State-of-the-Art Silicone Molded Models for Simulation of Arterial Switch Operation: Innovation with Parting-and-Assembly Strategy

High-resolution three-dimensional atlas of congenital heart defects based on micro-CT images of human postmortem wax-infiltrated heart specimens

INTRODUCTION

Postmortem heart specimens are essential for education and research on the anatomy, morphology, and pathology of congenital heart defects. However, such specimens are rarely obtained these days, and the specimens stored in formalin are inexorably deteriorating. This study aimed to develop methods to archive three-dimensional data of rare human heart specimens and to publish the data.

METHODS

All wax-infiltrated human postmortem heart specimens stored in the Cardiac Registry, Boston Children's Hospital were scanned using microfocus computed tomography (X-Tek HMXST225, Nikon Metrology, Inc.), and reproduced using a three-dimensional printer (Form 3B, Formlabs Inc.). The digital models were published as an interactive three-dimensional online atlas. The resolution of the three-dimensional data was evaluated.

RESULTS

The primary diagnoses in the 88 specimens included in the study include normal cardiac anatomy (11 cases), transposition of the great arteries {S,D,D} (11 cases), ventricular septal defect (10 cases), double-outlet right ventricle (9 cases), hypoplastic left heart syndrome (9 cases), and common atrioventricular canal (7 cases). Twenty-five cases (28%) underwent previous surgical or percutaneous interventions to the heart, including Mustard procedure (1 case), Senning procedure (2 cases, one was performed on a postmortem heart specimen). The median voxel size of the three-dimensional data was 40.5 um (IQR, 32.8-64.2). All intracardiac structures were precisely reproduced as digital and physical three-dimensional models.

CONCLUSIONS

The methods and resultant models were considered useful for archiving and furthering the utilization of these invaluable specimens. The atlas is available at https://www.sketchfab.com/heartmodels/collections.

Canadian radiology: 2024 update

Radiology in Canada is advancing through innovations in clinical practices and research methodologies. Recent developments focus on refining evidence-based practice guidelines, exploring innovative imaging techniques and enhancing diagnostic processes through artificial intelligence. Within the global radiology community, Canadian institutions play an important role by engaging in international collaborations, such as with the American College of Radiology to refine implementation of the Ovarian-Adnexal Reporting and Data System for ultrasound and magnetic resonance imaging. Additionally, researchers have participated in multidisciplinary collaborations to evaluate the performance of artificial intelligence-driven diagnostic tools for chronic liver disease and pediatric brain tumors. Beyond clinical radiology, efforts extend to addressing gender disparities in the field, improving educational practices, and enhancing the environmental sustainability of radiology departments. These advancements highlight Canada's role in the global radiology community, showcasing a commitment to improving patient outcomes and advancing the field through research and innovation. This update underscores the importance of continued collaboration and innovation to address emerging challenges and further enhance the quality and efficacy of radiology practices worldwide.

Longitudinal Evaluation of Congenital Cardiovascular Surgical Performance and Skills Retention Using Silicone-Molded Heart Models

Objective: Hands-on surgical training (HOST) for congenital heart surgery (CHS), utilizing silicone-molded models created from 3D-printing of patients' imaging data, was shown to improve surgical skills. However, the impact of repetition and frequency of repetition in retaining skills has not been previously investigated. We aimed to longitudinally evaluate the outcome for HOST on two example procedures of different technical difficulties with repeated attempts over a 15-week period. Methods: Five CHS trainees were prospectively recruited. Repair of coarctation of the aorta (CoA) and arterial switch operation (ASO) were selected as example procedures of relatively low and high technical difficulty. Procedural time and technical performance (using procedure-specific assessment tools by the participant, a peer-reviewer, and the proctor) were measured. Results: Coarctation repair performance scores improved after the first repetition but remained unchanged at the follow-up session. Likewise, CoA procedural time showed an early reduction but then remained stable (mean [standard deviation]: 29[14] vs 25[15] vs 23[9] min at 0, 1, and 4 weeks). Conversely, ASO performance scores improved during the first repetitions, but decreased after a longer time delay (>9 weeks). Arterial switch operation procedural time showed modest improvements across simulations but significantly reduced from the first to the last attempt: 119[20] versus 106[28] min at 0 and 15 weeks, P = .049. Conclusions: Complex procedures require multiple HOST repetitions, without excessive time delay to maintain long-term skills improvement. Conversely, a single session may be planned for simple procedures to achieve satisfactory medium-term results. Importantly, a consistent reduction in procedural times was recorded, supporting increased surgical efficiency.

Comparison of the effectiveness of three different rhinoplasty techniques to correct stenotic nostrils using silicone models: A case study

OBJECTIVE

To compare the effects of three different rhinoplasty techniques on the postoperative cross-sectional areas (CSAs) of the nares and nasal vestibuli.

STUDY DESIGN

Experimental study.

SAMPLE POPULATION

Ninety-nine 3D-printed, remolded silicone models of a single French bulldog's rostral nose.

