Editorial: See One, Do One, Teach One? Paradigm Shift with Three-Dimensional Printing

To the Editor: Most surgeons are familiar with the phrase “see one, do one, teach one.” This phrase embodies the concept of learning procedures by doing them. It fails to convey to trainees growing up in a system less than tolerant of mistakes and complications that the learning is “…on a person (the patient).” Despite oversimplifying the true nature of becoming a proceduralist, this mantra pervades all technical-based subspecialties. Patients who have entrusted their lives to surgeons and trainees have endured risks and complications as they knowingly—and sometimes unknowingly—serve as the practice model for physicians to learn and develop their knowledge and skills. With the use of simulators and increasing use of three-dimensional (3-D) printers, perhaps we can better train the next generation of surgeons with less risk conferred to patients. It has been more than 20 years since Satava1 suggested that virtual reality surgical simulation would change the paradigm in procedural training. Only a decade later, surgical simulation became popular for endovascular procedures such as carotid stenting;2 training under simulation has shown a marked objective improvement in acquiring the skillset to perform angiographic procedures safely.3-8 With the introduction of 3-D printing to the simulation world and related advances to perfect patient-specific models,9,10 the use of simulation, particularly 3-D-printed models, is becoming an integral tool to train budding proceduralists. From simple bedside procedures to stroke interventions, 3-D models are being utilized with increasing frequency to familiarize neophyte neurosurgeons with various procedures they may perform. With restrictions on work hours and supervision requirements for trainees, mastering procedures in an efficient manner has become difficult. Because of the time restraints on trainees and faculty, there is an increasing role for 3-D models. Such models have the consistency of human tissue without the potential for harm to patients. Three-D models for external ventricular drain placement providing realistic haptic feedback with simulation of the trajectory and placement of the catheter have been used in training.11 Similarly, highly accurate 3-D vascular phantoms (Figures 1A-1C) simulating the anatomy of complex intracranial vasculature have provided vast opportunities for use in endovascular training, preprocedure practice, and device testing. Such practice and training have been shown to reduce fluoroscopy time, contrast volume, and overall procedure time, as well as allow the trainee to anticipate device-related challenges when dealing with patients.4,7FIGURE 1.: A, A 3-D-printed vascular phantom of an aneurysm in the circle of Willis. B, A 3-D-printed vascular flow model with a clot simulating a stroke. C, Overall setup for simulation consisting of a 3-D-printed vascular phantom connected to a flow machine and placed under a biplane fluoroscope.By recreating routine, basic procedures or the most complex mechanical thrombectomy approaches (Figures 2A and 2B), 3-D printing has demonstrated its potential to improve outcomes and enhance education at no cost to the patient. Mokin et al12 described an in vitro 3-D model of cerebrovascular occlusion in which different thrombectomy techniques were tested. Utilizing the model, comparisons of techniques and their efficacies in recanalization of vessels were evaluated without any risk to patients. Complications encountered from the procedures neurosurgeons perform, whether simple or complex, can be devastating. Rather than practicing on a patient after observing their first trephination, groin access, or vessel catheterization, residents or fellows could initially “do one” on a 3-D model. This experience could shift the training paradigm.FIGURE 2.: A, A 3-D-printed vascular phantom with a clot injected in one the arteries to simulate a stroke. B, An example of mechanical thrombectomy using a 3-D-printed vascular phantom; a stent retriever device is deployed across the clot in the 3-D-printed flow model.Collaborative arrangements between industry and physician scientists have catalyzed the use of 3-D models in the healthcare arena. Companies such as Vascular Simulations, consisting of a multidisciplinary team of physicians, researchers, biomedical and mechanical engineers, and entrepreneurs,13 have revolutionized the manner in which neurointerventionists approach complex intracranial pathologies. Albeit still evolving and improving as the technology advances, 3-D models afford physicians the ability to simulate a case before ever touching the patient. Akin to the aviation industry, in which pilots are required to log so many hours on flight simulators, the modern surgeon may benefit from similar prerequisites. Unlike our predecessors, the modern surgeon will be able to practice on realistic and comparable models, rather than learn with the risk of harming an actual patient. Deployment of flow diverters in a difficult aneurysm and removal of a lesion in eloquent cortex are procedures that require precision and exquisite care. Three-D models can give surgeons insight into those nuances that may only have been discovered previously on a patient. This allows proceduralists to navigate tortuous anatomy via a simulator and potentially rehearse the approach, thus averting possible complications in vivo. Even the most experienced surgeons sometimes encounter patients with unique anatomic challenges. It is these cases, which may be fraught with unknown challenges, that are worth diligent reconnaissance before the actual procedure. With 3-D anatomic printing of the lesion and the patient-specific anatomy, experienced surgeons can uncover hidden pitfalls; so they are best prepared to achieve optimal patient outcomes at the time of the procedure. The next generation of physicians, specifically those in procedure-based fields, with the help of companies like Stratasys (Eden Prairie, Minnesota) that develop and manufacture 3-D printing equipment can dramatically improve their skills without ever having to place the patient in harm's way. With “see one, simulate one, learn one, and do one with ample preparation,” modern day interventionists can be better prepared to meet this paradigm shift and ultimately improve patient care and outcomes. Disclosures Dr Levy is a shareholder and has ownership interests in Intratech Medical Ltd, Blockade Medical LLC, and NeXtGen Biologics. He is a principal investigator for Covidien US SWIFT PRIME Trials, receives an honorarium from Covidien, is a consultant for Pulsar, Blockade Medical, and is on the advisory board for Stryker, NeXtGen Biologics, and MEDX. He also receives financial support from Abbott for carotid training sessions. The other authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this editorial.