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

Double outlet right ventricle - the 50% rule has always been about the conus

PURPOSE OF REVIEW

There has been much variability in the definition of double outlet right ventricle (DORV) spanning the last century. Historically, emphasis has been placed on the assignment of the great arteries to the right ventricle as a definition of DORV. In this review, we aim to underscore the importance of conal muscle, rather than rules surrounding assignment of great arteries to ventricles. We will be outlining the variability in patient anatomy that results from variations in conal muscle development in DORV, which may not fit perfectly into predefined constructs. This anatomic variability directly determines physiology and surgical repair options.

RECENT FINDINGS

There is a growing appreciation of the utility of cross-sectional imaging in complex DORV, and the generation of patient-specific 3D models with virtual reality simulations for surgical planning. These models improve the prediction of candidacy for biventricular repair and allow the mapping of complex baffle pathways preoperatively.

SUMMARY

DORV is not a disease entity in itself, but rather a vast spectrum of disorders associated with maldevelopment of conal muscle and often abnormal expansion of one the great vessels. Patient-specific 3D models will be crucial for improved surgical planning and patient outcomes.

Integration of case-based learning and three-dimensional printing for tetralogy of fallot instruction in clinical medical undergraduates: a randomized controlled trial

BACKGROUND

Case-based learning (CBL) methods have gained prominence in medical education, proving especially effective for preclinical training in undergraduate medical education. Tetralogy of Fallot (TOF) is a congenital heart disease characterized by four malformations, presenting a challenge in medical education due to the complexity of its anatomical pathology. Three-dimensional printing (3DP), generating physical replicas from data, offers a valuable tool for illustrating intricate anatomical structures and spatial relationships in the classroom. This study explores the integration of 3DP with CBL teaching for clinical medical undergraduates.

METHODS

Sixty senior clinical medical undergraduates were randomly assigned to the CBL group and the CBL-3DP group. Computed tomography imaging data from a typical TOF case were exported, processed, and utilized to create four TOF models with a color 3D printer. The CBL group employed CBL teaching methods, while the CBL-3DP group combined CBL with 3D-printed models. Post-class exams and questionnaires assessed the teaching effectiveness of both groups.

RESULTS

The CBL-3DP group exhibited improved performance in post-class examinations, particularly in pathological anatomy and TOF imaging data analysis (P < 0.05). Questionnaire responses from the CBL-3DP group indicated enhanced satisfaction with teaching mode, promotion of diagnostic skills, bolstering of self-assurance in managing TOF cases, and cultivation of critical thinking and clinical reasoning abilities (P < 0.05). These findings underscore the potential of 3D printed models to augment the effectiveness of CBL, aiding students in mastering instructional content and bolstering their interest and self-confidence in learning.

CONCLUSION

The fusion of CBL with 3D printing models is feasible and effective in TOF instruction to clinical medical undergraduates, and worthy of popularization and application in medical education, especially for courses involving intricate anatomical components.

Patient Screening for Self-Expanding Percutaneous Pulmonary Valves Using Virtual Reality

BACKGROUND

In recent years, self-expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for "anatomic fit," performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician-led screening of patients.

METHODS AND RESULTS

This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies' dedicated analysis for self-expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self-expandable valve was recommended by companies' dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening-in patients who received a self-expanding valve (100% versus 96.1%). When it came to screening-out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%).

CONCLUSIONS

Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self-expanding valve technologies.

Creation of Three-dimensional Anatomic Models in Pediatric Surgical Patients Using Cross-sectional Imaging: A Demonstration of Low-cost Methods and Applications

BACKGROUND

Pediatric surgery patients often present with complex congenital anomalies or other conditions requiring deep understanding of their intricate anatomy. Commercial applications and services exist for the conversion of cross-sectional imaging data into three-dimensional (3D) models for education and preoperative planning. However, the associated costs and lack of familiarity may discourage their use in centers with limited resources. The purpose of this report is to present a low-cost, reproducible method for generating 3D images to visualize patient anatomy.

METHODS

De-identified DICOM files were obtained from the hospital PACS system in preparation for assorted pediatric surgical procedures. Using open-source visualization software, variations in anatomic structures were examined using volume rendering and segmentation techniques. Images were further refined using available editing tools or artificial intelligence-assisted software extensions.

RESULTS

Using the described techniques we were able to obtain excellent visualization of desired structures and associated anatomic variations. Once structures were selected and modeled in 3D (segmentation), they could be exported as one of several 3D object file formats. These could then be retained for 3D printing, visualization in virtual reality, or as an anatomic reference during the perioperative period. Models may also be imported into commercial gaming engines for rendering under optimal lighting conditions and with enhanced detail.

