Man, Mind, and Machine: The Past and Future of Virtual Reality Simulation in Neurologic Surgery

Simulation of soft tissue deformation under physiological motion based on complementary dynamic method

BACKGROUND AND OBJECTIVE

Physiological motions have a significant impact on soft tissue deformation and accuracy of surgical procedures, which is essential for realistic surgical simulation. While existing studies offer accurate simulation of soft tissue deformation, integrating physiological motions into deformation models of soft tissue remains a challenging task.

METHODS

This paper introduces a novel deformation model, based on complementary dynamics, to animate soft tissue deformation under physiological motion. The finite element method is incorporated to accurately characterize the elastic behavior of the soft tissue. Mathematical models of physiological motion are utilized and the physiological effects are converted into displacements of a predefined set of handles within the soft tissue mesh. Complementary displacements derived from the inherent dynamics of the soft tissue are calculated, enabling the simulation of physiological motions and elastic behaviors in soft tissue deformation.

RESULTS

Experiments were conducted to evaluate the performance and effectiveness of the proposed method in simulating soft tissue deformation under physiological motion. The simulation results show that the soft tissues exhibit physiological motion that corresponds to the rhythm of arterial pressure fluctuations, heartbeat or respiratory. Furthermore, the presented method exhibits stable performance compared with existing force-based methods.

CONCLUSIONS

Both elastic behaviors and physiological motions of soft tissue deformation can be governed by the proposed method. A high degree of realistic visualization is achieved for virtual surgery simulation.

State of the Art in Immersive Interactive Technologies for Surgery Simulation: A Review and Prospective

Immersive technologies have thrived on a strong foundation of software and hardware, injecting vitality into medical training. This surge has witnessed numerous endeavors incorporating immersive technologies into surgery simulation for surgical skills training, with a growing number of researchers delving into this domain. Relevant experiences and patterns need to be summarized urgently to enable researchers to establish a comprehensive understanding of this field, thus promoting its continuous growth. This study provides a forward-looking perspective by reviewing the latest development of immersive interactive technologies for surgery simulation. The investigation commences from a technological standpoint, delving into the core aspects of virtual reality (VR), augmented reality (AR) and mixed reality (MR) technologies, namely, haptic rendering and tracking. Subsequently, we summarize recent work based on the categorization of minimally invasive surgery (MIS) and open surgery simulations. Finally, the study showcases the impressive performance and expansive potential of immersive technologies in surgical simulation while also discussing the current limitations. We find that the design of interaction and the choice of immersive technology in virtual surgery development should be closely related to the corresponding interactive operations in the real surgical speciality. This alignment facilitates targeted technological adaptations in the direction of greater applicability and fidelity of simulation.

Use of 3-Dimensional Modeling and Augmented/Virtual Reality Applications in Microsurgical Neuroanatomy Training

BACKGROUND

Understanding the microsurgical neuroanatomy of the brain is challenging yet crucial for safe and effective surgery. Training on human cadavers provides an opportunity to practice approaches and learn about the brain's complex organization from a surgical view. Innovations in visual technology, such as virtual reality (VR) and augmented reality (AR), have immensely added a new dimension to neuroanatomy education. In this regard, a 3-dimensional (3D) model and AR/VR application may facilitate the understanding of the microsurgical neuroanatomy of the brain and improve spatial recognition during neurosurgical procedures by generating a better comprehension of interrelated neuroanatomic structures.

OBJECTIVE

To investigate the results of 3D volumetric modeling and AR/VR applications in showing the brain's complex organization during fiber dissection.

METHODS

Fiber dissection was applied to the specimen, and the 3D model was created with a new photogrammetry method. After photogrammetry, the 3D model was edited using 3D editing programs and viewed in AR. The 3D model was also viewed in VR using a head-mounted display device.

RESULTS

The 3D model was viewed in internet-based sites and AR/VR platforms with high resolution. The fibers could be panned, rotated, and moved freely on different planes and viewed from different angles on AR and VR platforms.

CONCLUSION

This study demonstrated that fiber dissections can be transformed and viewed digitally on AR/VR platforms. These models can be considered a powerful teaching tool for improving the surgical spatial recognition of interrelated neuroanatomic structures. Neurosurgeons worldwide can easily avail of these models on digital platforms.

Scoping review: The use of augmented reality in clinical anatomical education and its assessment tools

The purpose of this review was to identify the different augmented reality (AR) modalities used to teach anatomy to students, health professional trainees, and surgeons, and to examine the assessment tools used to evaluate the performance of various AR modalities. A scoping review of four databases was performed using variations of: (1) AR, (2) medical or anatomical teaching/education/training, and (3) anatomy or radiology or cadaver. Scientific articles were identified and screened for the inclusion and exclusion criteria as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses with extension for scoping reviews guidelines. Virtual reality was an exclusion criterion. From this scoping review, data were extracted from a total of 54 articles and the following four AR modalities were identified: head-mounted display, projection, instrument and screen, and mobile device. The usability, feasibility, and acceptability of these AR modalities were evaluated using a variety of quantitative and qualitative assessment tools. Within more recent years of AR integration into anatomy education, the assessment of visuospatial ability, cognitive load, time on task, and increasing academic achievement outcomes are variables of interest, which continue to warrant more exploration. Sufficiently powered studies using validated assessment tools must be conducted to better understand the role of AR in anatomical education.

