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.

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.

Congenital Absence of Pericardium: A Case Report and Technical Considerations in Cardiac Surgery.

This case report describes a rare instance of left-sided congenital pericardial agenesis (CPA) encountered during coronary artery bypass grafting (CABG) in a 77-year-old male. In this unique case, the presence of an unusual strip of left pericardium containing the phrenic nerve posed significant surgical challenges. Special attention was required for the graft lay, ensuring adequate filling of the heart during assessment before closure, as well as emphasis on the need for generous graft length. Additionally, the evaluation of graft positioning prior to cardiopulmonary bypass was crucial. Despite these complexities, CABG was successfully performed with no complications to note. This case underscores the importance of adaptability in surgical technique to manage the unique challenges posed by CPA, leading to a positive outcome despite the atypical cardiac anatomy.

Aprotinin in high-risk isolated coronary artery bypass graft patients: a 3-year propensity matched study.

BACKGROUND: Aprotinin, a serine protease inhibitor, has been used variably in cardiac surgery amidst ongoing debates about its safety following several previous studies. This study assesses the outcomes of aprotinin in high-risk isolated Coronary Artery Bypass Graft (iCABG) patients. METHODS: The study retrospectively analysed a cohort of 1026 iCABG patients, including 51 patients who underwent aprotinin treatment. Logistic regression powered score matching was employed to compare aprotinin patients with a control group, in a propensity-matched cohort of 96 patients. The primary outcome measured was in-hospital death, with secondary outcomes including renal dysfunction, stroke, myocardial infarction, re-exploration for bleeding or tamponade, and postoperative stay durations. RESULTS: The aprotinin cohort had high-risk preoperative patients with significantly higher EUROSCORE II values, 7.5 (± 4.2), compared to 3.9 (± 2.5) in control group. However, aprotinin group showed no statistically significant increase (p-value: 0.44) in hospital mortality with OR 2.5 [95% CI 0.51, 12.3]. Major secondary outcome rates of renal replacement therapy and postoperative stroke compared to the control group were also statistically insignificant between the two groups. CONCLUSION: This study suggests that aprotinin may be safely used in a select group of high-risk iCABG patients. The reintroduction of aprotinin under specific conditions reflects its potential benefits in managing bleeding in high-risk surgeries, but also underscores the complexity of its risk-benefit profile in such critical care settings. Nonetheless, it highlights the importance of carefully selecting patients and conducting additional research, including larger and more controlled studies to fully comprehend the potential risks and benefits of aprotinin.

20 Years of triple-valve surgery in the UK: demographic and outcome trends.

OBJECTIVES: To describe evolving demographic trends and early outcomes in patients undergoing triple-valve surgery in the UK between 2000 and 2019. METHODS: We planned a retrospective analysis of national registry data including patients undergoing triple-valve surgery for all aetiologies of disease. We excluded patients in a critical preoperative state and those with missing admission dates. The study cohort was split into 5 consecutive 4-year cohorts (groups A, B, C, D and E). The primary outcome was in-hospital mortality, and secondary outcomes included prolonged admission, re-exploration for bleeding, postoperative stroke and postoperative dialysis. Binary logistic regression models were used to establish independent predictors of mortality, stroke, postoperative dialysis and re-exploration for bleeding in this high-risk cohort. RESULTS: We identified 1750 patients undergoing triple-valve surgery in the UK between 2000 and 2019. Triple valve surgery represents 3.1% of all patients in the dataset. Overall mean age of patients was 68.5 ± 12 years, having increased from 63 ±12 years in group A to 69 ± 12 years in group E (P < 0.001). Overall in-hospital mortality rate was 9%, dropping from 21% in group A to 7% in group E (P < 0.001). Overall rates of re-exploration for bleeding (11%, P = 0.308) and postoperative dialysis (11%, P = 0.066) remained high across the observed time period. Triple valve replacement, redo sternotomy and poor preoperative left ventricular ejection fraction emerged as strong independent predictors of mortality. CONCLUSIONS: Triple-valve surgery remains rare in the UK. Early postoperative outcomes for triple valve surgery have improved over time. Redo sternotomy is a significant predictor of mortality. Attempts should be made to repair the mitral and/or tricuspid valves where technically possible.

Outcomes of cardiac surgical procedures performed by trainees versus consultants: A systematic review with meta-analysis.

