Advancing IR in Underserved Regions: Interventional Radiology Simulation Near and Far

Abstract

Simulation facilitates learning by imitating real-world systems or processes utilizing educational tools and models. Various fields, including business, aviation, and education use simulation for training. In healthcare, simulation provides trainees opportunities to develop procedural skills in a safe environment, building their understanding through hands-on interactions and experiences rather than passive didactics. Simulation is classified into low, medium, and high fidelity, based on how closely it mimics real-life experience. Its use in education is a valuable adjunct to instructional support and training with multiple potential benefits. Interventional radiology (IR) trainees can build technical and clinical proficiency prior to working directly on a patient. Simulation promotes experiential learning, constructivist learning, and student centeredness, thus giving students control over their learning and knowledge acquisition. More recently, the creative use of remote simulation has augmented traditional virtual didactic lectures, thereby further engaging international learners and enhancing remote collaboration. Despite the challenges to implementation, the addition of simulation in IR education is proving invaluable to supporting trainees and physicians in underserved regions.

History of Simulation

Simulation is the practice of imitating real-world systems or processes for the purpose of research or training. ¹ Thinking broadly, simulation in medicine dates back thousands of years, with the use of clay livers in Babylonia in 1900 to 1600 BC and Aristotle's advice to develop expertise through repetition and training models. ² More recently, the aerospace industry championed simulation use with the introduction of Edward Link's “Blue Box” flight simulator in 1929. While sales of this basic simulator lagged initially, it went on to become highly coveted in World War II, reducing Air Force pilot deaths by 90%. ³ Digital simulation dates back to the Second World War when Stanislaw Ulam and Jon Von Neumann modeled nuclear detonation designs using newly developed computing techniques. ^{4 5} The success of these mathematicians' experiments led to the rapid adoption of simulation in the aviation, business, fire safety, and education industries. In healthcare, medical simulations have evolved to support and enhance traditional curricula. ^{1 6} The Society for Simulation in Healthcare (SSH), established in 2002, promotes the application and integration of simulation in healthcare. Challenging the traditional, apprenticeship model of medical education, in which trainees work under the supervision and tutelage of an attending physician, simulation allows practice without exposing patients to harm. The intrinsic tension between the ethical imperative of prioritizing patient welfare and promoting trainee education was the focus of Atul Gawande's 2002 essay, “The Learning Curve,” where he wrote, “We want perfection without practice. But everyone is harmed if no one is trained for the future.” ⁷

Simulation provides an alternative pathway to safely train healthcare professionals for the future. The literature evaluating simulation in medical education has centered on “in-person” or “on-campus” trainee education. However, the potential applications for simulation in educating trainees who live in separate or remote locations has yet to be fully explored. This article examines the available literature and history of simulation in medical education, its applications in interventional radiology (IR), and suggests avenues for future implementation, utilization, and research.

Introduction to Endovascular Simulation

Endovascular simulation uses patient models to replicate endovascular procedural techniques in a controlled and reproducible environment. Simulation in endovascular work represents a unique challenge, as these procedures require highly specialized equipment with varying degrees of tactile and visual feedback; for example, the use of a catheter and guidewire to cannulate a renal artery under fluoroscopic guidance. Real-world IR trainee experiences vary greatly, as the types and number of cases performed at the trainee's institution are based on the division's practice and referral patterns. The diversity of institutional practices means that trainees could potentially never see certain procedures or pathologies that they may be asked to manage in the future. For example, peripheral angiography and vascular interventions may be performed by vascular surgeons or cardiologists, depending on the hospital and regional practice patterns. Simulation can, in part, help fill some of these gaps in their training.