Evaluation of simulation models in neurosurgical training according to face, content, and construct validity: a systematic review

BACKGROUND

Neurosurgical training has been traditionally based on an apprenticeship model. However, restrictions on clinical exposure reduce trainees' operative experience. Simulation models may allow for a more efficient, feasible, and time-effective acquisition of skills. Our objectives were to use face, content, and construct validity to review the use of simulation models in neurosurgical education.

METHODS

PubMed, Web of Science, and Scopus were queried for eligible studies. After excluding duplicates, 1204 studies were screened. Eighteen studies were included in the final review.

RESULTS

Neurosurgical skills assessed included aneurysm clipping (n = 6), craniotomy and burr hole drilling (n = 2), tumour resection (n = 4), and vessel suturing (n = 3). All studies assessed face validity, 11 assessed content, and 6 assessed construct validity. Animal models (n = 5), synthetic models (n = 7), and VR models (n = 6) were assessed. In face validation, all studies rated visual realism favourably, but haptic realism was key limitation. The synthetic models ranked a high median tactile realism (4 out of 5) compared to other models. Assessment of content validity showed positive findings for anatomical and procedural education, but the models provided more benefit to the novice than the experienced group. The cadaver models were perceived to be the most anatomically realistic by study participants. Construct validity showed a statistically significant proficiency increase among the junior group compared to the senior group across all modalities.

CONCLUSION

Our review highlights evidence on the feasibility of implementing simulation models in neurosurgical training. Studies should include predictive validity to assess future skill on an individual on whom the same procedure will be administered. This study shows that future neurosurgical training systems call for surgical simulation and objectively validated models.

Virtual reality-based 3-dimensional localization of stereotactic EEG (SEEG) depth electrodes and related brain anatomy in pediatric epilepsy surgery

INTRODUCTION

The increasing use of stereoelectroencephalography (SEEG) in the USA and the need for three-dimensional (3D) appreciation of complex spatial relationships between implanted stereotactic EEG depth electrodes and surrounding brain and cerebral vasculature are a challenge to clinicians who are used to two-dimensional (2D) appreciation of cortical anatomy having been traditionally trained on 2D radiologic imaging. Virtual reality and its 3D renderings have grown increasingly common in the multifaceted practice of neurosurgery. However, there exists a paucity in the literature regarding this emerging technology in its utilization of epilepsy surgery.

METHODS

An IRB-approved, single-center retrospective study identifying all SEEG pediatric patients in which virtual reality was applied was observed.

RESULTS

Of the 46 patients identified who underwent an SEEG procedure, 43.5% (20/46) had a 3D rendering (3DR) of their SEEG depth electrodes. All 3DRs were used during patient-family education and discussion among the Epilepsy multidisciplinary team meetings, while 35% (7/20) were used during neuronavigation in surgery. Three successful representative cases of its application were presented.

DISCUSSION

Our institution's experience regarding virtual reality in the 3D representation of SEEG depth electrodes and the application to pre-surgical planning, patient-family education, multidisciplinary communication, and intraoperative neuronavigation demonstrate its applicability in comprehensive epilepsy patient care.

Virtual Reality in the Neurosciences: Current Practice and Future Directions

Virtual reality has made numerous advancements in recent years and is used with increasing frequency for education, diversion, and distraction. Beginning several years ago as a device that produced an image with only a few pixels, virtual reality is now able to generate detailed, three-dimensional, and interactive images. Furthermore, these images can be used to provide quantitative data when acting as a simulator or a rehabilitation device. In this article, we aim to draw attention to these areas, as well as highlight the current settings in which virtual reality (VR) is being actively studied and implemented within the field of neurosurgery and the neurosciences. Additionally, we discuss the current limitations of the applications of virtual reality within various settings. This article includes areas in which virtual reality has been used in applications both inside and outside of the operating room, such as pain control, patient education and counseling, and rehabilitation. Virtual reality's utility in neurosurgery and the neurosciences is widely growing, and its use is quickly becoming an integral part of patient care, surgical training, operative planning, navigation, and rehabilitation.

VolumetricOR: A New Approach to Simulate Surgical Interventions in Virtual Reality for Training and Education

BACKGROUND

Surgical training is primarily carried out through observation during assistance or on-site classes, by watching videos as well as by different formats of simulation. The simulation of physical presence in the operating theatre in virtual reality might complement these necessary experiences. A prerequisite is a new education concept for virtual classes that communicates the unique workflows and decision-making paths of surgical health professions (i.e. surgeons, anesthesiologists and surgical assistants) in an authentic and immersive way. For this project, media scientists, designers and surgeons worked together to develop the foundations for new ways of conveying knowledge using virtual reality in surgery.

