2.1
Role and importance of education in microsurgery
Microsurgery was first introduced in the otolaryngology field at the beginning of the 900s. In 1921, a monocular microscope with a high magnification was first used in ear surgery for the need of a surgical field magnification for the visualization of restricted areas. This introduction required proper training of surgeons to work in a different way, with a higher magnification and with a restricted view, as well as the development of specialized instruments that could allow proper tissue handling in a finer and more precise way. Microsurgical procedures are now widespread in many specialties, and surgical training has gained importance in this context.
The American College of Surgeons–Accredited Education Institutes promote surgical simulation in the education and training of residents, and indeed, it represents an important requirement for accreditation of surgical residency programs in the United States. Microvascular surgery is one of the most demanding operative technical skills in surgery, and the microsurgical training differs from other fields due to several factors. Different basic microsurgical skills, such as operating a microscope or using microsurgery instruments, are needed to adequately perform the various procedures. The refined movements and precision required in microsurgery make it technically challenging, and it is indeed associated with a very steep learning curve. Formal course in microsurgery is usually conducted before operating on patients. Simulation-based training is usually performed in a laboratory setting with microscopes and live animal subjects. Moreover, several nonliving models have been developed to expedite the microsurgical learning curve in a less expensive and more ethical setting.
Exoscopic technology was introduced in the clinical practice to substitute the operating microscope, and various surgical procedures have been performed with optimistic clinical outcomes. The possibility to improve the surgeons’ skills in operating with the exoscope will have a great impact from this perspective. The advent of exoscope-based microsurgical training with surely expedite the widespread of this new technology, that may replace the operating microscope in many ENT centers in the near future.
2.2
Microsurgery training with exoscopic technology
The exoscope is a reliable tool for first-time users in the microsurgery training setting. As already mentioned, a simulation-based training is usually performed in a laboratory setting to improve the abilities in performing microsurgical tasks. During the last decades, the operating microscope was used to perform different kinds of microsurgical procedures in the preclinical setting. Given the widespread of the exoscopic technology in the clinical context, we expect that more and more courses will be organized to improve the ability of naïve surgeons before the clinical application.
Exoscope-based microsurgical training will gain importance for two main reasons. First, the exoscope represents a new technology, and a specific knowledge is needed to adequately use it. The operating room (OR) set-up is planned on the basis of the surgical procedure, and the surgeon should exactly know how to place the instruments (e.g., the holding system, the screen) to benefit from the exoscope ergonomics. Moreover, the surgeon should be able to manage any technological issues that could be encountered in the clinical setting. For example, the IMAGE1 PILOT should be connected to the IMAGE 1S platform when it is placed on a perfect horizontal plane. Otherwise, the image would not be fixed on the screen during the procedure, forcing the surgeon to repeatedly set the camera with longer procedure time and fragmented surgical steps. Second, the microsurgical procedures that could be performed with the exoscope are essentially unaffected by the surgical visualization and magnification tool used in terms of surgical steps. However, the surgeon should become accustomed to the new surgical visualization and magnification tool. In fact, the gaze is directed to the screen and not to the binocular microscope, and a different posture should be maintained during the surgery.
We performed a preclinical study in a simulation laboratory setting using the video telescope operating monitor (VITOM) 3D exoscope ( Fig. 2.1 ). The study was divided into two phases. The first phase was designed to assess the feasibility of an exoscope-based microsurgical simulation. The second phase was designed to compare the exoscope and the operating microscope.
Basic microsurgical exercises were proposed to first-time users. In particular, a battery of four exercises related to different surgical procedures was tested to evaluate the feasibility and the quality of the surgical training with both systems. Objective and subjective parameters were analyzed for comparison. Advantages and disadvantages were also assessed through a self-reported subjective analysis.
2.2.1
Feasibility of exoscope-based training
Naïve medical students with no prior experience in microsurgery were chosen. Before perform the exercises, all students attended a lesson specifically prepared to show how the tasks should be performed. Moreover, the VITOM 3D exoscope and the operating microscope (Zeiss OPMI CS NC31) general properties and the manipulation instructions were provided before starting the simulation. All students performed the following battery of four exercises able to assess basic microsurgical skills ( Fig. 2.2 ):
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Maneuvering test ( Fig. 2.2A ): four different coins were placed on a blue hard surface to form a rhombus with the minor and major diagonals of 20 and 40 cm, respectively. The four coins were also placed at different heights to make the test more challenging. The student was instructed to move the exoscope or the microscope to focus all the coins in a specific sequence. A good vision of all coins should be obtained changing only the focal distance to conclude the task.
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Gauze test ( Fig. 2.2B ): a single sheet of gauze of known size was fixed on a flat surface, and the student was instructed to remove a single thread of the gauze. According to the gauze web-like structure, the students had to unthread a single “box” at once using microsurgery forceps. The length of the thread removed was measured after a fixed time of 2 min.
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Pterional model test ( Fig. 2.2C ): Three different metal bars were placed inside the cerebral tissue of a pterional craniotomy model ( UpSim by UpSurgeOn). In particular, the bars were placed at different depths related to the neurovascular structures to require a refocusing during the exercise. The students were instructed to put a metal circular ring over each bar using microsurgery forceps in a specific sequence.
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Microlaryngeal test ( Fig. 2.2D ): A medium size-operating laryngoscope (Kleinsasser, Karl Storz, Tuttlingen, Germany) was used to visualize the vocal cords of a human-size silicon mannequin placed in the Boyce position. A small size needle (13 mm, 30G) was fixed at the level of anterior commissure. The student was instructed to focus on the glottis plane, and to insert, leave, and take it back a small (3 mm diameter) piece of cottonoid on the needle. The exercise was performed using microlaryngeal grasping forceps.