OBJECTIVES: Cardiac surgery is highly demanding and the ideal teaching method to reach competency is widely debated. Some studies have shown that surgical trainees can safely perform full operations with equivocal outcomes compared with their consultant colleagues while under supervision. We aimed to compare outcomes after cardiac surgery with supervised trainee involvement versus consultant-led procedures. METHODS: We systematically reviewed databases (PubMed/MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Google Scholar) and reference lists of relevant articles for studies that compared outcomes of cardiac surgery performed by trainees versus consultants. Primary end points included: operative mortality, coronary events, neurological/renal complications, reoperation, permanent pacemaker implantation, and sternal complications. Secondary outcomes included cardiopulmonary bypass and aortic cross-clamp times and intensive care/in-hospital length of stay. Random effects meta-analysis was performed. RESULTS: Thirty-three observational studies that reported on a total of 81,616 patients (trainee: 20,154; consultant: 61,462) were included. There was a difference favoring trainees in terms of operative mortality in the main analysis and in an analysis restricted to propensity score-matched samples, whereas other outcomes were not consistently different in both analyses. Overall cardiopulmonary bypass and aortic cross-clamp times were longer in the trainee group but did not translate in longer intensive care unit or hospital stay. CONCLUSIONS: In the right conditions, good outcomes are possible in cardiac surgery with trainee involvement. Carefully designed training programs ensuring graduated hands-on operative exposure as primary operator with appropriate supervision is fundamental to maintain high-quality training in the development of excellent cardiac surgeons.

State-of-the-art silicone molded models for simulation of arterial switch operation: Innovation with parting-and-assembly strategy.

Background: Three-dimensional (3D) printed models are widely accepted for use in training of various surgical procedures for congenital heart disease; however, their physical properties have been considered suboptimum for procedures. We created silicone molded models produced using a novel "parting and assembly" strategy and compared their suitability for hands-on training with that of conventional 3D printed models. Methods: Computed tomography imaging data from 2 patients with transposition of the great arteries were used. The heart was divided into multiple parts (atria, ventricles, great arteries, coronary arteries, and valves), and molds of each part were created. The parts reproduced by silicone molding were assembled using an adhesive agent. In an online course, 2 silicone molded models and 1 3D printed model were used for training of 34 surgeons. A questionnaire was distributed to these surgeons aimed at assessing the suitability of the models for the arterial switch operation (ASO). Results: The silicone molded models showed excellent anatomic detail, high elasticity, and high resistance to tearing. The cost per model, based on the production of 50 models, was slightly higher for the silicone molded models compared with the 3D printed models. All 26 surgeons who completed the questionnaire reported that the silicone molded models provided sufficient anatomic information, but only 19% said the same for the 3D printed models. All surgeons also considered the silicone models to be realistic when passing a needle, cutting vessels, suturing, and excision of the coronary buttons, as opposed to <46% for the 3D printed models. Conclusions: Silicone molding of models for the ASO is feasible by applying a "parting and assembly" strategy. Silicone molded models provide excellent physical properties that are far superior to those of 3D printed models for surgical simulation.

Digital communication platforms in cardiothoracic surgery during COVID-19 pandemic: keeping us connected or isolated?

During the COVID-19 pandemic, performing a surgeon's duties has become challenging while adhering to social distancing mandates. To aid in the continuity of healthcare services, rapid implementation of digital communication tools became a necessity. This is an account of experiences using digital communication platforms, namely Microsoft Teams and Zoom, for clinical and educative purposes in the field of Cardiothoracic Surgery in the UK. While enabling ongoing virtual clinical meetings, conferences and learning opportunities for residents with little face-to-face contact, are these digital communication platforms keeping us connected or isolated?

Is it time to incorporate hands-on simulation into the cardiothoracic surgery curriculum?

The COVID pandemic has had huge implications for training in cardiothoracic surgery. The reduction in training opportunities has led to concerns from trainees globally regarding the impact on their learning and their training progression. Surgical simulation is effective in the development of technical skills in cardiothoracic surgery with numerous examples of low and high-fidelity simulators. Despite this the incorporation of such methods into training curricula worldwide is seldom. Core fundamentals are required to successfully implement surgical simulation into training programmes, which includes; commitment from trainers, regular sessions and structured feedback. Few programmes have demonstrated the successful incorporation of surgical simulation and there is a growing acceptance of its place in the speciality. As we recover from this challenging period it may be the right opportunity to evolve how we train our current and future trainees by incorporating hands-on simulation as a fundamental part of the cardiothoracic curriculum.