MATERIALS AND METHOD

A technical workflow to record and present volumetric videos of surgical interventions in a photorealistic virtual operating room was developed. Situated in the virtual reality demonstrator called VolumetricOR, users can experience and navigate through surgical workflows as if they are physically present. The concept is compared with traditional video-based formats of digital simulation in surgical training.

RESULTS

VolumetricOR let trainees experience surgical action and workflows (a) three-dimensionally, (b) from any perspective and (c) in real scale. This improves the linking of theoretical expertise and practical application of knowledge and shifts the learning experience from observation to participation.

DISCUSSION

Volumetric training environments allow trainees to acquire procedural knowledge before going to the operating room and could improve the efficiency and quality of the learning and training process for professional staff by communicating techniques and workflows when the possibilities of training on-site are limited.

Virtual Reality in Neurosurgery: Beyond Neurosurgical Planning

Background: While several publications have focused on the intuitive role of augmented reality (AR) and virtual reality (VR) in neurosurgical planning, the aim of this review was to explore other avenues, where these technologies have significant utility and applicability. Methods: This review was conducted by searching PubMed, PubMed Central, Google Scholar, the Scopus database, the Web of Science Core Collection database, and the SciELO citation index, from 1989–2021. An example of a search strategy used in PubMed Central is: “Virtual reality” [All Fields] AND (“neurosurgical procedures” [MeSH Terms] OR (“neurosurgical” [All Fields] AND “procedures” [All Fields]) OR “neurosurgical procedures” [All Fields] OR “neurosurgery” [All Fields] OR “neurosurgery” [MeSH Terms]). Using this search strategy, we identified 487 (PubMed), 1097 (PubMed Central), and 275 citations (Web of Science Core Collection database). Results: Articles were found and reviewed showing numerous applications of VR/AR in neurosurgery. These applications included their utility as a supplement and augment for neuronavigation in the fields of diagnosis for complex vascular interventions, spine deformity correction, resident training, procedural practice, pain management, and rehabilitation of neurosurgical patients. These technologies have also shown promise in other area of neurosurgery, such as consent taking, training of ancillary personnel, and improving patient comfort during procedures, as well as a tool for training neurosurgeons in other advancements in the field, such as robotic neurosurgery. Conclusions: We present the first review of the immense possibilities of VR in neurosurgery, beyond merely planning for surgical procedures. The importance of VR and AR, especially in “social distancing” in neurosurgery training, for economically disadvantaged sections, for prevention of medicolegal claims and in pain management and rehabilitation, is promising and warrants further research.

Three-Dimensional Modeling of Complex Pediatric Intracranial Aneurysmal Malformations With a Virtual Reality System

INTRODUCTION

Surgical simulation is valuable in neurovascular surgery given the progressive rarity of these cases and their technical complexity, but its use has not been well described for pediatric vascular pathologies. We herein review the use of surgical simulation at our institution for complex pediatric aneurysmal malformations.

METHODS

A retrospective review of patients treated for middle cerebral artery aneurysmal malformations with surgical simulation assistance (SuRgical Planner [SRP]; Surgical Theater, Mayfield Village, OH) during a 2-year period at Rady Children's Hospital of San Diego was performed.

RESULTS

In 5 pediatric patients with complex MCA aneurysmal malformations (mean age = 33.2 ± 49.9 months), preoperative 3-dimensional (3D) interactive modeling informed treatment planning and enhanced surgeon understanding of the vascular pathology. Availability of intraoperative simulation also aided real-time anatomical understanding during surgery. Specific benefits of simulation for these cases included characterization of involved perforating vessels, as well as an enhanced understanding of flow patterns within associated complex arteriovenous fistulas and feeding vessel/daughter branch anatomy. Despite the complexity of the lesions treated, use of simulation qualitatively enhanced surgeon confidence. There were no perioperative complications for patients treated with open surgery.

CONCLUSIONS

Surgical simulation may aid in the treatment of complex pediatric aneurysmal malformations.

Validation of High Precision Robot-Assisted Methods for Intracranial Applications: Preliminary Study

BACKGROUND

This work attempts to simulate a robot-based autonomous targeted neurosurgical procedure such as biopsy on a vegetable specimen. The objective of the work is to validate the robot-based autonomous neuroregistration and neuronavigation for neurosurgery in terms of stereotactic navigation and target accuracy.

CASE DESCRIPTION

A vegetable (carrot) fixed in a tray was used as a model. The tray was affixed with multiple markers. The robot autonomously registers the subject precisely and subsequently accesses the target. The navigation trajectory closely follows the path from the entry point to the target point, as specified in the medical image. The replication of procedures reveals that the target accuracies are within 1 mm. The results based on the case studies are presented. Intricate cases in terms of entry hole size, depth, and size of the target are considered for both phantom and vegetable trials.

CONCLUSIONS

The results of the case studies show enhanced and consistent performance characteristics in terms of accuracy, precision, and repeatability with the added advantage of the economy of time. The case studies serve as validation for a high precision robot-assisted neuroregistration and neuronavigation task for neurosurgery and pave the way for further animal and human trials.

