Extensive experience is required to insert a catheter and guide it to the blood vessels of the heart or brain. Training models now offer physicians the opportunity to gain this experience in a safe environment. Using new 3D printing technologies, Charité-based researchers developed a new training model which is specifically aimed at radiology trainees. All relevant techniques can now be practiced using the Angio Trainer, which means that animal-based training models have become redundant.
Angiology, radiology and cardiology specialists all need outstanding technical and motor skills to safely guide catheters into the narrowest of blood vessels. Using catheter-based interventions, these specialists can dissolve blood clots in the brains of stroke patients, widen narrowed coronary arteries and treat liver cancer.
These immensely difficult procedures require a certain level of natural dexterity and fine motor skills. Mastering them, however, requires something more: practice, practice, practice. Traditionally, specialists-in-training used animal-based models (e.g. pigs) when learning to manipulate catheters and stents before being permitted to use their skills – under close supervision – on real patients.
Scarcity of easy cases makes training difficult
Beginners face a real challenge: The level of experience a trainee can gain using an animal model is limited, primarily because the overall time spent training is relatively short; add to this the fact that ‘easy’ real-life patient cases are now exceedingly rare. Improvements in modern imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) mean that catheters are now rarely used for purely diagnostic purposes. In most cases, they are used for combined diagnostic and treatment interventions. This development has resulted in a dearth of easy cases which would be suitable for training purposes.
“This lack of time spent training and gaining experience is a real problem,” opines PD Dr. Michael Scheel of Charité’s Institute of Neuroradiology. Four years ago, he used start-up funding to develop a simulator which can be used by students and residency trainees to learn the fundamentals of endovascular therapies. The model was produced by a 3D printer. “To some extent, the Anglo Trainer was an innovation born out of necessity, because as far as I see it, there is plenty of room for improvement in current training programs,” explains Michael Scheel. He adds: “Models remain underused as training tools. I also happen to think that pigs do not make particularly good training models. Aside from the obvious ethical implications, there are also major anatomical differences between pigs and humans, especially in the blood vessels of the head and neck. “”
A simulator with a heart
The Anglo Trainer is a much better representation of the human anatomy. The current 3D model comprises a life-like vascular system with in-built areas of severe narrowing and even a ‘heart’, which pumps water in order to maintain ‘blood supply’. The simulator can be adapted by adding other ‘organs’, such as the liver.
“Naturally, our model is limited in its level of realism. However, for the teaching of fundamental skills, it is a far more suitable model than either a pig or a severely ill patient,” says Michael Scheel. Training sessions can be as long as desired and can be delivered at any place and at any time. “Trainees can repeat procedures ad infinitum, until it finally clicks. This makes for a far better learning atmosphere,” posits the scientist. The model is also extremely robust, does not break and, at under €5,000, is reasonably priced.
Improved learning outcomes without animal suffering
There is, of course, another major benefit, namely that mistakes are not merely permitted, but encouraged. “We positively encourage users to make mistakes, so that they develop a sense of, and appreciation for, potential consequences,” says Michael Scheel, adding: “The learning effect is remarkable.” The Anglo Trainer is aimed at (future) physicians who are handling a catheter for the first time. How does one insert this thin tube into a blood vessel? How does one proceed when encountering a narrowed area? How does one place a stent in those areas? The simulator provides the ideal environment for learning these initial steps. As the simulator’s blood vessels are both transparent and freely accessible, trainees are able to study their own performance in a life-sized model. No animal model can provide this much access or insight.
Traditionally, porcine model-based training courses for residents last one weekend and are at a university hospital with an animal research focus. These courses provide limited time for experimentation, having to ensure that high numbers of participants get an opportunity to practice while the pigs being used for practice are kept under anesthesia and closely monitored. Given the obvious distress being caused to animals, this practice has also triggered an ethical debate. “While there is a long tradition of animal-based training courses, they are expensive and not very effective.” says the neuroradiologist. “I think that, sooner or later, we will be able to replace them with much more effective training models.”
“Plan to completely replace animal-based courses”
While the simulator does not yet form part of standard training, Scheel and his colleagues are determined to make it so. His current efforts include a drive to further promote and establish the Angio Trainer method across Charité, delivering training courses for external stakeholders, holding workshops and promoting the model at specialist conferences. The response has been extremely positive.
Explaining the motivation behind his efforts, he says: “My aim is to ensure that each department has one of these models.” He is optimistic for two reasons. Firstly, the learning outcomes are improved, and achieved at a lower cost, and secondly, there are further opportunities offered by new technologies. 3D printers will soon be capable of producing far more complex vascular systems. Scheel is convinced that additional refinement and detail will make the model more life-like. He also wants to encourage other colleagues to place greater emphasis on utilizing the opportunities offered by 3D printing. “Our model is an impressive example of how we can use 3D printing to produce alternatives to animal research,” he says. In this case, however, the purpose is not just to create another alternative to animal-based training courses. “The long-term goal is to replace them entirely.”
(Text: Beatrice Hamberger)
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