To address these problems, both low-fidelity and high-fidelity simulators have been developed. The term “fidelity” in this context describes how closely a simulator reflects real clinical experiences. Low-fidelity simulators have limited flexibility and can only meet a few requirements for practicing skills; however, they carry the added benefit of increased accessibility and affordability. High-fidelity simulators more accurately replicate complex clinical situations and can provide contemporaneous feedback to better mimic clinical scenarios. However, as the complexity of the simulation increases, so do the costs and, ironically, the learning curve of handling the simulation. The most appropriate fidelity level depends on the complexity of the task and the skill level the user intends to achieve. ⁸

High-fidelity devices simulate endovascular work, including manipulation of catheters and guidewires, angioplasty, embolization, and the deployment of stents. ⁸ These simulators are designed to enhance users' experience by providing tactile, visual, auditory, formative, and summative feedback. Formative feedback is the on-going evaluation provided during the simulation sessions by way of interactive question–answer sessions. Summative feedback is typically provided at the end of the training sessions or end of a course or semester.

Types of Simulation

Low-Fidelity Simulation

There is a long history of low-fidelity simulation use in medical education. An historic and popular example is the use of pig skin to mimic human skin in the practice of suturing. ^{9 10} The role of low-fidelity simulation in endovascular training is limited due to the intrinsic complexity of endovascular work. Low-fidelity simulation could never replicate angiography and embolization of a malignant hepatic lesion. This is not to say that low-fidelity simulation has no role in the training of an interventional radiologist. Numerous procedures and skills can be practiced using low-fidelity models, such as ultrasound guidance, percutaneous access, biopsy, and catheter exchange. May et al described a variety of low-fidelity models, including a gelatin-based mold containing a Penrose drain which is filled with colored water. ¹¹ The product is a low-cost, low-fidelity simulation of a vessel that can be used for percutaneous access simulation. Another example is a water-filled surgical glove as a simulacrum of a dilated pelvicalyceal collecting system for teaching ultrasound-guided nephrostomy tube access. ¹¹ While these low-fidelity simulators may not train residents on the interpretation and use of real-time fluoroscopy for endovascular procedures, the skills tested (e.g., catheter manipulation, hand–eye coordination, and needle technique) are indispensable for any interventionalist. Data have shown that training radiology residents in ultrasound-guided procedures on low-fidelity mannequins resulted in significant improvement in knowledge and technical competence. ¹²

Many institutions employ “boot camps” or focused simulation sessions for residents and medical students early in their IR rotation, using low-fidelity simulation to prepare them for bread-and-butter IR cases. Low-fidelity simulation models are readily available, can be made at home and transported to the lab, and are relatively inexpensive to produce or purchase.

High-Fidelity Simulation

High-fidelity simulation utilizes more advanced technology to attain higher levels of visual and auditory realism to represent actual clinical settings more closely. “Validity” is a concept that helps characterize high-fidelity simulation using its three main components including face, content, and construct validity. Face validity assesses the simulator's ability to mimic real life, such as pig skin closely approximating human skin for the practice of suturing. Content validity describes how closely the steps that make up the simulation parallel the desired training objective. For example, placing a central line on a mannequin demonstrates high content validity, as the steps on a mannequin are identical to that of a human. Construct validity assesses the simulator's ability to discriminate between different expertise levels. Additional features of high-fidelity simulation include interactivity, individualized learning, feedback, and the ability to depict a range of clinical scenarios and pathologies using three-dimensional models and realistic interfaces. ⁸

High-fidelity simulation is thus ideal for training healthcare professionals in endovascular procedural techniques ( Fig. 1 ). Commercially available endovascular simulators include the ANGIO Mentor (Surgical Science/Simbionix, Gothenburg, Sweden) and the G5 and G7 VIST Simulators (Mentice, Gothenburg, Sweden). Using a high-fidelity trainer, Coates et al found that the device demonstrated high levels of construct validity and led to improved performance on tested procedures. ¹³ This allows trainees to focus on enhanced performance in a relatively stress-free environment. ⁸

Fig. 1.

High-fidelity simulation training using the Mentice simulator at the Division of Interventional Radiology, Department of Diagnostic Imaging and Radiation Medicine, University of Nairobi.