Clinical translation of surgical simulated closure of a ventricular septum defect.

OBJECTIVES: To demonstrate that improvement in technical performance of congenital heart surgical trainees during ventricular septum defect (VSD) closure simulation translates to better patient outcomes. METHODS: Seven trainees were divided into 2 groups. Experienced-fellows group included 4 senior trainees who had performed >5 VSD closures. Residents group consisted of 3 residents who had never performed a VSD closure. Experienced-fellows completed 3 VSD closures on real patients as a pretest. Both groups participated in a 4-week simulation requiring each participant to complete 2 VSD closures on three-dimensional printed models per week. One month later, all trainees returned for a post-test operation in real patients. All performances were recorded, blinded and scored independently by 2 cardiac surgeons using the validated Hands-On Surgical Training-Congenital Heart Surgery (HOST-CHS). Predefined surgical outcomes were analysed. RESULTS: The median HOST-CHS score increased significantly from week 1 to 4 [50 (39, 58) vs 73 (65, 74), P < 0.001] during simulation. The improvement in the simulation of experienced-fellows successfully transferred to skill acquisition [HOST-CHS score 72.5 (71, 74) vs 54 (51, 60), P < 0.001], with better patients outcomes including shorter total cross-clamp time [pretest: 86 (70, 99) vs post-test: 60 (53, 64) min, P = 0.006] and reduced incidence of major patch leak requiring multiple pump runs [pretest: 4/11 vs post-test: 0/9, P = 0.043]. After simulation, the technical performance and surgical outcomes of Residents were comparable to Experienced-fellows in real patients, except for significantly longer cross-clamp time [Residents: 76.5 (71.7, 86.8) vs Experienced-fellows: 60 (53, 64) min, P = 0.002]. CONCLUSIONS: Deliberate practice using simulation translates to better performance and surgical outcomes in real patients. Residents who had never completed a VSD closure could perform the procedures just as safely and effectively as their senior colleagues following simulation.

The use of objective assessments in the evaluation of technical skills in cardiothoracic surgery: a systematic review.

OBJECTIVES: With reductions in training time and intraoperative exposure, there is a need for objective assessments to measure trainee progression. This systematic review focuses on the evaluation of trainee technical skill performance using objective assessments in cardiothoracic surgery and its incorporation into training curricula. METHODS: Databases (EBSCOHOST, Scopus and Web of Science) and reference lists of relevant articles for studies that incorporated objective assessment of technical skills of trainees/residents in cardiothoracic surgery were included. Data extraction included task performed; assessment setting and tool used; number/level of assessors; study outcome and whether the assessments were incorporated into training curricula. The methodological rigour of the studies was scored using the Medical Education Research Study Quality Instrument (MERSQI). RESULTS: Fifty-four studies were included for quantitative synthesis. Six were randomized-controlled trials. Cardiac surgery was the most common speciality utilizing objective assessment methods with coronary anastomosis the most frequently tested task. Likert-based assessment tools were most commonly used (61%). Eighty-five per cent of studies were simulation-based with the rest being intraoperative. Expert surgeons were primarily used for objective assessments (78%) with 46% using blinding. Thirty (56%) studies explored objective changes in technical performance with 97% demonstrating improvement. The other studies were primarily validating assessment tools. Thirty-nine per cent of studies had established these assessment tools into training curricula. The mean ± standard deviation MERSQI score for all studies was 13.6 ± 1.5 demonstrating high validity. CONCLUSIONS: Despite validated technical skill assessment tools being available and demonstrating trainee improvement, their regular adoption into training curricula is lacking. There is a need to incorporate these assessments to increase the efficiency and transparency of training programmes for cardiothoracic surgeons.

Basic principles of cardiothoracic surgery training: a position paper by the European Association for Cardiothoracic Surgery Residents Committee.

