Development of a modelled anatomical replica for training young neurosurgeons

Developing a piezoresistive sensor based bionic neurological intraoperative monitoring system for spine surgery skill training

This research aims to tackle the limitations faced in surgical education nowadays, particularly in the complex field of spinal cord tumor removal surgery. An innovative flexible piezoresistive sensor designed to mimic a motor nerve was developed and integrated into a bionic spine surgery simulation system, allowing for the intraoperative nerve monitoring possible during simulated tumor removal surgeries. The motor nerve, fabricated using a combination of carbon nanotubes and silicone rubber, exhibited a strong correlation between applied force and resultant changes in resistance, as confirmed by experimental results. This creative system can play an important role in providing valuable feedback for training doctors, facilitating the assessment of surgical precision and success, and enabling doctors to take necessary precautions to minimize the risk of nerve damage in real surgical scenarios. Ultimately, this proposed system has the potential to elevate the standard of surgical education, foster skill development among doctors, and significantly contribute to enhanced patient care and recovery.

External Ventricular Drain Training in Medical Students Improves Procedural Accuracy and Attitudes Toward Virtual Reality

OBJECTIVE

Neurosurgery residents face a learning curve at the beginning of residency. Virtual reality (VR) training may alleviate challenges through an accessible, reusable, anatomical model.

METHODS

Medical students performed external ventricular drain placements in VR to characterize the learning curve from novice to proficient. Distance from catheter to foramen of Monro and location with respect to ventricle were recorded. Changes in attitudes toward VR were assessed. Neurosurgery residents performed external ventricular drain placements to validate proficiency benchmarks. Resident and student impressions of the VR model were compared.

RESULTS

Twenty-one students with no neurosurgical experience and 8 neurosurgery residents participated. Student performance improved significantly from trial 1 to 3 (15 mm [12.1-20.70] vs. 9.7 [5.8-15.3], P = 0.02). Student attitudes regarding VR utility improved significantly posttrial. The distance to foramen of Monro was significantly shorter for residents than for students in trial 1 (9.05 [8.25-10.73] vs. 15 [12.1-20.70], P = 0.007) and trial 2 (7.45 [6.43-8.3] vs. 19.5 [10.9-27.6], P = 0.002). By trial 3 there was no significant difference (10.1 [8.63-10.95 vs. 9.7 [5.8-15.3], P = 0.62). Residents and students provided similarly positive feedback for VR in resident curricula, patient consent, preoperative practice and planning. Residents provided more neutral-to-negative feedback regarding skill development, model fidelity, instrument movement, and haptic feedback.

CONCLUSIONS

Students showed significant improvement in procedural efficacy which may simulate resident experiential learning. Improvements in fidelity are needed before VR can become a preferred training technique in neurosurgery.

Overcoming Barriers in Neurosurgical Education: A Novel Approach to Practical Ventriculostomy Simulation

BACKGROUND

In the high-risk, high-stakes specialty of neurosurgery, traditional teaching methods often fail to provide young residents with the proficiency needed to perform complex procedures in stressful situations, with direct effects on patient outcomes. Physical simulators provide the freedom of focused, hands-on training in a more controlled environment. However, the adoption of simulators in neurosurgical training remains a challenge because of high acquisition costs, complex production processes, and lack of realism.

OBJECTIVE

To introduce an easily reproducible, cost-effective simulator for external ventricular drain placements through various ventriculostomy approaches with life-like tactile brain characteristics based on real patients' data.

METHODS

Whole brain and skull reconstruction from patient's computed tomography and MRI data were achieved using freeware and a desktop 3-dimensional printer. Subsequently, a negative brain silicone mold was created. Based on neurosurgical expertise and rheological measurements of brain tissue, gelatin in various concentrations was tested to cast tactilely realistic brain simulants. A sample group of 16 neurosurgeons and medical students tested and evaluated the simulator in respect to realism, haptics, and general usage, scored on a 5-point Likert scale.

RESULTS

We saw a rapid and significant improvement of accuracy among novice medical students. All participants deemed the simulator as highly realistic, effective, and superior to conventional training methods.