METHODS

Models were fabricated based on a computed tomographic (CT) scan of the nose of a French bulldog with moderately stenotic nares. Each model underwent either vertical wedge resection (VW), modified horizontal wedge resection (MHW), or ala-vestibuloplasty (AVP) performed by a single surgeon (n = 33 per group). Preoperative and postoperative CT scans of the models were performed, and CSAs of the airway from the nares to the caudal end of the nasal vestibules were calculated.

RESULTS

All three rhinoplasty techniques increased CSAs (adjusted p values <.001) but to different levels caudally within the nasal vestibule. Vertical wedge resection achieved this up to the start of the alar fold, MHW up to halfway between the nares and the alar fold and AVP up to the caudal nasal vestibule. Average percentage increases in CSA were 26%, 15% and 74%, respectively. Ala-vestibuloplasty led to larger CSAs than VW and MHW from the nares to the caudal nasal vestibule (adjusted p values <.05). The proportional difference within each technique was <7%.

CONCLUSION

Ala-vestibuloplasty resulted in a larger increase in the airway CSA of silicone modeled nares and nasal vestibules of a single French bulldog in comparison with VW and MHW.

CLINICAL SIGNIFICANCE

Ala-vestibuloplasty can be considered for French bulldogs with moderately stenotic nares and evidence of nasal vestibular stenosis.

Rapid Prototyping Techniques for the Development of a Take-Home Surgical Anastomosis Simulation Model

OBJECTIVE

The objective of this paper is to describe the techniques and process of developing and testing a take-home surgical anastomosis simulation model.

DESIGN

Through an iterative process, a simulation model was customized and designed to target specific skill development and performance objectives that focused on anastomotic techniques in thoracic surgery and consist of 3D printed and silicone molded components. Various manufacturing techniques such as silicone dip spin coating and injection molding have been described in this paper and explored as part of the research and development process. The final prototype is a low-cost, take-home model with reusable and replaceable components.

SETTING

The study took place at a single-center quaternary care university-affiliated hospital.

PARTICIPANTS

The participants included in the model testing were 10 senior thoracic surgery trainees who completed an in-person training session held during an annual hands- on thoracic surgery simulation course. Feedback was then collected in the form of an evaluation of the model from participants.

RESULTS

All 10 participants had an opportunity to test the model and complete at least 1 pulmonary artery and bronchial anastomosis. The overall experience was rated highly, with minor feedback provided regarding the set- up and fidelity of the materials used for the anastomoses. Overall, the trainees agreed that the model was suitable for teaching advanced anastomotic techniques and expressed an interest in being able to use this model to practice skill development.

CONCLUSIONS

Developed simulation model can be easily reduced, with customized components that accurately simulate real-life vascular and bronchial components suitable for training of anastomoses technique amongst senior thoracic surgery trainees.

Training on Congenital 3D Cardiac Models - Will Models Improve Surgical Performance?

Technical skill development in congenital heart surgery (CHS) is challenging due to numerous factors which potentially limit the hands-on operative exposure in surgical training. These challenges have stimulated the growth of simulation-based training through the development of 3D-printed models, providing hands-on surgical training (HOST). From its inception in 2015, the models used in the HOST program have constantly improved, and now include valvar/subvalvar apparatus and better materials that mimic real tissue. Evidence shows that deliberate, regular simulation practice can improve a surgeon's technical skills across the spectrum of CHS. Furthermore, surgical trainees who undergo simulation training are able to translate this improved performance into the operative environment with improved patient outcomes. Despite evidence to support the incorporation of simulation methods into congenital training, its widespread adoption into training curricula remains low. This is due to numerous factors including funding, lack of dedicated time or proctorship and access to models-all of which can be overcome with the newer generation of models and committed trainers. Training programs should consider incorporating simulation-methods as a routine component of congenital training programs.

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.

Congenital Heart Surgery Skill Training Using Simulation Models: Not an Option but a Necessity

Congenital heart surgery (CHS) is technically demanding, and its training is extremely complex and challenging. Training of the surgeon's technical skills has relied on a preceptorship format in which the trainees are gradually exposed to patients in the operating room under the close tutelage of senior staff surgeons. Training in the operating room is an inefficient process and the concept of a learning curve is no longer acceptable in terms of patient outcomes. The benefits of surgical simulation in training of congenital heart surgeons are well known and appreciated. However, adequate surgical simulation models and equipment for training have been scarce until the recent development of three-dimensionally (3D) printed models. Using comprehensive 3D printing and silicone-molding techniques, realistic simulation training models for most congenital heart surgical procedures have been produced. Newly developed silicone-molded models allow efficient CHS training in a stress-free environment with instantaneous feedback from the proctors and avoids risk to patients. The time has arrived when all congenital heart surgeons should consider surgical simulation training before progressing to real-life operating in a similar fashion to the aviation industry where all pilots are required to complete simulation training before flying a real aircraft. It is argued here that simulation training is not an option anymore but should be a mandatory component of CHS training.