OBJECTIVES: Across Europe there are significant variations in the fundamental structure and content of cardiothoracic surgery (CTS) training programmes. Previous efforts have been made to introduce a Unified European Training System, which outlined the fundamentals of the ideal programme and supported a paradigm shift from an apprenticeship to a competency-based model. This article's goal was to define key structural, administrative and executive details of such a programme to lay the foundations for the standardization of cardiothoracic surgical training across Europe. METHODS: The European Association for Cardiothoracic Surgery Residents Committee had previously conducted a residents' training survey across Europe in 2020. Training curricula from the twelve most represented countries across Europe were either searched online or obtained from the countries' national trainee representative and reviewed by the committee. Information was collated and placed into one of the following categories to develop the position paper: (i) selection of eligible candidates, (ii) guidance for an outcome-based syllabus, (iii) documentation and evaluation of training progress, (iv) mandatory rotations and training courses, (v) number of independent or assisted cases and (vi) requirements and quality assurance of teachers. RESULTS: An independent professional body should promote an outcome-based syllabus and take responsibility for the training programme's quality assurance. Trainees should be selected on merit by an open and transparent process. Training should be delivered within a defined period and supervised by an appointed training committee to ensure its implementation. This committee should review the trainees progression regularly, provide feedback and offer trainees the opportunity to experience various training environments and trainers. A common electronic portal be used by trainees to record their agreed objectives and to evidence their completion. Trainees should regularly attend specialty-relevant courses and conferences to promote professional and academic development. The end of training is reached when the formal requirements of the training programme are met and the trainee is able to perform at the level expected of a day-1 independent surgeon. CONCLUSIONS: This article defines the key structural, administrative, and executive principles for CTS training. Programmes are encouraged to review and modify their training curricula, if necessary, to ensure the delivery of high-quality, standardized, outcome-orientated CTS training across Europe.

Supravalvular aortic stenosis repair: surgical training of 2 repair techniques using 3D-printed models.

There are a number of techniques used in the surgical treatment of supravalvular aortic stenosis with excellent results; however, junior surgeons' experience may be limited due to its rare nature. Simulation with 3D-printed models provides a safe platform for surgeons to rehearse surgical techniques prior to patient application but must replicate all features of surgical anatomy. Here, we describe how software manipulation can be used to accurately reproduce the surgical anatomy in supravalvular aortic stenosis and be used to train surgeons in 2 different techniques.

Evaluating the Impact of Medical Student Inclusion Into Hands-On Surgical Simulation in Congenital Heart Surgery.

OBJECTIVE: Over the last decade medical students' interest in pursuing surgery as a career has declined. This is more apparent in high-specialized specialities such as congenital heart surgery (CHS). Early hands-on simulation has shown to have a positive impact on medical students' interest in pursuing surgery, however, its incorporation into medical school curricula is lacking. This study aimed to evaluate the impact of incorporating medical students as surgical assistants during the Hands On Surgical Training course in CHS. METHODS: Local preclinical medical students were invited to participate as surgical assistants during the 5th annual Hands On Surgical Training course in CHS. Among those who responded to the invitation, students were randomly selected and allocated to assist a congenital heart surgeon. All selected students attended an assistants' session prior to the course to familiarize themselves with assisting and to practice basic surgical skills. At the end of both courses students completed a questionnaire based on Likert 5-point scale to evaluate the courses' usefulness. RESULTS: Fifteen medical students completed the questionnaires. All reported a beginner level of understanding of congenital heart disease. All students were highly satisfied with using 3D-printed models to help their understanding of congenital heart disease (4.80 ± 0.41) and agreed that the sessions improved their assisting skills (4.93 ± 0.26). All expressed a desire to attend similar sessions in the future and agreed that surgical simulation inclusion into medical school curricula would enhance learning (5.00 ± 0.00). Interest in pursuing a career in CHS increased from 33% (5) to 87% (13) by the end of the course. CONCLUSIONS: Integration of preclinical medical students into surgical simulation increases interest in pursuing highly specialised surgical specialities such as CHS. Early exposure and the incorporation of such simulation programs into medical school curricula will likely improve surgical skill acquisition and may enable students to be better informed when selecting future career choices.

The Incorporation of Hands-On Surgical Training in a Congenital Heart Surgery Training Curriculum.