CONCLUSION

We were able to demonstrate that building and implementing a high-fidelity simulator for one of the most important neurosurgical procedures as an effective educational and training tool is achievable in a timely manner and without extensive investments.

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.

Simulation for skills training in neurosurgery: a systematic review, meta-analysis, and analysis of progressive scholarly acceptance

At a time of significant global unrest and uncertainty surrounding how the delivery of clinical training will unfold over the coming years, we offer a systematic review, meta-analysis, and bibliometric analysis of global studies showing the crucial role simulation will play in training. Our aim was to determine the types of simulators in use, their effectiveness in improving clinical skills, and whether we have reached a point of global acceptance. A PRISMA-guided global systematic review of the neurosurgical simulators available, a meta-analysis of their effectiveness, and an extended analysis of their progressive scholarly acceptance on studies meeting our inclusion criteria of simulation in neurosurgical education were performed. Improvement in procedural knowledge and technical skills was evaluated. Of the identified 7405 studies, 56 studies met the inclusion criteria, collectively reporting 50 simulator types ranging from cadaveric, low-fidelity, and part-task to virtual reality (VR) simulators. In all, 32 studies were included in the meta-analysis, including 7 randomised controlled trials. A random effects, ratio of means effects measure quantified statistically significant improvement in procedural knowledge by 50.2% (ES 0.502; CI 0.355; 0.649, p < 0.001), technical skill including accuracy by 32.5% (ES 0.325; CI - 0.482; - 0.167, p < 0.001), and speed by 25% (ES - 0.25, CI - 0.399; - 0.107, p < 0.001). The initial number of VR studies (n = 91) was approximately double the number of refining studies (n = 45) indicating it is yet to reach progressive scholarly acceptance. There is strong evidence for a beneficial impact of adopting simulation in the improvement of procedural knowledge and technical skill. We show a growing trend towards the adoption of neurosurgical simulators, although we have not fully gained progressive scholarly acceptance for VR-based simulation technologies in neurosurgical education.

Multilayered Artificial Dura-Mater Models for a Minimally Invasive Brain Surgery Simulator

In this study, new artificial dura-mater models were developed using a multilayered structure of a rubber material (represent an elastic component of a dura-mater) and a fiber sheet (represent fiber component of a dura-mater). The artificial dura-mater models were prepared for use in a brain surgery simulator, especially for transnasal pituitary surgery. The mechanical characteristics of the artificial dura-mater models were tested to check the similarities with porcine dura-mater. Tensile stress, viscoelasticity, and the cutting force generated by microscissors were tested to evaluate the fabricated models. Neurosurgeons also assessed the dura-mater models to evaluate their characteristics. The results indicate that these models made of two different non-woven fiber sheets emulated accurately the actual dura-mater.

Neurosurgical simulator for training aneurysm microsurgery-a user suitability study involving neurosurgeons and residents

BACKGROUND

Due to its complexity and to existing treatment alternatives, exposure to intracranial aneurysm microsurgery at the time of neurosurgical residency is limited. The current state of the art includes training methods like assisting in surgeries, operating under supervision, and video training. These approaches are labor-intensive and difficult to fit into a timetable limited by the new work regulations. Existing virtual reality (VR)-based training modules lack patient-specific exercises and haptic properties and are thus inferior to hands-on training sessions and exposure to real surgical procedures.

MATERIALS AND METHODS

We developed a physical simulator able to reproduce the experience of clipping an intracranial aneurysm based on a patient-specific 3D-printed model of the skull, brain, and arteries. The simulator is made of materials that not only imitate tissue properties including arterial wall patency, thickness, and elasticity but also able to recreate a pulsatile blood flow. A sample group of 25 neurosurgeons and residents (n = 16: early residency with less than 4 years of neurosurgical exposure; n = 9: late residency and board-certified neurosurgeons, 4-15 years of neurosurgical exposure) took part to the study. Participants evaluated the simulator and were asked to answer questions about surgical simulation anatomy, realism, haptics, tactility, and general usage, scored on a 5-point Likert scale. In order to evaluate the feasibility of a future validation study on the role of the simulator in neurosurgical postgraduate training, an expert neurosurgeon assessed participants' clipping performance and a comparison between groups was done.

