anatomic models, computer aided design and virtual reality

BACKGROUND

Surgical and catheter-based interventions for congenital heart disease require precise understanding of complex anatomy. The use of three-dimensional (3D) printing and virtual reality to enhance visuospatial understanding has been well documented, but integration of these methods into routine clinical practice has not been well described. We review the growth and development of a clinical 3D modeling service to inform procedural planning within a high-volume pediatric heart center.

METHODS

Clinical 3D modeling was performed using cardiac magnetic resonance (CMR) or computed tomography (CT) derived data. Image segmentation and post-processing was performed using FDA-approved software. Patient-specific anatomy was visualized using 3D printed models, digital flat screen models and virtual reality. Surgical repair options were digitally designed using proprietary and open-source computer aided design (CAD) based modeling tools.

RESULTS

From 2018 to 2020 there were 112 individual 3D modeling cases performed, 16 for educational purposes and 96 clinically utilized for procedural planning. Over the 3-year period, demand for clinical modeling tripled and in 2020, 3D modeling was requested in more than one-quarter of STAT category 3, 4 and 5 cases. The most common indications for modeling were complex biventricular repair (n = 30, 31%) and repair of multiple ventricular septal defects (VSD) (n = 11, 12%).

CONCLUSIONS

Using a multidisciplinary approach, clinical application of 3D modeling can be seamlessly integrated into pre-procedural care for patients with congenital heart disease. Rapid expansion and increased demand for utilization of these tools within a high-volume center demonstrate the high value conferred on these techniques by surgeons and interventionalists alike.

Use of Virtual Reality for Hybrid Closure of Multiple Ventricular Septal Defects

A 28-month-old girl with multiple ventricular septal defects previously underwent surgical and transcatheter attempts at repair. Three-dimensional models were created from cardiac magnetic resonance–derived images. Viewing the models in virtual reality allowed the team to precisely locate the defects and decide on a hybrid transcatheter and surgical approach to ensure successful repair. (Level of Difficulty: Advanced.)

3D Printing-A Cutting Edge Technology for Treating Post-Infarction Patients

The increasing complexity of cardiovascular interventions requires advanced peri-procedural imaging and tailored treatment. Three-dimensional printing technology represents one of the most significant advances in the field of cardiac imaging, interventional cardiology or cardiovascular surgery. Patient-specific models may provide substantial information on intervention planning in complex cardiovascular diseases, and volumetric medical imaging from CT or MRI can be translated into patient-specific 3D models using advanced post-processing applications. 3D printing and additive manufacturing have a great variety of clinical applications targeting anatomy, implants and devices, assisting optimal interventional treatment and post-interventional evaluation. Although the 3D printing technology still lacks scientific evidence, its benefits have been shown in structural heart diseases as well as for treatment of complex arrhythmias and corrective surgery interventions. Recent development has enabled transformation of conventional 3D printing into complex 3D functional living tissues contributing to regenerative medicine through engineered bionic materials such hydrogels, cell suspensions or matrix components. This review aims to present the most recent clinical applications of 3D printing in cardiovascular medicine, highlighting also the potential for future development of this revolutionary technology in the medical field.

Evaluation of 3D printing in planning, practicing, and training for endovascular lower extremity arterial interventions

Background

In this study, we aimed to investigate the potential role of 3D-printed physical and digital anatomical models in pre-procedural planning, practice and training in lower extremity arterial interventions.

Methods

A total of 16 patients (9 males, 7 females; mean age: 72.1±1.5 years; range, 69 to 75 years) who underwent superficial femoral artery balloon angioplasty between February 2016 and April 2019 were retrospectively reviewed for vascular access site preference and balloon sizing. Pre-procedural computed tomography volumetric images used for diagnosis were analyzed and modeled with 3D printing. Procedural and 3D-based data regarding the size of the balloon and deployment sites and the severity of the stenosis were compared.

Results

Measurements obtained from 3D models manually and segmentation images from software were similar (p>0.05). Both were smaller than the actual size of balloons used (p<0.001). Stenosis severity was similar with manual and software methods and both were significantly lower than the reported quantitative angiographic measurements (p<0.001). Vascular access site preference was changed in five (31.2%) patients, when the model was simulated by a non-sterile practice on 3D-printed physical models. The wire and catheter selection differed in eight patients, while practicing with models.

Conclusion

The planning and practicing of lower extremity arterial procedures with 3D models may reduce operator-dependent variables, avoid unnecessary interventions, reduce endothelial damage, and increase procedural success. The 3D-printed models may be used for educational purposes for medical professionals.

