Marcos Lyra

Building a real endoscopic sinus and skull-base surgery simulator.

Endoscopic sinus and skull base surgery (ESSS) is considered the “gold standard” for the treatment of many lesions of the nose, paranasal sinus, and adjacent structures. The manipulation of instruments during these procedures is challenging because of the complex anatomy and proximity to important structures such as the brain, orbital content, carotid arteries, and optic nerve, among others. Long periods of training are traditionally necessary in order to perform safe and adequate ESSS. Resident training includes anatomic lectures, a video session, cadaver dissection, direct observation of surgeries, and the realization of ESSS supervised by experienced doctors. Unfortunately, in some training hospitals, this process has been impaired by the restricted number of procedures and more difficult dissection pieces. In order to fulfill this problem, virtual simulators have been developed. These simulators use virtual-reality concepts and direct interaction mechanisms with users, such as simulation of force and feedback of touch sensation on specific structures. Unfortunately, these virtual models have some disadvantages, such as the high cost of the equipment, the use of computer-generated virtual images, some with low resolution, and touch-sensitive alterations in some structures. In addition, they do not allow the use of real instruments used on ESSS. There is a general consensus that the size and complexity of the structures in the nose and paranasal sinus are a major problem in the development and construction of a realsimulation model for ESSS. We show the development of a real model for training ESSS that allows the use of the same endoscopes and instruments used on real nasal procedures, discussing its steps, materials, and technical difficulties.

Neuroendoscopic Training: Presentation of a New Real Simulator

INTRODUCTION There are several models in use in surgical training such as cadaveric, synthetic and animal models as well as virtual reality simulators. Despite having different models for training, unfortunately, financial, technical and operational obstacles more often limit their application in developing countries. The authors have worked out a new synthetic model that could provide a reliable neuroendoscopic training method. The main goal of this study is to introduce the model and discuss relevant data regarding its use. DESCRIPTION OF THE MODEL The model is made from a synthetic thermo-retractile and thermo-sensible rubber called Neoderma. It can be used for neuroendoscopic, rhinological and endonasal skull base surgical training. Recorded videos showed a great similarity between the model and the human brain. Thirty-seven neurosurgeons were presented to the model. All of them considered it extremely useful. This model does not need any special techniques for maintenance or conservation. After training, it can be easily cleaned and stored. Furthermore, it is atoxic and easy to use. DISCUSSION A well-designed and realistic training model can help neurosurgeons to improve gradually their skills with no risks. Use of all instruments is strongly recommended. They also hope that, in the future, the model will become a standard simulator able to assist in the training of neurosurgeons.

Quality assessment of a new surgical simulator for neuroendoscopic training

OBJECT Ideal surgical training models should be entirely reliable, atoxic, easy to handle, and, if possible, low cost. All available models have their advantages and disadvantages. The choice of one or another will depend on the type of surgery to be performed. The authors created an anatomical model called the S.I.M.O.N.T. (Sinus Model Oto-Rhino Neuro Trainer) Neurosurgical Endotrainer, which can provide reliable neuroendoscopic training. The aim in the present study was to assess both the quality of the model and the development of surgical skills by trainees. METHODS The S.I.M.O.N.T. is built of a synthetic thermoretractable, thermosensible rubber called Neoderma, which, combined with different polymers, produces more than 30 different formulas. Quality assessment of the model was based on qualitative and quantitative data obtained from training sessions with 9 experienced and 13 inexperienced neurosurgeons. The techniques used for evaluation were face validation, retest and interrater reliability, and construct validation. RESULTS The experts considered the S.I.M.O.N.T. capable of reproducing surgical situations as if they were real and presenting great similarity with the human brain. Surgical results of serial training showed that the model could be considered precise. Finally, development and improvement in surgical skills by the trainees were observed and considered relevant to further training. It was also observed that the probability of any single error was dramatically decreased after each training session, with a mean reduction of 41.65% (range 38.7%-45.6%). CONCLUSIONS Neuroendoscopic training has some specific requirements. A unique set of instruments is required, as is a model that can resemble real-life situations. The S.I.M.O.N.T. is a new alternative model specially designed for this purpose. Validation techniques followed by precision assessments attested to the models feasibility.