RESULTS

The proposed simulator is reliable and potentially useful for training neurosurgical residents and board-certified neurosurgeons. A large majority of participants (84%) found it a better alternative than conventional neurosurgical training methods.

CONCLUSION

The integration of a new surgical simulator including blood circulation and pulsatility should be considered as part of the future armamentarium of postgraduate education aimed to ensure high training standards for current and future generations of neurosurgeons involved in intracranial aneurysm surgery.

Development and initial evaluation of a novel simulation model for comprehensive brain tumor surgery training

Background

Increasing technico-manual complexity of procedures and time constraints necessitates effective neurosurgical training. For this purpose, both screen- and model-based simulations are under investigation. Approaches including 3D printed brains, gelatin composite models, and virtual environments have already been published. However, quality of brain surgery simulation is limited due to discrepancies in visual and haptic experience. Similarly, virtual training scenarios are still lacking sufficient real-world resemblance. In this study, we introduce a novel simulator for realistic neurosurgical training that combines real brain tissue with 3D printing and augmented reality.

Methods

Based on a human CT scan, a skull base and skullcap were 3D printed and equipped with an artificial dura mater. The cerebral hemispheres of a calf’s brain were placed in the convexity of the skullcap and tumor masses composed of aspic, water, and fluorescein were injected in the brain. The skullcap and skull base were placed on each other, glued together, and filled up with an aspic water solution for brain fixation. Then, four surgical scenarios were performed in the operating room as follows: (1) simple tumor resection, (2) complex tumor resection, (3) navigated biopsy via burr hole trepanation, and (4) retrosigmoidal craniotomy. Neuronavigation, augmented reality, fluorescence, and ocular—as well as screen-based (exoscopic)—surgery were available for the simulator training. A total of 29 participants performed at least one training scenario of the simulator and completed a 5-item Likert-like questionnaire as well as qualitative interviews. The questionnaire assessed the realism of the tumor model, skull, and brain tissue as well as the capability for training purposes.

Results

Visual and sensory realism of the skull and brain tissue were rated,”very good,” while the sensory and visual realism of the tumor model were rated “good.” Both overall satisfaction with the model and eligibility of the microscope and neurosurgical instruments for training purposes were rated with “very good.” However, small size of the calf’s brain, its limited shelf life, and the inability to simulate bleedings due to the lack of perfusion were significant drawbacks.

Conclusion

The combination of 3D printing and real brain tissue provided surgical scenarios with very good real-life resemblance. This novel neurosurgical model features a versatile setup for surgical skill training and allows for efficient training of technological support like image and fluorescence guidance, exoscopic surgery, and robotic technology.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04359-w) contains supplementary material, which is available to authorized users.

Patient-Specific Polyvinyl Alcohol Phantom Fabrication with Ultrasound and X-Ray Contrast for Brain Tumor Surgery Planning

Phantoms are essential tools for clinical training, surgical planning and the development of novel medical devices. However, it is challenging to create anatomically accurate head phantoms with realistic brain imaging properties because standard fabrication methods are not optimized to replicate any patient-specific anatomical detail and 3D printing materials are not optimized for imaging properties. In order to test and validate a novel navigation system for use during brain tumor surgery, an anatomically accurate phantom with realistic imaging and mechanical properties was required. Therefore, a phantom was developed using real patient data as input and 3D printing of molds to fabricate a patient-specific head phantom comprising the skull, brain and tumor with both ultrasound and X-ray contrast. The phantom also had mechanical properties that allowed the phantom tissue to be manipulated in a similar manner to how human brain tissue is handled during surgery. The phantom was successfully tested during a surgical simulation in a virtual operating room.

The phantom fabrication method uses commercially available materials and is easy to reproduce. The 3D printing files can be readily shared, and the technique can be adapted to encompass many different types of tumor.