3D Printing, Computational Modeling, and Artificial Intelligence for Structural Heart Disease

Structural heart disease (SHD) is a new field within cardiovascular medicine. Traditional imaging modalities fall short in supporting the needs of SHD interventions, as they have been constructed around the concept of disease diagnosis. SHD interventions disrupt traditional concepts of imaging in requiring imaging to plan, simulate, and predict intraprocedural outcomes. In transcatheter SHD interventions, the absence of a gold-standard open cavity surgical field deprives physicians of the opportunity for tactile feedback and visual confirmation of cardiac anatomy. Hence, dependency on imaging in periprocedural guidance has led to evolution of a new generation of procedural skillsets, concept of a visual field, and technologies in the periprocedural planning period to accelerate preclinical device development, physician, and patient education. Adaptation of 3-dimensional (3D) printing in clinical care and procedural planning has demonstrated a reduction in early-operator learning curve for transcatheter interventions. Integration of computation modeling to 3D printing has accelerated research and development understanding of fluid mechanics within device testing. Application of 3D printing, computational modeling, and ultimately incorporation of artificial intelligence is changing the landscape of physician training and delivery of patient-centric care. Transcatheter structural heart interventions are requiring in-depth periprocedural understanding of cardiac pathophysiology and device interactions not afforded by traditional imaging metrics.

Patient-Specific Modeling for Structural Heart Intervention: Role of 3D Printing Today and Tomorrow CME

Structural heart interventions (SHIs) are increasingly applicable in a wide range of heart defects, but the intricate and dynamic nature of cardiac structures can make SHIs challenging to perform. Three-dimensional (3D) printed modeling integrates advanced clinical imaging and 3D printing technology to replicate patient-specific anatomy for comprehensive planning and simulation of SHIs. This review discusses the basic principles of patient-specific 3D print model development, print material selection, and model fabrication and highlights how cardiovascular 3D printing can be used in preprocedural planning, device sizing, enhanced communication, and procedure simulation.

Evaluation of 3D printed carotid anatomical models in planning carotid artery stenting

Background

We aimed to investigate the potential role of threedimensional printed anatomical models in pre-procedural planning, practice, and selection of carotid artery stent and embolic protection device size and location.

Methods

A total of 16 patients (10 males, 6 females; mean age 75.6±4.7 years; range, 68 to 81 years) who underwent carotid artery stenting with an embolic protection device between January 2017 and February 2019 were retrospectively analyzed. The sizing was based on intraprocedural angiography findings with the same brand stent using distal protection device. Pre-procedural computed tomography angiography images used for diagnosis were obtained and modeled with three-dimensional printing method. Pre-procedural and threedimensional data regarding the size of stents and protection devices and implantation sites were compared.

Results

Measurements obtained from three-dimensional models manually and segmentation images from software were found to be similar and both were smaller than actually used for stent and embolic protection device sizes. The rates of carotid artery stenosis were similar with manual and software methods, but were lower than the quantitative angiographic measurements. Device implantation sites detected by the manual and software methods were different than the actual setting.

Conclusion

The planning and practicing of procedure with threedimensional models may reduce the operator-dependent variables, shorten the operation time, decrease X-ray exposure, and increase the procedural success.

What would you like to print? Students' opinions on the use of 3D printing technology in medicine

Background

Recent advances in 3D printing technology, and biomaterials are revolutionizing medicine. The beneficiaries of this technology are primarily patients, but also students of medical faculties. Taking into account that not all students have full, direct access to the latest advances in additive technologies, we surveyed their opinion on 3D printing and education in this area. The research aimed to determine what knowledge about the use of 3D printing technology in medicine, do students of medical faculties have.

Methods

The research was carried out in the form of a questionnaire among 430 students of the Medical University of Silesia in Katowice (Poland) representing various fields of medicine and health sciences. The questions included in the survey analyzed the knowledge of the respondents for 3D printing technology and the opportunities it creates in medicine.

Results

The results indicate that students do have knowledge about 3D printing obtained mainly from the internet. They would be happy to deepen their knowledge at specialized courses in this field. Students appreciated the value of 3D printing in order to obtain accurate anatomical models, helpful in learning. However, they do not consider the possibility of complete abandonment of human cadavers in the anatomy classes. Their knowledge includes basic information about current applications of 3D printing in medicine, but not in all areas. However, they have no ethical doubts regarding the use of 3D printing in any form. The vast majority of students deemed it necessary to incorporate information regarding 3D printing technology into the curriculum of different medical majors.

Conclusion

This research is the first of its kind, which allows for probing students' knowledge about the additive technologies in medicine. Medical education should be extended to include issues related to the use of 3D printing for medical applications.