Frameless Image-Guided Neuroendoscopy Training in Real Simulators

BACKGROUND Over the last decade, neuroendoscopy has re-emerged as an interesting option in the management of intraventricular lesions in both children and adults. Nonetheless, as it has become more difficult to use cadaveric specimens in training, the development of alternative methods was vital. The aim of this study was to analyze the performance of a real simulator, in association with image-guided navigation, as a teaching tool for the training of intraventricular endoscopic procedures. METHODS 3 real simulators were built using a special type of resin. 1 was designed to represent the abnormally enlarged ventricles, making it possible for a third ventriculostomy to be performed. The remaining 2 were designed to simulate a persons skull and brain bearing intraventricular lesions, which were placed as follows: in the foramen of Monro region, in the frontal and occipital horns of the lateral ventricles and within the third ventricle. In all models, MRI images were obtained for navigation guidance. Within the ventricles, the relevant anatomic structures and the lesions were identified through the endoscope and compared with the position given by the navigation device. The next step consisted of manipulating the lesions, using standard endoscopic techniques. RESULTS We observed that the models were MRI compatible, easy and safe to handle. They nicely reproduced the intraventricular anatomy and brain consistence, as well as simulated intraventricular lesions. The image-based navigation was efficient in guiding the surgeon through the endoscopic procedure, allowing the selection of the best approach as well as defining the relevant surgical landmarks for each ventricular compartment. Nonetheless, as expected, navigation inaccuracies occurred. After the training sessions the surgeons felt they had gained valued experience by dealing with intraventricular lesions employing endoscopic techniques. CONCLUSION The use of real simulators in association with image-guided navigation proved to be an effective tool in training for neuroendoscopy.

Anatomical pediatric model for craniosynostosis surgical training

IntroductionSeveral surgical training simulators have been created to improve the learning curve of residents in neurosurgery and plastic surgery. Laboratory training is fundamental for acquiring familiarity with the techniques of surgery and the skill in handling instruments. The aim of this study is to present a novel simulator for training in the technique of craniosynostectomy, specifically for the scaphocephaly type.Description of the simulatorThis realistic simulator was built with a synthetic thermo-retractile and thermo-sensible rubber which, when combined with different polymers, produces more than 30 different formulas. These formulas present textures, consistencies, and mechanical resistance similar to many human tissues. Fiberglass molds in the shape of the skull constitute the basic structure of the craniosynostectomy training module. It has been possible to perform computerized tomography images due to the radiopacity of this simulator and to compare the pre- and postoperative images.ResultsThe authors present a training model to practice the biparietal remodeling used in scaphocephaly correction. All aspects of the procedure are simulated: the skin incision, the subcutaneous and subperiosteal dissection, the osteotomies, and finally, the skull remodeling with absorbable microplates. The presence of superior sagittal sinus can simulate emergency situations with bleeding.ConclusionThe authors conclude that this training model can represent a fairly useful method to accustom trainees to the required surgical techniques and simulates well the steps of standard surgery for scaphocephaly. This training provides an alternative to the use of human cadavers and animal models. Furthermore, it can represent the anatomical alteration precisely as well as intraoperative emergency situations.

New anatomical simulator for pediatric neuroendoscopic practice

IntroductionThe practice of neuroendoscopic procedures requires many years of training to obtain the adequate skills to perform these operations safely. In this study, we present a new pediatric neuroendoscopic simulator that facilitates training.Description of the simulatorThis realistic simulator was built with a synthetic thermo-retractile and thermo-sensible rubber called Neoderma® which, when combined with different polymers, produces more than 30 different formulae, which present textures, consistencies, and mechanical resistances similar to many human tissues. Silicon and fiberglass molds, in the shape of the cerebral ventricles, constitute the basic structure of the neuroendoscopic training module. The module offers the possibility for practicing many basic neuroendoscopic techniques such as: navigating the ventricular system to visualize important anatomic landmarks (e.g., septal and thalamostriate veins, foramen of Monro, temporal horns, aqueduct, and fourth ventricle), performing third ventriculostomy and choroid plexus cauterization, and resecting intraventricular “tumors” that bleed.ConclusionIt is important to emphasize that it is possible to perform with this simulator not only the rigid but also the flexible endoscopy, with good correspondence to reality and no risks. Notable future perspectives can be considered regarding this new pediatric simulator, for example, to improve the learning curve for nonexperienced neurosurgeons and to spread the flexible endoscopy technique.