Simulation in Education

Benefits of Simulation Use in Education

Simulation in education is a valuable adjunct to instructional support and training. The primary objective is to improve trainee proficiency in the safety of a simulated environment with the expectation that simulated mastery will translate to clinical proficiency. This concept has been demonstrated across a variety of medical specialties. In interventional cardiology, there is evidence that simulator use is associated with improved angiography skills and decreased fluoroscopy time. ¹⁴ An intensive 1.5-day course combining low- and high-fidelity simulation was shown to increase procedural knowledge and self-rated competency in vascular surgery residents. ¹⁵ Virtual reality (VR) simulation in general surgery significantly improved performance in the operating room during laparoscopic cholecystectomy. ¹⁶ Urology residents demonstrated significant improvement in percutaneous renal collecting system access following training on a high-fidelity hybrid model compared to those without simulator experience. ¹⁷ Pulling from the literature in IR, Patel and Dennick found that training with simulators resulted in significantly improved resident abilities within simulated environments. ¹⁸ Finally, the use of simulated training for the placement of peripherally inserted central catheters (PICCs) resulted in improved resident abilities and patient-centered outcomes for PICC placement in oncology patients. ¹⁹ The consensus suggests that the repetitive and consistent use of simulators increases resident skills in simulated environments with evidence that this ultimately translates to improved clinical outcomes for patients.

Beyond improving trainee competency, there are numerous additional benefits to simulation use in medical education. Endovascular simulators improve procedural efficiency, device proficiency, and clinical workflow. ^{20 21} High-fidelity simulators can generate error reports and instantaneous feedback, helping to guide education and training. Compared to traditional teaching methods, simulation and VR allow medical knowledge, such as complex anatomy, to be presented in 3D, improving student attention, satisfaction, confidence, and motivation. ²² Following basic skills mastery, learners can dedicate more attention and cognitive energy to higher-order decision making. Borrowing from the American Board of Radiology's (ABR's) manual on noninterpretive skills (NIS), simulation encourages a shift from knowledge-based actions to skill-based actions. Simulator accessibility allows trainees to build a personalized curriculum better suited to their schedule. The use of simulation in medical student education provides students with early exposure to interventional procedures and promotes interest in interventional-oriented specialties. ^{23 24 25}

There is a pervasive assumption that high-fidelity simulation results in improved performance and better clinical outcomes compared to low-fidelity simulation, but this is not necessarily borne out by the evidence. Similarly, single-time use of high-fidelity simulation is not more effective when compared to other educational methods. ²⁶ There is evidence that certain skills can be learned using low-fidelity or high-fidelity simulation without differences in proficiency or affecting clinical outcomes. For example, no significant difference in clinical outcome (i.e., delayed patency) was found between 50 junior surgery residents practicing micro suturing on high-fidelity (anesthetized rat vas deferens) and low-fidelity (silicone tubing) models. ²⁷ Not unsurprisingly, 90% of participants preferred working with the high-fidelity model over the low-fidelity model and accordingly rated it higher in terms of educational value. While the authors did not determine why the trainees felt this way, it was presumed to be due to more engagement with the high-fidelity model. ²⁷ Similarly, a group of medical students who practiced advanced life support on high-fidelity and low-fidelity mannequins demonstrated no significant difference in theoretical knowledge or practical skills, although the group trained on the high-fidelity model rated themselves as more competent. The evidence suggests that any kind of simulator, regardless of fidelity level, improves trainee proficiency and comfort with the tasks being tested. ²⁸

In-Person Education Use

Traditional use of simulation for education requires the trainee to have in-person, hands-on interaction with the simulator. These modular experiences and interactions allow the trainee to be guided through initially challenging clinical scenarios and procedures. The experiential learning, constructivist learning, and student-centeredness provided through simulation gives students power over their learning and knowledge acquisition. In keeping with constructivist philosophy, simulation allows students to construct their knowledge and understanding through interactions and experiences. ²⁹ Trainees create their own reality and build upon their foundation of knowledge through the experience of simulated cases. Constructivist key principles include that knowledge is constructed based on prior knowledge and experiences, learning is an active process, learning is a social activity, and learning is contextual. ²⁹