Effectiveness of the Thoracic Pedicle Screw Placement Using the Virtual Surgical Training System: A Cadaver Study

BACKGROUND

The virtual simulation surgery has initially exhibited its promising potentials in neurosurgery training.

OBJECTIVE

To evaluate effectiveness of the Virtual Surgical Training System (VSTS) on novice residents placing thoracic pedicle screws in a cadaver study.

METHODS

A total of 10 inexperienced residents participated in this study and were randomly assigned to 2 groups. The group using VSTS to learn thoracic pedicle screw fixation was the simulation training (ST) group and the group receiving an introductory teaching session was the control group. Ten fresh adult spine specimens including 6 males and 4 females with a mean age of 58.5 yr (range: 33-72) were collected and randomly allocated to the 2 groups. After exposing anatomic structures of thoracic spine, the bilateral pedicle screw placement of T6-T12 was performed on each cadaver specimen. The postoperative computed tomography scan was performed on each spine specimen, and experienced observers independently reviewed the placement of the pedicle screws to assess the incidence of pedicle breach.

RESULTS

The screw penetration rates of the ST group (7.14%) was significantly lower in comparison to the control group (30%, P < .05). Statistically significant difference in acceptable rates of screws also occurred between the ST (100%) and control (92.86%) group (P < .05). In addition, the average screw penetration distance in control group (2.37 mm ± 0.23 mm) was significantly greater than ST group (1.23 mm ± 0.56 mm, P < .05).

CONCLUSION

The virtual reality surgical training of thoracic pedicle screw instrumentation effectively improves surgical performance of novice residents compared to those with traditional teaching method, and can help new beginners to master the surgical technique within shortest period of time.

Virtual or Augmented Reality to Enhance Surgical Education and Surgical Planning

Virtual reality and augmented reality technologies have evolved with a growing presence in both clinical care and surgical training.

Simulation Training Methods in Neurological Surgery

Simulation training plays a paramount role in medicine, especially when it comes to mastering surgical skills. By simulating, students gain not only confidence, but expertise, learning to apply theory in a safe environment. As the technological arsenal improved, virtual reality and physical simulators have developed and are now an important part of the Neurosurgery training curriculum. Based on deliberate practice in a controlled space, simulation allows psychomotor skills augment without putting neither patients nor students at risk. When compared to the master-apprentice ongoing model of teaching, simutation becomes even more appealing as it is time-efficient, shortening the learning curve and ultimately leading to error reduction, which is reflected by diminished health care costs in the long run. In this chapter we will discuss the current state of neurosurgery simulation, highlight the potential benefits of this approach, assessing specific training methods and making considerations towards the future of neurosurgical simulation.

Virtual Reality and Simulation in Neurosurgical Training

Recent biotechnological advances, including three-dimensional microscopy and endoscopy, virtual reality, surgical simulation, surgical robotics, and advanced neuroimaging, have continued to mold the surgeon-computer relationship. For developing neurosurgeons, such tools can reduce the learning curve, improve conceptual understanding of complex anatomy, and enhance visuospatial skills. We explore the current and future roles and application of virtual reality and simulation in neurosurgical training.

Utilizing virtual and augmented reality for educational and clinical enhancements in neurosurgery

Neurosurgery has undergone a technological revolution over the past several decades, from trephination to image-guided navigation. Advancements in virtual reality (VR) and augmented reality (AR) represent some of the newest modalities being integrated into neurosurgical practice and resident education. In this review, we present a historical perspective of the development of VR and AR technologies, analyze its current uses, and discuss its emerging applications in the field of neurosurgery.

Residency program trainee-satisfaction correlate with results of the European board examination in neurosurgery

INTRODUCTION

Substantial country differences in neurosurgical training throughout Europe have recently been described, ranging from subjective rating of training quality to objective working hours per week. The aim of this study was to analyse whether these differences translate into the results of the written and oral part of the European Board Examination in Neurological Surgery (EBE-NS).

METHODS

Country-specific composite scores for satisfaction with quality of theoretical and practical training, as well as working hours per week, were obtained from an electronic survey distributed among European neurosurgical residents between June 2014 and March 2015. These were related to anonymous country-specific results of the EBE-NS between 2009 and 2016, using uni- and multivariate linear regression analysis.

RESULTS

A total of n = 1025 written and n = 63 oral examination results were included. There was a significant linear relationship between the country-specific EBE-NS result in the written part and the country-specific composite score for satisfaction with quality of theoretical training [adjusted regression coefficient (RC) -3.80, 95 % confidence interval (CI) -5.43-7 -2.17, p < 0.001], but not with practical training or working time. For the oral part, there was a linear relationship between the country-specific EBE-NS result and the country-specific composite score for satisfaction with quality of practical training (RC 9.47, 95 % CI 1.47-17.47, p = 0.021), however neither with satisfaction with quality of theoretical training nor with working time.