Surgeons’ perceptions of transanal endoscopic microsurgery using minilaparoscopic instruments in a simulator: the thinner the better

BackgroundSeveral issues have limited the widespread adoption of transanal endoscopic microsurgery (TEM). The need for specialized equipment and the steep learning curve represent one of them. To operate on within a 4-cm diameter, rectoscope represents a major technical challenge. However, minilaparoscopic surgery has been introduced to reduce invasiveness and abdominal wall trauma. In TEM, instrument miniaturization may lead to technique optimization. We hypothesized that visualization and maneuverability during TEM performed with 3-mm minilaparoscopic instruments would be superior to TEM performed with conventional 5-mm instruments.MethodsEighteen general and colorectal surgeons with experience with TEM under ten cases were recruited. Two tasks should be accomplished using the TEO®-Neoderma simulator. First, using conventional 5-mm TEO® curved-tip instruments, a “polypoid lesion” should be excised. Next, closure of the “rectal” defect should be undertaken. In the second part, the same participants repeated the same excision/closure tasks using 3-mm minilaparoscopic instruments. After tasks conclusion, participants fulfilled an evaluation questionnaire with seven questions regarding visualization and maneuverability when using 3-mm compared to 5-mm instruments.ResultsFor each one of the seven questions in the questionnaire, the score results were significantly higher for the 3-mm instruments indicating that performance with the 3-mm minilaparoscopic instruments in the TEO simulator was in all cases between “better than expected” and “much better than expected.” Appropriateness of the diameter of the minilaparoscopic instruments was the best evaluated parameter. The question addressing the ease of performing the tasks in the simulator presented the lowest mean score.ConclusionsThe perceptions of participating surgeons indicated that there is better visualization and maneuverability during basic transanal endoscopic microsurgery tasks conducted in a simulator using 3-mm minilaparoscopic instruments when compared to conventional 5-mm instruments.

Sialendoscopy Training: Presentation of a Realistic Model

Introduction Several surgical training simulators have been created for residents and young surgeons to gain experience with surgical procedures. Laboratory training is fundamental for acquiring familiarity with the techniques of surgery and skill in handing instruments. Objective The aim of this study is to present a novel simulator for training sialendoscopy. Method This realistic simulator was built with a synthetic thermo-retractile, thermo-sensible rubber which, when combined with different polymers, produces more than 30 different formulas. These formulas present textures, consistencies, and mechanical resistance are similar to many human tissues. Results The authors present a training model to practice sialendoscopy. All aspects of the procedure are simulated: month opening, dilatation of papillae, insert of the scope, visualization of stones, extraction of these stones with grasping or baskets, and finally, stone fragmentation with holmium laser. Conclusion This anatomical model for sialendoscopy training should be considerably useful to abbreviate the learning curve during the qualification of young surgeons while minimizing the consequences of technical errors.

Board 131 - Program Innovations Abstract The Combination of Virtual and Realistic Anatomical Models in Spine Surgical Training (Submission #1032)