CONCLUSION

Pediatric surgeons are frequently tasked with the treatment of patients with complex and rare anomalies. Visualization and preoperative planning can be assisted by advanced imaging software at minimal to no cost, thereby facilitating enhanced understanding of these conditions in resource-limited environments.

LEVEL OF EVIDENCE

V, Case Series, Description of Technique.

Immersive Innovations: Exploring the Diverse Applications of Virtual Reality (VR) in Healthcare

Virtual reality (VR) has experienced a remarkable evolution over recent decades, evolving from its initial applications in specific military domains to becoming a ubiquitous and easily accessible technology. This thorough review delves into the intricate domain of VR within healthcare, seeking to offer a comprehensive understanding of its historical evolution, theoretical foundations, and current adoption status. The examination explores the advantages of VR in enhancing the educational experience for medical students, with a particular focus on skill acquisition and retention. Within this exploration, the review dissects the applications of VR across diverse medical disciplines, highlighting its role in surgical training and anatomy/physiology education. While navigating the expansive landscape of VR, the review addresses challenges related to technology and pedagogy, providing insights into overcoming technical hurdles and seamlessly integrating VR into healthcare practices. Additionally, the review looks ahead to future directions and emerging trends, examining the potential impact of technological advancements and innovative applications in healthcare. This review illuminates the transformative potential of VR as a tool poised to revolutionize healthcare practices.

Biomimicking Atherosclerotic Vessels: A Relevant and (Yet) Sub-Explored Topic

Atherosclerosis represents the etiologic source of several cardiovascular events, including myocardial infarction, cerebrovascular accidents, and peripheral artery disease, which remain the leading cause of mortality in the world. Numerous strategies are being delineated to revert the non-optimal projections of the World Health Organization, by both designing new diagnostic and therapeutic approaches or improving the interventional procedures performed by physicians. Deeply understanding the pathological process of atherosclerosis is, therefore, mandatory to accomplish improved results in these trials. Due to their availability, reproducibility, low expensiveness, and rapid production, biomimicking physical models are preferred over animal experimentation because they can overcome some limitations, mainly related to replicability and ethical issues. Their capability to represent any atherosclerotic stage and/or plaque type makes them valuable tools to investigate hemodynamical, pharmacodynamical, and biomechanical behaviors, as well as to optimize imaging systems and, thus, obtain meaningful prospects to improve the efficacy and effectiveness of treatment on a patient-specific basis. However, the broadness of possible applications in which these biomodels can be used is associated with a wide range of tissue-mimicking materials that are selected depending on the final purpose of the model and, consequently, prioritizing some materials' properties over others. This review aims to summarize the progress in fabricating biomimicking atherosclerotic models, mainly focusing on using materials according to the intended application.

3D printing in pediatric surgery

Pediatric surgery presents a unique challenge, requiring a specialized approach due to the intricacies of compact anatomy and the presence of distinct congenital features in young patients. Surgeons are tasked with making decisions that not only address immediate concerns but also consider the evolving needs of children as they grow. The advent of three-dimensional (3D) printing has emerged as a valuable tool to facilitate a personalized medical approach. This paper starts by outlining the basics of 3D modeling and printing. We then delve into the transformative role of 3D printing in pediatric surgery, elucidating its applications, benefits, and challenges. The paper concludes by envisioning the future prospects of 3D printing, foreseeing advancements in personalized treatment approaches, improved patient outcomes, and the continued evolution of this technology as an indispensable asset in the pediatric surgical arena.

Virtual reality applications in pediatric surgery

Virtual reality modeling (VRM) is a 3-dimensional (3D) simulation. It is a powerful tool and has multiple uses and applications in pediatric surgery. Patient-specific 2-dimensional imaging can be used to generate a virtual reality model, which can improve anatomical perception and understanding, and can aid in preoperative planning for complex operations. VRM can also be used for realistic training and simulation. It has also proven effective in distraction for pediatric patients experiencing pain and/or anxiety. We detail the technical requirements and process required for VRM generation, the applications, and future directions.

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: pediatric congenital heart disease conditions

BACKGROUND

The use of medical 3D printing (focusing on anatomical modeling) has continued to grow since the Radiological Society of North America's (RSNA) 3D Printing Special Interest Group (3DPSIG) released its initial guideline and appropriateness rating document in 2018. The 3DPSIG formed a focused writing group to provide updated appropriateness ratings for 3D printing anatomical models across a variety of congenital heart disease. Evidence-based- (where available) and expert-consensus-driven appropriateness ratings are provided for twenty-eight congenital heart lesion categories.

METHODS

A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with pediatric congenital heart disease indications. Each study was vetted by the authors and strength of evidence was assessed according to published appropriateness ratings.