CONCLUSION

With every one-step improvement on the country-specific satisfaction score for theoretical training, the score in the EBE-NS Part 1 increased by 3.8 %. With every one-step improvement on the country-specific satisfaction score for practical training, the score in the EBE-NS Part 2 increased by 9.47 %. Improving training conditions is likely to have a direct positive influence on the knowledge level of trainees, as measured by the EBE-NS. The effect of the actual working time on the theoretical and practical knowledge of neurosurgical trainees appears to be insignificant.

Simulator-Based Angiography and Endovascular Neurosurgery Curriculum: A Longitudinal Evaluation of Performance Following Simulator-Based Angiography Training

This study establishes performance metrics for angiography and neuroendovascular surgery procedures based on longitudinal improvement in individual trainees with differing levels of training and experience.

Over the course of 30 days, five trainees performed 10 diagnostic angiograms, coiled 10 carotid terminus aneurysms in the setting of subarachnoid hemorrhage, and performed 10 left middle cerebral artery embolectomies on a Simbionix Angio Mentor™ simulator. All procedures were nonconsecutive. Total procedure time, fluoroscopy time, contrast dose, heart rate, blood pressures, medications administered, packing densities, the number of coils used, and the number of stent-retriever passes were recorded. Image quality was rated, and the absolute value of technically unsafe events was recorded. The trainees’ device selection, macrovascular access, microvascular access, clinical management, and the overall performance of the trainee was rated during each procedure based on a traditional Likert scale score of 1=fail, 2=poor, 3=satisfactory, 4=good, and 5=excellent. These ordinal values correspond with published assessment scales on surgical technique.

After performing five diagnostic angiograms and five embolectomies, all participants demonstrated marked decreases in procedure time, fluoroscopy doses, contrast doses, and adverse technical events; marked improvements in image quality, device selection, access scores, and overall technical performance were additionally observed (p < 0.05). Similarly, trainees demonstrated marked improvement in technical performance and clinical management after five coiling procedures (p < 0.05). However, trainees with less prior experience deploying coils continued to experience intra-procedural ruptures up to the eighth embolization procedure; this observation likely corresponded with less tactile procedural experience to an exertion of greater force than appropriate for coil placement.

Trainees across all levels of training and prior experience demonstrated a significant performance improvement after completion of our simulator curriculum consisting of five diagnostic angiograms, five embolectomy cases, and 10 aneurysm coil embolizations.

Use of a surgical rehearsal platform and improvement in aneurysm clipping measures: results of a prospective, randomized trial

OBJECTIVE The field of neurosurgery is constantly undergoing improvements and advances, both in technique and technology. Cerebrovascular neurosurgery is no exception, with endovascular treatments changing the treatment paradigm. Clipping of aneurysms is still necessary, however, and advances are still being made to improve patient outcomes within the microsurgical treatment of aneurysms. Surgical rehearsal platforms are surgical simulators that offer the opportunity to rehearse a procedure prior to entering the operative suite. This study is designed to determine whether use of a surgical rehearsal platform in aneurysm surgery is helpful in decreasing aneurysm dissection time and clip manipulation of the aneurysm. METHODS The authors conducted a blinded, prospective, randomized study comparing key effort and time variables in aneurysm clip ligation surgery with and without preoperative use of the SuRgical Planner (SRP) surgical rehearsal platform. Initially, 40 patients were randomly assigned to either of two groups: one in which surgery was performed after use of the SRP (SRP group) and one in which surgery was performed without use of the SRP (control group). All operations were videotaped. After exclusion of 6 patients from the SRP group and 9 from the control group, a total of 25 surgical cases were analyzed by a reviewer blinded to group assignment. The videos were analyzed for total microsurgical time, number of clips used, and number of clip placement attempts. Means and standard deviations (SDs) were calculated and compared between groups. RESULTS The mean (± SD) amount of operative time per clip used was 920 ± 770 seconds in the SRP group and 1294 ± 678 seconds in the control group (p = 0.05). In addition, the mean values for the number of clip attempts, total operative time, ratio of clip attempts to clips used, and time per clip attempt were all lower in the SRP group, although the between-group differences were not statistically significant. CONCLUSIONS Preoperative rehearsal with SRP increased efficiency and safety in aneurysm microsurgery as demonstrated by the statistically significant improvement in time per clip used. Although the rest of the outcomes did not demonstrate statistically significant between-group differences, the fact that the SRP group showed improvement in mean values for all measures studied suggests that preoperative rehearsal may increase the efficiency and safety of aneurysm microsurgery. Future studies aimed at improving patient outcome and safety during surgical clipping of aneurysms will be needed to keep pace with the quickly advancing endovascular field.