Simulation and other forms of experiential learning challenge misconceptions among students and promote self-directed learning and critical thinking. Students enrolled in in-person simulation classes demonstrate better learning outcomes than those in lecture-only classes. ³⁰ Additionally, simulation-based learning allows trainees and students to collaborate and exchange knowledge and skills. In the clinical simulation, healthcare trainees learn effective communication, teamwork, and interpersonal skills for an enhanced experience in diverse clinical scenarios. A relationship between achievable competency levels and specific forms of simulation training has been described using Miller's pyramid framework of clinical competence. This assesses knowledge at the base to action at the top in a manner of ascending characteristics, from “knows” to “knows how” to “shows how” and finally to “does.” This requires most of the trainees to surpass the “shows how” category. ²⁸

For high-fidelity endovascular simulation use in IR, the trainee's ability to manipulate wires and catheters, visualize real-time guidance of this equipment, and fully engage mentally and physically in the module is essential. For maximal benefit, the trainee should have consistent access to the simulation unit for repetition and opportunities to improve on prior performance and shortcomings.

In addition, simulation promotes international cooperation as exemplified by the work of Rad-Aid International. Through their volunteer network, they provide collaborative faculty support, remote training sessions, scheduled in-person visits, and other technical support to programs looking to advance in-country radiology services and training. The short-term outcomes for the learners in Kenya at the University of Nairobi suggest that the Mentice high-fidelity simulator has enhanced the IR fellows' technical skills with a variety of vascular procedures. The fellows report reduced procedure times and increased confidence performing procedures such as uterine artery embolization, liver embolization, and trauma embolization. The endovascular simulator is housed within the Department of Radiology, near the IR procedure rooms. This allows easy access for the trainees at times that are convenient for them. The simulator provides immediate visual and tactile feedback during use and summative feedback at the conclusion of each session regarding fluoroscopic time and other metrics. Anecdotally, this has exposed new fellow trainees to a variety of endovascular interventional procedures. The simulator functions as a platform for mentors and learners to engage in knowledge and skill-set transfer during the practice sessions ( Fig. 2 ). The arrival of the simulator in Nairobi means that distance is no longer an obstacle for trainees who are seeking additional educational opportunities in IR.

Fig. 2.

Dr. Robert Dixon leads a group of residents and fellows at the University of Nairobi through a module using the high-fidelity Mentice simulator.

Remote Education Use

Rapidly evolving technology, simulation tools, and software allow for new advances in remote education and training. These innovative methodologies make these experiences accessible to learners from different geographical regions. A proof-of-concept project utilizing cost-effective VR equipment showed that virtual clinical simulation can facilitate interactive training and global education networking between resource-rich and underserved regions. ³¹ Improved student presence (degree of experiencing reality or perceived sense of being there) within a remote virtual simulation experience has also been described. ³² Remote virtual simulation also has the potential to enhance higher cognitive processes including decision making and problem solving while experiencing new and challenging scenarios which allow for self-evaluation. ³³ Remote VR simulation and video-enabled simulation have proven to be effective platforms for disseminating knowledge and improving clinical skills for fire safety incident commanders and critical care providers in diverse international settings. ^{32 33 34}

Recent data regarding remote learning come from the COVID-19 pandemic era, during which many educators needed to develop new methods of teaching while separated by considerable distance from their pupils. Within diagnostic radiology, the pandemic had a significant impact on resident education, with both diagnostic and interventional caseloads decreasing precipitously in April 2020 as compared to the previous 5 years. ³⁵ This study demonstrated the urgent need to restructure the current training model, anticipate that future disruptive events could again result in an increased need for remote learning, and to adopt these creative solutions for in-person teaching. ³⁵ VR use during a 2-week undergraduate diagnostic radiology elective found mixed results, with students performing better at limited tasks in part due to underlying technical challenges. ³⁶ A separate group developed a VR training system using an endovascular robotic system; this may one day represent how IR is practiced, but it is limited to particular academic centers and is still very much a nascent technology. ³⁷ Hayden et al described “telesimulation,” in which the instructor observes via webcam and remotely controls a mannequin being used to simulate a variety of cases. This likely represents a more technologically feasible model for remote simulation, but still requires a robust information technology (IT) infrastructure. ³⁸