Development and Validation of a Mobile Device-based External Ventricular Drain Simulator

BACKGROUND

Multiple external ventricular drain (EVD) simulators have been created, yet their cost, bulky size, and nonreusable components limit their accessibility to residency programs.

OBJECTIVE

To create and validate an animated EVD simulator that is accessible on a mobile device.

METHODS

We developed a mobile-based EVD simulator that is compatible with iOS (Apple Inc., Cupertino, California) and Android-based devices (Google, Mountain View, California) and can be downloaded from the Apple App and Google Play Store. Our simulator consists of a learn mode, which teaches users the procedure, and a test mode, which assesses users' procedural knowledge. Twenty-eight participants, who were divided into expert and novice categories, completed the simulator in test mode and answered a postmodule survey. This was graded using a 5-point Likert scale, with 5 representing the highest score. Using the survey results, we assessed the module's face and content validity, whereas construct validity was evaluated by comparing the expert and novice test scores.

RESULTS

Participants rated individual survey questions pertaining to face and content validity a median score of 4 out of 5. When comparing test scores, generated by the participants completing the test mode, the experts scored higher than the novices (mean, 71.5; 95% confidence interval, 69.2 to 73.8 vs mean, 48; 95% confidence interval, 44.2 to 51.6; P < .001).

CONCLUSION

We created a mobile-based EVD simulator that is inexpensive, reusable, and accessible. Our results demonstrate that this simulator is face, content, and construct valid.

Developing a pediatric neurosurgical training model

OBJECTIVE One of the greatest challenges of pediatric neurosurgery training is balancing the training needs of the trainee against patient safety and parental expectation. The traditional "see one, do one, teach one" approach to training is no longer acceptable in pediatric neurosurgery. The authors have developed the baby Modeled Anatomical Replica for Training Young Neurosurgeons (babyMARTYN). The development of this new training model is described, its feasibility as a training tool is tested, and a new approach of integrating simulation into day-to-day training is suggested. METHODS In part 1 (development), a prototype skull was developed using novel model-making methods. In part 2 (validation), 18 trainee neurosurgeons (at various stages in training) performed the following 4 different procedures: 1) evacuation of a posterior fossa hematoma; 2) pterional craniotomy; 3) tapping of the fontanelle to obtain a CSF specimen; and 4) external ventricular drain insertion. Completion of the procedural stages (scored using a curriculum-based checklist) was used to test the feasibility of babyMARTYN as a training tool. Likert scale-based questionnaires were used to assess the model for face and content validity. Training benefit was assessed using pre- and posttraining ratings on the Physician Performance Diagnostic Inventory Scale (PPDIS). To determine the significance of improvement in median PPDIS score, the Wilcoxon matched-pairs signed-rank test was performed. RESULTS In part 1 (development), the model was successfully developed with good fidelity. In part 2 (validation), the validation data demonstrated feasibility, face, and content validity. The PPDIS score significantly increased for all groups after babyMARTYN training, thereby indicating a potential future role for babyMARTYN in the training of pediatric neurosurgeons. CONCLUSIONS This recent collaborative neurosurgical development by the Royal College of Surgeons of England is designed to supplement current neurosurgical training. High-fidelity, portable, operation-specific models enable preoperative planning and have the potential to be used in an operating room environment prior to novel operations. A "see one, simulate one, do one" approach for pediatric neurosurgical training using babyMARTYN is suggested.

Simulation in neurosurgical training: a blueprint and national approach to implementation for initial years trainees

Simulation has played an increasing role in surgical training in recent years, this follows from various reports such as the Chief Medical Officer annual report and Sir John Temple's 'Time for Training' and also from other factors such as increasing focus on efficiency and transparency within the healthcare system. Evidence has shown that simulation can develop and improve technical, clinical, communication and management skills. With technological advances, the quality of simulation has also improved with more realistic models and environment. We have undertaken a review of recent drivers for simulation training in the UK, current techniques and have focused on the application of simulation training within the current UK Neurosurgical curriculum for newly appointed trainees.