BACKGROUND: The monthly in-house Hands-On Surgical Training (HOST) program was incorporated into the congenital heart surgery (CHS) curriculum for surgical trainees within our institution. This study evaluated whether there was an improvement and retention of technical skills throughout the curriculum via objective assessment methods. METHODS: Twelve 3-dimensional-printed surgical heart models were included into the year-long curriculum. The monthly sessions were attended by all trainees and staff surgeons. Proctors demonstrated the operation on a model, which was followed by 2 attempts by each trainee. Attempts were recorded for objective assessment. On completion of the curriculum trainees repeated 4 procedures an additional 2 times after a delay to assess skill retention. RESULTS: Twelve sessions were completed by 7 trainees within the curriculum. Objective assessments were performed in 7 sessions. Eighty-one percent of trainees' scores improved between the 2 attempts, with a mean improvement of 13% (attempt 1: HOST-CHS score of 79, attempt 2: HOST-CHS score of 89; P < .001). Similarly, 91% of procedural times improved by a mean of 25% (attempt 1, 1:22:00 [hours:minutes:seconds]; attempt 2, 1:01:21; P < .001). During individual procedure analysis, statistical significance remained in 3 of 7 procedures (P < .05). Four procedures were assessed for skill retention after a delay (2-14 months). Scores decreased by 4% in 47% of trainees during attempt 3 (attempt 2: HOST-CHS score of 94, attempt 3: HOST-CHS score of 91; P = .34) but improved in 79% during attempt 4 (attempt 3: HOST-CHS score of 91, attempt 4: HOST-CHS score of 99; P = .004), matching their previous performance. CONCLUSIONS: The monthly HOST course was successfully incorporated into a training curriculum for CHS surgeons using objective assessments to measure technical performance. Trainees demonstrated an improvement across all evaluated procedures and retained their skills when reassessed after a delay highlighting its value in CHS training.

Tricuspid Valve Intervention at the Time of Pulmonary Valve Replacement in Adults With Congenital Heart Disease: A Systematic Review and Meta-Analysis.

Background Tricuspid regurgitation (TR) is a common finding in adults with congenital heart disease referred for pulmonary valve replacement (PVR). However, indications for combined valve surgery remain controversial. This study aimed to evaluate early results of concomitant tricuspid valve intervention (TVI) at the time of PVR. Methods and Results Observational studies comparing TVI+PVR and isolated PVR were identified by a systematic search of published research. Random-effects meta-analysis was performed, comparing outcomes between the 2 groups. Six studies involving 749 patients (TVI+PVR, 278 patients; PVR, 471 patients) met the eligibility criteria. In the pooled analysis, both TVI+PVR and PVR reduced TR grade, pulmonary regurgitation grade, right ventricular end-diastolic volume, and right ventricular end-systolic volumes. TVI+PVR, but not PVR, was associated with a decrease in tricuspid valve annulus size (mean difference, -6.43 mm, 95% CI, -10.59 to -2.27; P=0.010). Furthermore, TVI+PVR was associated with a larger reduction in TR grade compared with PVR (mean difference, -0.40; 95% CI, -0.75 to -0.05; P=0.031). No evidence could be established for an effect of either treatment on right ventricular ejection fraction or echocardiographic assessment of right ventricular dilatation and dysfunction. There was no evidence for a difference in hospital mortality or reoperation for TR. Conclusions While both strategies are effective in reducing TR and right ventricular volumes, routine TVI+PVR can reduce TR grade to a larger extent than isolated PVR. Further studies are needed to identify the subgroups of patients who might benefit most from combined valve surgery.

Transcatheter valve-in-valve implantation for degenerated bioprosthetic aortic and mitral valves - an update on indications, techniques, and clinical results.

Introduction: Aortic and mitral bioprosthesis are the gold standard treatment to replace a pathological native valve. However, bioprostheses are prone to structural valve degeneration, resulting in limited long-term durability. During the past decade, the implantation of transcatheter stent-valves within degenerated aortic and mitral bioprostheses, (the so-called 'valve-in-valve' procedure), represents a valid alternative to redo surgery in patients with high-risk surgical profiles.Areas covered: We reviewed the clinical outcomes and the procedural details of transcatheter aortic and mitral valve-in-valve series according to current published literature and include a practical guide for valve sizing and stent-valve positioning and strategies to prevent complications.Expert opinion: In both aortic and mitral positions meticulous planning is fundamental in these procedures to avoid serious complications including patient prosthesis mismatch, coronary obstruction and left ventricular outflow tract obstruction.

3D Modeling and Printing in Congenital Heart Surgery: Entering the Stage of Maturation.