The COVID pandemic limited the in-country presence at the University of Nairobi, forcing the RAD-AID IR team to switch to didactic teaching online. The virtual didactic talks were augmented with remote simulation sessions ( Fig. 3 ). These forums were truly engaging for the participants and allowed a relaxed and interactive session, presented by multiple instructors. These sessions connected learners in Nairobi, Kenya, with teachers located in three different cities within the United States. Initially, a short, 10-minute didactic session was given to provide an overview of the topic. Then, one instructor operated the simulator with audio–video feed of the operator as well as live images from the simulator's angiography display, while two other presenters provided commentary and asked the audience and the instructors questions. In addition, questions generated by the attendees were also addressed. This arrangement allowed for a very lively, interactive meeting, requiring instructor and attendees to stay sharp as unexpected events could occur, such as the inability to access a distal vessel and questions coming from all angles.

Fig. 3.

A remote simulation session using the high-fidelity Mentice simulator was performed by RAD-AID IR as a U.S.-based physician walked through cases being broadcast to international learners.

As this technology matures, remote simulation could be used for oral exams, with the examinee performing a procedure while discussing their decision process, choice of tools, success rates, and complications. In addition, if the ability to sync distant simulators comes to fruition, an interventionalist in one location could remotely operate a simulator in another location.

Challenges and Limitations of Simulation Use in Education

Despite the promise of simulation, there are various limitations to its widespread adoption and utilization. The main limitation to its use in education is cost. The cost of high-fidelity simulation is quite high, in part because of the need for sufficient computational power, realistic haptic and visual interfaces, and quality graphics, and this hinders its widespread utilization. ⁸ In a radiology elective for undergraduate students, Wu et al cited the cost of a high-fidelity VR workstation as $3,200 CAD and the software license as $600 CAD. ³⁶ Another study found the cost per trainee to practice microsurgical techniques on a high fidelity, live rat vas deferens model was $55 CAD, while it was only $1.50 CAD for the low-fidelity, silicone tubing model. ²⁷ Despite this cost difference, long-term patency rates were the same across both groups. This suggests that while simulation gains a foothold in the standard curricula for radiology residents, low-fidelity models will likely be prioritized for their ease of acquisition and relative cost-effectiveness until high-fidelity models become more accessible. As the use of simulation in medical education continues to expand, one must consider how to best implement such strategies in the setting of finite resources.

Secondly, simulation equipment is sophisticated and may require specialized training for optimal utilization. Initial training will need to be provided by the device representative before being passed along from skilled to new users. Thirdly, most simulation devices require adequate space and personnel for maintenance; it may prove challenging for centers to physically accommodate the equipment in their department. Lastly, some forms of simulation feedback may not accurately reflect the level of skill or learning acquired due to low levels of fidelity and the inability to accurately mimic real-world scenarios. Despite these limitations and the challenges associated with its use in education, simulation increases procedural efficiency and cost savings and reduces adverse events. ³⁹

Some have argued that the relative paucity of objective evidence supporting simulation training in IR is limiting its broad implementation. ²⁴ While there are intuitive benefits to using simulation to augment trainee education and some studies have demonstrated improved trainee competency with the repeated use of simulators, there has been less data demonstrating improved patient outcomes. ^{13 40} There is even less data regarding how efficacious simulation is in a remote setting. Until these data are better understood, there is unclear consensus regarding best practices for integrating simulation in a medical trainee curriculum. The challenges described earlier can be effectively mitigated by demonstrating the benefits of simulation training for procedure-related variables, clinical patient outcomes, as well as learner-focused outcomes in the local and remote setting.

Conclusion

Simulation in medical education has been widely used for instructional support in both in-person and remote education. A variety of models allow learners to study simulated events in various contexts. There is now potential to expand, reimagine, and standardize the education of IR trainees throughout the world.

Healthcare trainees, especially those in IR and other procedural specialties, can hone their technical skills in simulated settings before they practice in real-life situations. This can help fill gaps in procedural skills, given the diverse practice patterns in underserved regions, allowing IR trainees to experience cases not seen clinically during their education.

Although simulation use in medical education enriches the learning experience, it is also associated with multiple challenges and limitations that may hinder its more widespread implementation and utilization. Efforts to demonstrate improved proficiency, efficiency, and patient outcomes through the use of simulation would help overcome these challenges.