Of the many developments in cardiothoracic surgery, the introduction of a broad spectrum of simulation techniques for education and training of students and residents as well as ongoing faculty training are among the most exciting and critical for the continued advancement of the specialty. There are increasing demands for safety during training, for training to be more effective and efficient, and have minimal impact on the process of patient care. The productivity of training for physicians has advanced in many ways; simulation is one approach to teaching that offers solutions to challenges in training in general and especially in cardiac surgery. In this chapter, we describe a spectrum of simulation technologies and techniques that are being applied to address these challenges. We also address approaches to using simulation to its greatest effect and speculate about future technologies and applications and how they will be integrated into education at all levels of experience.

Simulation has been described as a “technique, not a technology, to replace or guide real experiences with guided experiences that evoke or replicate substantial aspects of the real world in a fully interactive manner.”¹ The roots of simulation in medicine can be traced back for centuries. More recent applications in the 1960s and 1970s for training in specific tasks include the Sim One for teaching in anesthesia residency, Resusci Anne for training in cardiac life support, and Harvey for teaching about cardiology to medical students.² The more modern era of simulation began in earnest in the late 1980s with the development of more realistic mannequins for teaching basic skills and management of crises in anesthesia. Surgeons have long used various forms of simulation, from tying knots on paperclips placed in clay to cadavers and animals. The first use of a model simulator was introduced by Howard in 1868 in which a mannequin was created to teach hernia repair.³ But, more technology-based forms of task trainers for various surgical and procedural skills appeared beginning in the late 1980s.²

For many reasons, the use of simulation is growing in all of healthcare, and specifically in cardiac surgery. Ziv and colleagues described the adoption of simulation in surgical training as an ethical imperative noting patient safety as their cause.⁴ With patients having increased acuity, practicing outside of the operating room is critical for mastering tasks to quickly develop critical skills without exposing patients to increased risk. Practice via simulation has been shown to increase speed for completion of coronary anastomosis⁵ as well as increase speed and accuracy of mitral valve annuloplasty.⁶ Through deliberate practice (rehearsing a task or behavior repeatedly), simulation provides the ability to advance the mastery of some skills more quickly, reducing operating time related to training. Simulation is also the preferred modality to improve teamwork and communication and to practice emergencies not frequently seen during training. It enables surgeons and teams to work out complex problems in a nonthreatening setting and apply the lessons to urgent and emergent situations.

Surgical simulation may provide an important modality for measuring proficiency for certification, recertification, or for judging appropriateness of clinical advancement within a training program. For example, a particular task such as anastomosis of one small vessel to another has many components that can be evaluated for simple tasks such as instrument use, suture handling, and tissue handling. The same tasks can be integrated into a more complex scenario on a higher fidelity simulator; for example, rather than sewing a simple anastomosis, anastomoses may be incorporated into a beating-heart coronary artery bypass graft (CABG) on the simulator. Graft measurement, appropriateness of anastamotic site, vessel opening, and preparation can be evaluated. In addition, these tasks can be incorporated into the entire bypass procedure for more advanced learning as training progresses.

Simulation education has gained significant traction in cardiac anesthesia training as well. Bruppacher and colleagues performed a randomized controlled trial in which anesthesia residents were randomized to simulation training and no simulation training for cardiopulmonary bypass weaning.⁷ The residents were evaluated using an internally validated scoring system administered by blinded attending anesthesiologists before and after simulation training. The residents who underwent two hours of simulation training improved significantly more than the residents who underwent two hours of didactic instruction.

The most exciting advancement in cardiac surgical simulation training occurred in 2005 when Ramphal created a relatively high realism porcine beating-heart model to address the shortage of cardiac surgery cases being afforded to residents in training in Jamaica⁸ (Figs. 8-1 and 8-2). The simulator was adapted by a leadership group in cardiothoracic surgery in the United States and incorporated into focused programs to advance simulation-based learning. The Thoracic Surgery Foundation for Research and Education’s (TSFRE) annual Boot Camp conference and “Senior Tour” are sponsored by the Thoracic Surgery Directors’ Association and the American Board of Thoracic Surgery and the Joint Counsel on Thoracic Surgical Education (JTSE).⁹ The three-day, well-orchestrated simulation curriculum has been conducted since 2008 and provides focused learning for first-year cardiothoracic residents with feedback and standardized evaluations. Standardized evaluation of first-year residents participating in the “Boot Camp” consistently show improvement in time to complete basic cardiothoracic techniques as well as accuracy.^10,11

Creating a successful cardiac simulation program requires understanding and application of the principles of adult learning. In 1993, Reznick^12,13 described the process of adults learning surgery and the relationship between the trainee and expert instructor. He referenced key educational literature describing Kopta’s three stages of adult learning, perception, integration, and automatation¹⁴ as well as Collins’ framework for the apprenticeship model characterizing the roles the teacher plays as the student progresses from novice to expert.¹⁵ Those principles are applied to how we approach simulation-based training in all aspects. We next present the current state of how this is done for training in basic skills, what specific procedures currently can be simulated, and what existing simulators are available for cardiac and thoracic surgery.