Introduction/Background The Neurosurgical and Orthopaedic education are a long, laborious process, requiring many years of supervised, directed, hands-on training and the traditional surgical education has consisted of a mixture of didactic lessons with periodic clinical and surgical apprenticeship based experience. In recent years, shifting paradigms in training have dramatically changed this traditional apprenticeship model of medical education. In order to increase patient safety and improve treatment outcomes, several strategies such as problem based learning and objective structured clinical examination have promoted the development of new curriculums in surgical education. 1,2,,3,4,5 The surgical simulation, in this context, can help address shortcomings in the traditional apprenticeship training model by providing residents with opportunities to practice important procedures that they may not otherwise encounter and practice procedures efficiently until competency is achieved and mainly without exposing live patients to undue risk.6 From these principles, the main purpose of this study is to present the virtual associated with realistic simulation in spine surgery. For the virtual simulation we created 3D videos that reproduce some spinal surgical approaches; for physical simulation we created a lumbar spine model, as similar as possible to the patient’s anatomy. Methods The 3D videos were developed by a graphic designer in partnership with Neurosurgeons and Orthopaedists team.The computerized program used was 3DS Max. They were based on reproduction of tridimensional anatomy of the lumbar spine and also some pathologies and their surgical approaches.The modules available were: pedicle screw placement, lumbar microdiscetomy and spinal stenosis surgery. This virtual model doesn’t allow the interaction with the trainee, however its goal was to stimulate the ability to mentally manipulate objects in three dimensions, recreating the intraoperative scenario, essential to the practice of these surgeries. The real simulator was built with a synthetic thermo-retractile and thermo-sensible rubber which, when combined with different polymers, produces more than 30 different formulas. These formulas present textures, consistencies and mechanical resistance similar to many human tissues. It was possible to perform computerized tomography images due to the radiopacity of this simulator and to compare the pre and post operative images. The authors present a training model to practice the mental tridimensional reconstruction of each surgical approach through videos visualization and with the realistic model was possible to practice the pedicle screw placement, the lumbar stenosis correction and the lumbar microdiscectomy. There were many possibilities to training: the skin incision; the subcutaneous and subperiostal dissection; the muscular, open laminectomy and discectomy and pedicles screws placement. The presence of the spinal cord and dura mater filled with saline solution representing the cerebrospinal fluid (CSF),can simulate some interesting situations as CSF leak, with the possibility to solve the problem. Fifteen experienced surgeons (spine experts) evaluated these models and responded to the questionnaire if the simulation can have a beneficial education tool. The proportion of the answers to a question were estimated by the confidence intervals. Results: Conclusion The experts concluded that this virtual simulation provides a highly effective way to work with 3D data and it significantly enhances teaching of surgical anatomy and operative strategies in the neurosurgical and orthopaedic fields. Furthermore, the spine realistic simulator promotes a safer environment for the development of surgical skills and constitutes a valid, reliable and feasible tool for surgical training. The combination of these virtual and realistic tools have the potential to improve /abbreviate the non-experienced learning curve. References 1. Dunnington G, Reisner L, Witzke D, Fulginiti J: Structured single-observer Methods of evaluation for the assessment of ward performance on the surgical clerkship. Am J Surg 159:423-426, 1990. 2. Ferenchick G, Simpson D, Blackman J, DaRosa D, Dunnington G: Strategies for efficient and effective teaching in the ambulatory care setting. Acad Med 72:277-280, 1997. 3. McGregor DB, Arcomano TR, Bjerke HS, Little AG: Problem orientation is a new approach to surgical education. Am J Surg 170:656-658, 1995. 4. Sloan DA, Donnelly MB, Johnson SB, Schwartz RW, Strodel WE: Use of an Objective Structured Clinical Examination (OSCE) to measure improvement in clinical competence during the surgical internship. Surgery 114:343-350, 1993. 5. Sloan DA, Donnelly MB, Schwartz RW, Strodel WE: The Objective Structured Clinical Examination. The new gold standard for evaluating postgraduate clinical performance. Ann Surg 222:735-742, 1995. 6. Karam, Kho JY, Yehyawi TM, Ohrt GT, Thomas GW, Jonard B, Anderson DD, Marsh JL. Application of surgical skill simulation training and assessment in orthopaedic trauma. Iowa Orthop J. 2012;32:76-82. Disclosures None.

Board 536 - Technology Innovations Abstract Anatomical Shoulder Simulator for Arthroscopy Training (Submission #831)

Introduction/Background Several simulators have been created in an attempt to improve the learning curve of residents in arthroscopy surgery. Laboratory training is fundamental for acquiring familiarity with surgical techniques and skill in handling instruments. The aim of this study is to present a new simulator for shoulder arthroscopic surgery, specifically for the articular and sub-acromial procedures. Methods This real simulator was built with a synthetic thermo-retractile and thermo-sensible rubber which, when combined with different polymers, produces more than 30 different formulas. These formulas present textures, consistencies and mechanical resistance similar to many human tissues. It is possible to use an arthroscopy pump to allow distension and visualization to be maintained during procedures. Fiberglass molds, in the shape of the humerus and scapula, have made it possible to use shaver devices and implant different materials. It`s now possible to obtain computerized tomography images due to the radiopacity of this simulator and to compare the pre and postoperative images. The authors present a training model to practice shoulder arthroscopy surgery. There are many possibilities for training, identification of anatomic landmarks; triangulation skills and for performing biceps tenotomy or tenodesis, SLAP repair, Bankart surgery for instability, rotator cuff repair, sub-acromial decompression and stabilization of acromioclavicular joint dislocation. Results: Conclusion The authors conclude that this training model represents a fairly useful method to accustom trainees to the required surgical techniques and usefully simulates the steps of standard arthroscopy surgery. This training provides an alternative to the use of human cadavers and animal models. Furthermore, it can accurately demonstrate the anatomical alterations as well as the shoulder conditions requiring surgery. Disclosures None.