An in vivo morphometry study on the standard transsylvian trajectory for mesial temporal lobe epilepsy surgery

A safe and appropriate surgical approach to the medial temporal structure is a prerequisite to perform surgeries for temporal lobe epilepsy. We used in vivo morphometry to identify the standard direction for entry into the inferior horn of the lateral ventricle via the Sylvian fissure: an important initial step in performing transsylvian selective amygdalohippocampectomy. 3D magnetic resonance images obtained from 28 patients without intra-parenchymal lesions were re-oriented to demonstrate all points in the Talairach space of the brain. The limen insulae and the midpoint between the hippocampal sulcus and the innominate sulcus on the coronal slice through the posterior edge of the amygdala were defined as the start and target points, respectively. We evaluated the direction of the vector between these two points and its validity in the brain of 12 patients with temporal lobe epilepsy. The direction of the mean approach vector was 52.4° posteriorly and 16.2° inferiorly. The mean approach vector on the axial plane showed the approximate parallelism with the sphenoid ridge in individual cases. The computer simulation revealed that our average approach vector correctly entered the inferior horn of the lateral ventricle in all temporal lobe epilepsy brains. In vivo morphometry may contribute to the further development of safe and minimally-invasive neurosurgical procedures.

Ureteroscopy and cystoscopy training: comparison between transparent and non-transparent simulators

BACKGROUND

Simulators have been widely used to train operational skills in urology, how to improve its effectiveness deserves further investigation. In this paper, we evaluated training using a novel transparent anatomic simulator, an opaque model or no simulator training, with regard to post-training ureteroscopy and cystoscopy proficiency.

METHODS

Anatomically correct transparent and non-transparent endourological simulators were fabricated. Ten experienced urologists provided a preliminary evaluation of the models as teaching tools. 36 first-year medical students underwent identical theoretical training and a 50-point examination of theoretical knowledge. The students were randomly assigned to receive training with the transparent simulator (Group 1), the non-transparent simulator (Group 2) or detailed verbal instruction only (Group 3). 12 days after the training session, the trainees' skills at ureteral stent insertion and removal were evaluated using the Uro-Scopic Trainer and rated on an Objective Structured Assessment of Technical Skills (OSATS) scale.

RESULTS

The new simulators were successfully fabricated in accordance with the design parameters. Of the ten urologists invited to evaluate the devices, 100% rated the devices as anatomically accurate, 90% thought both models were easy to use and 80% thought they were good ureteroscopy and cystoscopy training tools. The scores on the theoretical knowledge test were comparable among the training groups, and all students were able to perform ureteral stent insertion and removal. The mean OSATS scores of groups 1, 2 and 3 were 21.83 ± 3.64, 18.50 ± 4.03 and 15.58 ± 2.23 points, respectively, (p = 0.001).

CONCLUSIONS

Simulator training allowed students to achieve higher ureteroscopic and cystoscopic proficiency, and transparent simulators were more effective than non-transparent simulators.

Simulation and resident education in spinal neurosurgery

BACKGROUND

A host of factors have contributed to the increasing use of simulation in neurosurgical resident education. Although the number of simulation-related publications has increased exponentially over the past two decades, no studies have specifically examined the role of simulation in resident education in spinal neurosurgery.

METHODS

We performed a structured search of several databases to identify articles detailing the use of simulation in spinal neurosurgery education in an attempt to catalogue potential applications for its use.

RESULTS

A brief history of simulation in medicine is given, followed by current trends of spinal simulation utilization in residency programs. General themes from the literature are identified that are integral for implementing simulation into neurosurgical residency curriculum. Finally, various applications are reported.

CONCLUSION

The use of simulation in spinal neurosurgery education is not as ubiquitous in comparison to other neurosurgical subspecialties, but many promising methods of simulation are available for augmenting resident education.

Design and evaluation of a new synthetic brain simulator for endoscopic third ventriculostomy

OBJECT

Endoscopic third ventriculostomy (ETV) is an effective but technically demanding procedure with significant risk. Current simulators, including human cadavers, animal models, and virtual reality systems, are expensive, relatively inaccessible, and can lack realistic sensory feedback. The purpose of this study was to construct a realistic, low-cost, reusable brain simulator for ETV and evaluate its fidelity.

METHODS

A brain silicone replica mimicking normal mechanical properties of a 4-month-old child with hydrocephalus was constructed, encased in the replicated skull, and immersed in water. Realistic intraventricular landmarks included the choroid plexus, veins, mammillary bodies, infundibular recess, and basilar artery. The thinned-out third ventricle floor, which dissects appropriately, is quickly replaceable. Standard neuroendoscopic equipment including irrigation is used. Bleeding scenarios are also incorporated. A total of 16 neurosurgical trainees (Postgraduate Years 1-6) and 9 pediatric and adult neurosurgeons tested the simulator. All participants filled out questionnaires (5-point Likert-type items) to rate the simulator for face and content validity.

RESULTS

The simulator is portable, robust, and sets up in minutes. More than 95% of participants agreed or strongly agreed that the simulator's anatomical features, tissue properties, and bleeding scenarios were a realistic representation of that seen during an ETV. Participants stated that the simulator helped develop the required hand-eye coordination and camera skills, and the training exercise was valuable.