RESULTS

Evidence-based recommendations for when 3D printing is appropriate are provided for pediatric congenital heart lesions. Recommendations are provided in accordance with strength of evidence of publications corresponding to each cardiac clinical scenario combined with expert opinion from members of the 3DPSIG.

CONCLUSIONS

This consensus appropriateness ratings document, created by the members of the RSNA 3DPSIG, provides a reference for clinical standards of 3D printing for pediatric congenital heart disease clinical scenarios.

Cardiovascular Computed Tomography in the Diagnosis of Cardiovascular Disease: Beyond Lumen Assessment

Cardiovascular CT is being widely used in the diagnosis of cardiovascular disease due to the rapid technological advancements in CT scanning techniques. These advancements include the development of multi-slice CT, from early generation to the latest models, which has the capability of acquiring images with high spatial and temporal resolution. The recent emergence of photon-counting CT has further enhanced CT performance in clinical applications, providing improved spatial and contrast resolution. CT-derived fractional flow reserve is superior to standard CT-based anatomical assessment for the detection of lesion-specific myocardial ischemia. CT-derived 3D-printed patient-specific models are also superior to standard CT, offering advantages in terms of educational value, surgical planning, and the simulation of cardiovascular disease treatment, as well as enhancing doctor-patient communication. Three-dimensional visualization tools including virtual reality, augmented reality, and mixed reality are further advancing the clinical value of cardiovascular CT in cardiovascular disease. With the widespread use of artificial intelligence, machine learning, and deep learning in cardiovascular disease, the diagnostic performance of cardiovascular CT has significantly improved, with promising results being presented in terms of both disease diagnosis and prediction. This review article provides an overview of the applications of cardiovascular CT, covering its performance from the perspective of its diagnostic value based on traditional lumen assessment to the identification of vulnerable lesions for the prediction of disease outcomes with the use of these advanced technologies. The limitations and future prospects of these technologies are also discussed.

Multimodality Imaging Assessment of Tetralogy of Fallot: From Diagnosis to Long-Term Follow-Up

Tetralogy of Fallot (TOF) is the most common complex congenital heart disease with long-term survivors, demanding serial monitoring of the possible complications that can be encountered from the diagnosis to long-term follow-up. Cardiovascular imaging is key in the diagnosis and serial assessment of TOF patients, guiding patients' management and providing prognostic information. Thorough knowledge of the pathophysiology and expected sequalae in TOF, as well as the advantages and limitations of different non-invasive imaging modalities that can be used for diagnosis and follow-up, is the key to ensuring optimal management of patients with TOF. The aim of this manuscript is to provide a comprehensive overview of the role of each modality and common protocols used in clinical practice in the assessment of TOF patients.

Validation of a laser projection platform for the preparation of surgical patches used in paediatric cardiac surgery

OBJECTIVES

Reconstruction of cardiovascular anatomy with patch material is integral to the repair of congenital heart disease. We present validation of a laser projection platform for the preparation of surgical patches as a proof-of-concept for intraoperative use in patient-specific planning of paediatric cardiac surgery reconstructions.

METHODS

The MicroLASERGUIDE, a compact laser projection system that displays computer-aided designs onto 2D/3D surfaces, serves as an alternative to physical templates. A non-inferiority comparison of dimensional measurements was conducted between laser projection ('laser') and OZAKI AVNeo Template ('template') methods in creation of 51 (each group) size 13 valve leaflets from unfixed bovine pericardium. A digital version of the OZAKI AVNeo Template dimensions served as control. Feasibility testing was performed with other common patch materials (fixed bovine pericardium, PTFE and porcine main pulmonary artery as a substitute for pulmonary homograft) and sizes (13, 23) (n = 3 each group).

RESULTS

Compared to control (height 21.5, length 21.0 mm), template height and length were smaller (height and length differences of -0.3 [-0.5 to 0.0] and -0.4 [-0.8 to -0.1] mm, P < 0.01 each); whereas, both laser height and length were relatively similar (height and length differences of height 0.0 [-0.2 to 0.2], P = 0.804, and 0.2 [-0.1 to 0.4] mm, P = 0.029). Template percent error for height and length was -1.5 (-2.3 to 0.0)% and -1.9 (-3.7 to -0.6)% vs 0.2 (-1.0 to 1.1)% and 1.0 (-0.5 to 1.8)% for the laser. Similar results were found with other materials and sizes. Overall, laser sample dimensions differed by a maximum of 5% (∼1 mm) from the control.

CONCLUSIONS

The laser projection platform has demonstrated promise as an alternative methodology for the preparation of surgical patches for use in cardiac surgery. This technology has potential to revolutionize preoperative surgical planning for numerous congenital anomalies that require patient-specific patch-augmented repair.