For cardiothoracic surgery, simulation training begins with teaching of component tasks, starting at the most basic level and combining those into multiple tasks and then full procedures. A consortium of six hospitals (Massachusetts General Hospital, University of North Carolina Chapel Hill, Johns Hopkins, University of Rochester, Stanford University, Vanderbilt University, and University of Washington) developed a 7-week syllabus, broken down into multiple key concepts and procedures consisting of cardiopulmonary bypass (Fig. 8-3), CABG (Figs. 8-4 to 8-7), valve replacement (Figs. 8-8 to 8-10), air embolism, and acute intraoperative aortic dissection (Fig. 8-11). First, fundamentals of cardiopulmonary bypass are taught step by step, including cannulation of the aorta, right atrium, and cardioplegia perfusion with repetitive practice on a perfused porcine heart. Concomitant with learning the technical aspects of these tasks is a memorization and understanding of the concept of initiating and weaning from cardiopulmonary bypass. The component tasks are then combined with the knowledge base on a higher fidelity model after practicing on the dry porcine heart. The student then integrates these steps using a beating-heart model to fully cannulate, institute bypass, arrest the heart, wean from bypass, and decannulate. The trainee is assessed in a standardized fashion by the expert instructor. The same process of moving from simpler tasks with low-fidelity models to more sophisticated and integrated tasks on higher fidelity simulators is conducted for the five components of the curriculum.

Deliberate practice prepares trainees to apply the basic principles of cardiac surgery to more complicated groupings of tasks. In the CABG component of the curriculum, the resident performs large and small vessel anastomoses, first on a component simulator and later on a porcine heart. The trainee will later combine the steps to perform a full coronary bypass operation on the beating-heart simulator. This process is repeated with the basics of aortic valve surgery. That training begins by teaching the resident about the anatomy of the aortic valve and root and exposing it in the anatomic dissection on the porcine heart. The resident will next practice excising the valve, placing sutures in the annulus repetitively, ultimately seating and tying in all different types of valves until they become proficient. Once this task is mastered, it is incorporated with the previously mastered bypass skills to perform an aortic valve replacement on the beating-heart simulator.

In a similar fashion, mitral valve surgery can be learned. After these basic techniques have been practiced repeatedly, more advanced teaching that incorporates team training and dealing with emergencies can be simulated.

The training via simulation can include creating a plan, implementing that plan with the team in a dry model, and then carrying it out on the beating heart simulator. As noted above, specific emergencies that have been vetted on a simulator include managing aortic dissection at the cannulation site, managing massive air embolism and problems that can occur when weaning off cardiopulmonary bypass, for example, right heart failure, kinked or twisted grafts that can be too long or too short, leaks around the valve, and aortic root dissection. Simulation training is reaching beyond OR-based procedures to bedside invasive resuscitation and surgery.

In cardiac surgery, research has demonstrated that a model neck-cannulation trainer can improve trainee’s ability to cannulate the neck vessels for extracorporeal membranous oxygenation (ECMO) resuscitation.¹⁶ Chan and colleagues used a similar model but included a full pediatric intensive care unit (PICU) team in their ECMO training and evaluation.¹⁷ These were not evaluated by assessing participants’ skills during the cannulation of a live patient, however. Simulation is also being used to train perfusionists. Morris and Pybus describe a simulated (Orpheus) perfusion machine that can be used for training in the operating room or in a simulation center.¹⁸ Lansdowne and colleagues describe using the same simulator for training perfusionists and respiratory therapists on ECMO management.¹⁹ A new, exciting, and different use of simulation is 3-D printing for operative planning.^20–22 Valverde and colleagues used magnetic resonance imaging (MRI) and angiography to design a 3-D-printed model to plan endovascular stenting of an aortic arch coarctation in a 15-year-old boy.²³ Costello and colleagues even used 3-D printing as an educational model to train residents on ventricular septal defect (VSD) repair.²⁴

Trainees can also be led to assimilate hemodynamic information and practice communication skills with other personnel, including anesthesiologists, perfusionists, and nurses. While basic skills can be taught in a laboratory setting, teamwork skills can be taught in a high-realism operating room setting. This multimodal approach, with the gradation from low technology to high fidelity makes a rich environment not only for teaching but also for performance evaluation (see below).