CONCLUSIONS

A low-cost, reusable, silicone-based ETV simulator realistically represents the surgical procedure to trainees and neurosurgeons. It can help them develop the technical and cognitive skills for ETV including dealing with complications.

Evaluation of a novel phantom-based neurosurgical training system

Background:

The complexity of neurosurgical interventions demands innovative training solutions and standardized evaluation methods that in recent times have been the object of increased research interest. The objective is to establish an education curriculum on a phantom-based training system incorporating theoretical and practical components for important aspects of brain tumor surgery.

Methods:

Training covers surgical planning of the optimal access path based on real patient data, setup of the navigation system including phantom registration and navigated craniotomy with real instruments. Nine residents from different education levels carried out three simulations on different data sets with varying tumor locations. Trainings were evaluated by a specialist using a uniform score system assessing tumor identification, registration accuracy, injured structures, planning and execution accuracy, tumor accessibility and required time.

Results:

Average scores improved from 16.9 to 20.4 between first and third training. Average time to craniotomy improved from 28.97 to 21.07 min, average time to suture improved from 37.83 to 27.47 min. Significant correlations were found between time to craniotomy and number of training (P < 0.05), between time to suture and number of training (P < 0.05) as well as between score and number of training (P < 0.01).

Conclusion:

The training system is evaluated to be a suitable training tool for residents to become familiar with the complex procedures of autonomous neurosurgical planning and conducting of craniotomies in tumor surgeries. Becoming more confident is supposed to result in less error-prone and faster operation procedures and thus is a benefit for both physicians and patients.

Surgical training is undermined by inadequate provision of laparoscopic surgical simulators

In parallel with the introduction of working time regulations that have led to changes in working patterns, surgical trainees are taking longer to achieve operative competencies and logging fewer surgical cases. 1–3 The existing style of surgical training appears to provide insufficient operative exposure in limited working hours.

A neurosurgical phantom-based training system with ultrasound simulation

BACKGROUND

Brain tumor surgeries are associated with a high technical and personal effort. The required interactions between the surgeon and the technical components, such as neuronavigation, surgical instruments and intraoperative imaging, are complex and demand innovative training solutions and standardized evaluation methods. Phantom-based training systems could be useful in complementing the existing surgical education and training.

METHODS

A prototype of a phantom-based training system was developed, intended for standardized training of important aspects of brain tumor surgery based on real patient data. The head phantom consists of a three-part construction that includes a reusable base and adapter, as well as a changeable module for single use. Training covers surgical planning of the optimal access path, the setup of the navigation system including the registration of the head phantom, as well as the navigated craniotomy with real instruments. Tracked instruments during the simulation and predefined access paths constitute the basis for the essential objective training feedback.

RESULTS

The prototype was evaluated in a pilot study by assistant physicians at different education levels. They performed a complete simulation and a final assessment using an evaluation questionnaire. The analysis of the questionnaire showed the evaluation result as "good" for the phantom construction and the used materials. The learning effect concerning the navigated planning was evaluated as "very good", as well as having the effect of increasing safety for the surgeon before planning and conducting craniotomies independently on patients.

CONCLUSIONS

The training system represents a promising approach for the future training of neurosurgeons. It aims to improve surgical skill training by creating a more realistic simulation in a non-risk environment. Hence, it could help to bridge the gap between theoretical and practical training with the potential to benefit both physicians and patients.

History of simulation in medicine: from Resusci Annie to the Ann Myers Medical Center

Medical and surgical graduate medical education has historically used a halstedian approach of "see one, do one, teach one." Increased public demand for safety, quality, and accountability in the setting of regulated resident work hours and limited resources is driving the development of innovative educational tools. The use of simulation in nonmedical, medical, and neurosurgical disciplines is reviewed in this article. Simulation has been validated as an educational tool in nonmedical fields such as aviation and the military. Across most medical and surgical subspecialties, simulation is recognized as a valuable tool that will shape the next era of medical education, postgraduate training, and maintenance of certification.

Effects of transesophageal echocardiography simulator training on learning and performance in cardiovascular medicine fellows

BACKGROUND

The role of transesophageal echocardiography (TEE) simulation in cardiology fellows' learning is unknown. Standard TEE training at the authors' institution occurs during the second of 3 clinical years. Fellows spend 2 months in the TEE laboratory learning through hands-on experience. The addition of TEE simulation to this experience may improve proficiency, speed learning, and increase fellows' comfort with TEE. This study was designed to compare methods of TEE simulator training with standard training.

METHODS

Group A (n = 8) consisted of fellows who had completed standard TEE training. Fellows starting their second clinical year were randomly assigned to group B (n = 10), simulator training during month 1, or group C (n = 9), simulator training during month 2. All groups completed 2 months of standard TEE training. All groups underwent assessment of TEE performance and a self-assessment of ability and comfort level with TEE.

RESULTS

Groups B and C had higher total assessment scores than group A. Groups B and C had higher numbers of views achieved without assistance (P = .01). After month 1, group B had higher total scores and number of views achieved without assistance compared with group C (P = .02 and P = .02, respectively). The length of time of the examination tended to be lower for group B, and fellows in group B had greater comfort with TEE than those in group C (P = .01).