Three-Dimensional Bioprinting in Cardiovascular Disease: Current Status and Future Directions

Three-dimensional (3D) printing plays an important role in cardiovascular disease through the use of personalised models that replicate the normal anatomy and its pathology with high accuracy and reliability. While 3D printed heart and vascular models have been shown to improve medical education, preoperative planning and simulation of cardiac procedures, as well as to enhance communication with patients, 3D bioprinting represents a potential advancement of 3D printing technology by allowing the printing of cellular or biological components, functional tissues and organs that can be used in a variety of applications in cardiovascular disease. Recent advances in bioprinting technology have shown the ability to support vascularisation of large-scale constructs with enhanced biocompatibility and structural stability, thus creating opportunities to replace damaged tissues or organs. In this review, we provide an overview of the use of 3D bioprinting in cardiovascular disease with a focus on technologies and applications in cardiac tissues, vascular constructs and grafts, heart valves and myocardium. Limitations and future research directions are highlighted.

Catheter-Based Techniques for Addressing Atrioventricular Valve Regurgitation in Adult Congenital Heart Disease Patients: A Descriptive Cohort

INTRODUCTION

Increasing survival of adult congenital heart disease (ACHD) patients comes at the price of a range of late complications-arrhythmias, heart failure, and valvular dysfunction. Transcatheter valve interventions have become a legitimate alternative to conventional surgical treatment in selected acquired heart disease patients. However, literature on technical aspects, hemodynamic effects, and clinical outcomes of percutaneous atrioventricular (AV) valve interventions in ACHD patients is scarce.

METHOD

This is a descriptive cohort from CAHAL (Center of Congenital Heart Disease Amsterdam-Leiden). ACHD patients with severe AV valve regurgitation who underwent a transcatheter intervention in the period 2020-2022 were included. Demographic, clinical, procedural, and follow-up data were collected from patient records.

RESULTS

Five ACHD patients with severe or torrential AV valve regurgitation are described. Two patients underwent a transcatheter edge-to-edge repair (TEER), one patient underwent a valve-in-valve procedure, one patient received a Cardioband system, and one patient received both a Cardioband system and TEER. No periprocedural complications occurred. Post-procedural AV valve regurgitation as well as NYHA functional class improved in all patients. The median post-procedural NYHA functional class improved from 3.0 (IQR [2.5-4.0]) to 2.0 (IQR [1.5-2.5]). One patient died 9 months after the procedure due to advanced heart failure with multiorgan dysfunction.

CONCLUSION

Transcatheter valve repair is feasible and safe in selected complex ACHD patients. A dedicated heart team is essential for determining an individualized treatment strategy as well as pre- and periprocedural imaging to address the underlying mechanism(s) of AV regurgitation and guide the transcatheter intervention. Long-term follow-up is essential to evaluate the clinical outcomes of transcatheter AV valve repair in ACHD patients.

Patient-Specific 3D-Printed Models in Pediatric Congenital Heart Disease

Three-dimensional (3D) printing technology has become increasingly used in the medical field, with reports demonstrating its superior advantages in both educational and clinical value when compared with standard image visualizations or current diagnostic approaches. Patient-specific or personalized 3D printed models serve as a valuable tool in cardiovascular disease because of the difficulty associated with comprehending cardiovascular anatomy and pathology on 2D flat screens. Additionally, the added value of using 3D-printed models is especially apparent in congenital heart disease (CHD), due to its wide spectrum of anomalies and its complexity. This review provides an overview of 3D-printed models in pediatric CHD, with a focus on educational value for medical students or graduates, clinical applications such as pre-operative planning and simulation of congenital heart surgical procedures, and communication between physicians and patients/parents of patients and between colleagues in the diagnosis and treatment of CHD. Limitations and perspectives on future research directions for the application of 3D printing technology into pediatric cardiology practice are highlighted.

3D Printed Models in Cardiovascular Disease: An Exciting Future to Deliver Personalized Medicine

3D printing has shown great promise in medical applications with increased reports in the literature. Patient-specific 3D printed heart and vascular models replicate normal anatomy and pathology with high accuracy and demonstrate superior advantages over the standard image visualizations for improving understanding of complex cardiovascular structures, providing guidance for surgical planning and simulation of interventional procedures, as well as enhancing doctor-to-patient communication. 3D printed models can also be used to optimize CT scanning protocols for radiation dose reduction. This review article provides an overview of the current status of using 3D printing technology in cardiovascular disease. Limitations and barriers to applying 3D printing in clinical practice are emphasized while future directions are highlighted.