Recent Applications of Three Dimensional Printing in Cardiovascular Medicine

Three dimensional (3D) printing, which consists in the conversion of digital images into a 3D physical model, is a promising and versatile field that, over the last decade, has experienced a rapid development in medicine. Cardiovascular medicine, in particular, is one of the fastest growing area for medical 3D printing. In this review, we firstly describe the major steps and the most common technologies used in the 3D printing process, then we present current applications of 3D printing with relevance to the cardiovascular field. The technology is more frequently used for the creation of anatomical 3D models useful for teaching, training, and procedural planning of complex surgical cases, as well as for facilitating communication with patients and their families. However, the most attractive and novel application of 3D printing in the last years is bioprinting, which holds the great potential to solve the ever-increasing crisis of organ shortage. In this review, we then present some of the 3D bioprinting strategies used for fabricating fully functional cardiovascular tissues, including myocardium, heart tissue patches, and heart valves. The implications of 3D bioprinting in drug discovery, development, and delivery systems are also briefly discussed, in terms of in vitro cardiovascular drug toxicity. Finally, we describe some applications of 3D printing in the development and testing of cardiovascular medical devices, and the current regulatory frameworks that apply to manufacturing and commercialization of 3D printed products.

3D Printing Applications for Transcatheter Aortic Valve Replacement

PURPOSE OF REVIEW

A combination of evolving 3D printing technologies, new 3D printable materials, and multi-disciplinary collaborations have made 3D printing applications for transcatheter aortic valve replacement (TAVR) a promising tool to promote innovation, increase procedural success, and provide a compelling educational tool. This review synthesizes the knowledge via publications and our group's experience in this area that exemplify uses of 3D printing for TAVR.

RECENT FINDINGS

Patient-specific 3D-printed models have been used for TAVR pre-procedural device sizing, benchtop prediction of procedural complications, planning for valve-in-valve and bicuspid aortic valve procedures, and more. Recent publications also demonstrate how 3D printing can be used to test assumptions about why certain complications occur during THV implantation. Finally, new materials and combinations of existing materials are starting to bridge the large divide between current 3D material and cardiac tissue properties. Several studies have demonstrated the utility of 3D printing in understanding challenges of TAVR. Innovative approaches to benchtop testing and multi-material printing have brought us closer to being able to predict how a THV will interact with a specific patient's aortic anatomy. This work to date is likely to open the door for advancements in other areas of structural heart disease, such as interventions involving the mitral valve, tricuspid valve, and left atrial appendage.

Imaging in Structural Heart Disease: The Evolution of a New Subspecialty

Structural heart disease is a new field in cardiovascular medicine, which has resulted in the creation of a new imaging subspecialty. Structural heart disease imagers have been instrumental in stimulating innovations in both the imaging and interventional spheres. Perhaps most importantly, they play a key role on the clinical heart team, interacting with team members and patients before, during, and long after a structural procedure is performed.

Three-dimensional printing in structural heart disease and intervention

Three-dimensional (3D) printing refers to the process by which physical objects are built by depositing materials in layers based on a specific digital design. It was initially used in manufacture industry. Inspired by the technology, clinicians have recently attempted to integrate 3D printing into medical applications. One of the medical specialties that has recently made such attempt is cardiology, especially in the field of structural heart disease (SHD). SHD refers to a group of non-coronary cardiovascular disorders and related interventions. Obvious examples are aortic stenosis, mitral regurgitation, atrial septal defect, and known or potential left atrial appendage (LAA) clots. In the last decade, cardiologists have witnessed a dramatic increase in the types and complexity of catheter-based interventions for SHD. Current imaging modalities have important limitations in accurate delineation of cardiac anatomies necessary for SHD interventions. Application of 3D printing in SHD interventional planning enables tangible appreciation of cardiac anatomy and allows in vitro interventional device testing. 3D printing is used in diagnostic workup, guidance of treatment strategies, and procedural simulation, facilitating hemodynamic research, enhancing interventional training, and promoting patient-clinician communication. In this review, we attempt to define the concept, technique, and work flow of 3D printing in SHD and its interventions, highlighting the reported clinical benefits and unsolved issues, as well as exploring future developments in this field.

3D modeling: a future of cardiovascular medicine

Cardiovascular disease resulting from atypical cardiac structures continues to be a leading health concern despite advancements in diagnostic imaging and surgical techniques. However, the ability to visualize spatial relationships using current technologies remains a challenge. Therefore, 3D modeling has gained significant interest to understand complex and atypical cardiovascular disorders. Moreover, 3D modeling can be personalized and patient-specific. 3D models have been demonstrated to aid surgical planning and simulation, enhance communication among surgeons and patients, optimize medical device design, and can be used as a potential teaching tool in medical schools. In this review, we discuss the key components needed to generate cardiac 3D models. We highlight prevalent structural conditions that have utilized 3D modeling in pre-operative planning. Furthermore, we discuss the current limitations of routine use of 3D models in the clinic as well as future directions for utilization of this technology in the cardiovascular field.