CONCLUSIONS

These data suggest that TEE simulator training improves proficiency and helps speed learning and comfort with TEE.

Design of a synthetic simulator for pediatric lumbar spine pathologies

OBJECT

Simulation has become an important tool in neurosurgical education as part of the complex process of improving residents' technical expertise while preserving patient safety. Although different simulators have already been designed for a variety of neurosurgical procedures, spine simulators are still in their infancy and, at present, there is no available simulator for lumbar spine pathologies in pediatric neurosurgery. In this paper the authors describe the peculiarities and challenges involved in developing a synthetic simulator for pediatric lumbar spine pathologies, including tethered spinal cord syndrome and open neural tube defects.

METHODS

The Department of Neurosurgery of the University of Illinois at Peoria, in a joint program with the Mechanical Engineering Department of Bradley University, designed and developed a general synthetic model for simulating pediatric neurosurgical interventions on the lumbar spine. The model was designed to be composed of several sequential layers, so that each layer might closely mimic the tensile properties of the natural tissues under simulation. Additionally, a system for pressure monitoring was developed to enable precise measurements of the degree of manipulation of the spinal cord.

RESULTS

The designed prototype successfully simulated several scenarios commonly found in pediatric neurosurgery, such as tethered spinal cord, retethered spinal cord, and fatty terminal filum, as well as meningocele, myelomeningocele, and lipomyelomeningocele. Additionally, the formulated grading system was able to account for several variables involved in the qualitative evaluation of the technical performance during the training sessions and, in association with an expert qualitative analysis of the recorded sessions, proved to be a useful feedback tool for the trainees.

CONCLUSIONS

Designing and building a synthetic simulator for pediatric lumbar spine pathologies poses a wide variety of unique challenges. According to the authors' experience, a modular system composed of separable layers that can be independently replaced significantly enhances the applicability of such a model, enabling its individualization to distinctive but interrelated pathologies. Moreover, the design of a system for pressure monitoring (as well as a general score that may be able to account for the overall technical quality of the trainee's performance) may further enhance the educational applications of a simulator of this kind so that it can be further incorporated into the neurosurgical residency curriculum for training and evaluation purposes.

Virtual reality simulation: basic concepts and use in endoscopic neurosurgery training

INTRODUCTION

Virtual reality simulation is a promising alternative to training surgical residents outside the operating room. It is also a useful aide to anatomic study, residency training, surgical rehearsal, credentialing, and recertification.

DISCUSSION

Surgical simulation is based on a virtual reality with varying degrees of immersion and realism. Simulators provide a no-risk environment for harmless and repeatable practice. Virtual reality has three main components of simulation: graphics/volume rendering, model behavior/tissue deformation, and haptic feedback. The challenge of accurately simulating the forces and tactile sensations experienced in neurosurgery limits the sophistication of a virtual simulator. The limited haptic feedback available in minimally invasive neurosurgery makes it a favorable subject for simulation.

CONCLUSIONS

Virtual simulators with realistic graphics and force feedback have been developed for ventriculostomy, intraventricular surgery, and transsphenoidal pituitary surgery, thus allowing preoperative study of the individual anatomy and increasing the safety of the procedure. The authors also present experiences with their own virtual simulation of endoscopic third ventriculostomy.

Interactive presurgical simulation applying advanced 3D imaging and modeling techniques for skull base and deep tumors

Object

In this paper, the authors' goal was to report their novel presurgical simulation method applying interactive virtual simulation (IVS) using 3D computer graphics (CG) data and microscopic observation of color-printed plaster models based on these CG data in surgery for skull base and deep tumors.

Methods

For 25 operations in 23 patients with skull base or deep intracranial tumors (meningiomas, schwannomas, epidermoid tumors, chordomas, and others), the authors carried out presurgical simulation based on 3D CG data created by image analysis for radiological data. Interactive virtual simulation was performed by modifying the 3D CG data to imitate various surgical procedures, such as bone drilling, brain retraction, and tumor removal, with manipulation of a haptic device. The authors also produced color-printed plaster models of modified 3D CG data by a selective laser sintering method and observed them under the operative microscope.

Results

In all patients, IVS provided detailed and realistic surgical perspectives of sufficient quality, thereby allowing surgeons to determine an appropriate and feasible surgical approach. Surgeons agreed that in 44% of the 25 operations IVS showed high utility (as indicated by a rating of “prominent”) in comprehending 3D microsurgical anatomies for which reconstruction using only 2D images was complicated. Microscopic observation of color-printed plaster models in 12 patients provided further utility in confirming realistic surgical anatomies.

Conclusions

The authors' presurgical simulation method applying advanced 3D imaging and modeling techniques provided a realistic environment for practicing microsurgical procedures virtually and enabled the authors to ascertain complex microsurgical anatomy, to determine the optimal surgical strategies, and also to efficiently educate neurosurgical trainees, especially during surgery for skull base and deep tumors.