3D printing allows the most realistic perception of the surgical anatomy of congenital heart diseases without the requirement of physical devices such as a computer screen or virtual headset. It is useful for surgical decision making and simulation, hands-on surgical training (HOST) and cardiovascular morphology teaching. 3D-printed models allow easy understanding of surgical morphology and preoperative surgical simulation. The most common indications for its clinical use include complex forms of double outlet right ventricle and transposition of the great arteries, anomalous systemic and pulmonary venous connections, and heterotaxy. Its utility in congenital heart surgery is indisputable, although it is hard to "scientifically" prove the impact of its use in surgery because of many confounding factors that contribute to the surgical outcome. 3D-printed models are valuable resources for morphology teaching. Educational models can be produced for almost all different variations of congenital heart diseases, and replicated in any number. HOST using 3D-printed models enables efficient education of surgeons in-training. Implementation of the HOST courses in congenital heart surgical training programs is not an option but an absolute necessity. In conclusion, 3D printing is entering the stage of maturation in its use for congenital heart surgery. It is now time for imagers and surgeons to find how to effectively utilize 3D printing and how to improve the quality of the products for improved patient outcomes and impact of education and training.

Development of a dynamic Chest Wall and operating table simulator to enhance congenital heart surgery simulation.

BACKGROUND: The Hands-On Surgical Training in Congenital Heart Surgery (HOST-CHS) program using 3D printed heart models has received positive feedback from attendees. However, improvements were necessary in the simulator set up to replicate the ergonomics experienced in the operating room. This paper illustrates the development of a dynamic chest wall and operating table simulator to enhance the simulation experience. METHODS: The simulator was designed to address the limitations with the existing set up. This included a suboptimal operating position, unrealistic surgical exposure and limitations in illuminating the operative field and recording procedures. A combination of computer-aided design and various 3D-printing techniques were used to build the components. The simulator's usefulness was evaluated by surgeons who attended the 5th annual HOST course via a questionnaire. RESULTS: The simulator consists of three components; an operating table simulator which allows height adjustment and pitch-and-roll motion; a suture retraction disc, which holds sutures under tension to improve exposure; and a pediatric chest wall cavity to replicate a surgeon's access experience during surgery. Nineteen surgeons completed the questionnaire. All surgeons agreed that the addition of the simulator was acceptable for surgical simulation and that it helped replicate the ergonomics experienced in the operating room. CONCLUSIONS: The inclusion of the HOST-CHS simulator adds value to simulation in congenital heart surgery (CHS) as it replicates the view and exposure a surgeon experiences. Improvements like these will help develop high-fidelity simulation programs in CHS, which could be utilized to train surgeons globally.

Simulation of semilunar valve function: computer-aided design, 3D printing and flow assessment with MR.

BACKGROUND: The structure of the valve leaflets and sinuses are crucial in supporting the proper function of the semilunar valve and ensuring leaflet durability. Therefore, an enhanced understanding of the structural characteristics of the semilunar valves is fundamental to the evaluation and staging of semilunar valve pathology, as well as the development of prosthetic or bioprosthetic valves. This paper illustrates the process of combining computer-aided design (CAD), 3D printing and flow assessment with 4-dimensional flow magnetic resonance imaging (MRI) to provide detailed assessment of the structural and hemodynamic characteristics of the normal semilunar valve. METHODS: Previously published geometric data on the aortic valve was used to model the 'normal' tricuspid aortic valve with a CAD software package and 3D printed. An MRI compatible flow pump with the capacity to mimic physiological flows was connected to the phantom. A peak flow rate of 100 mL/s and heart rate of 60 beats per minute were used. MRI measurements included cine imaging, 2D and 4D phase-contrast imaging to assess valve motion, flow velocity and complex flow patterns. RESULTS: Cine MRI data showed normal valve function and competency throughout the cardiac cycle in the 3D-printed phantom. Quantitative analysis of 4D Flow data showed net flow through 2D planes proximal and distal to the valve were very consistent (26.03 mL/s and 26.09 mL/s, respectively). Measurements of net flow value agreed closely with the flow waveform provided to the pump (27.74 mL/s), confirming 4D flow acquisition in relation to the pump output. Peak flow values proximal and distal to the valve were 78.4 mL/s and 63.3 mL/s, respectively. Particle traces of flow from 4D-phase contrast MRI data demonstrated flow through the valve into the ascending aorta and vortices within the aortic sinuses, which are expected during ventricular diastole. CONCLUSION: In this proof of concept study, we have demonstrated the ability to generate physiological 3D-printed aortic valve phantoms and evaluate their function with cine- and 4D Flow MRI. This technology can work synergistically with promising tissue engineering research to develop optimal aortic valve replacements, which closely reproduces the complex function of the normal aortic valve.