Design and validation of a hemispherectomy simulator for neurosurgical education.

OBJECTIVE: Early adaptors of surgical simulation have documented a translation to improved intraoperative surgical performance. Similar progress would boost neurosurgical education, especially in highly nuanced epilepsy surgeries. This study introduces a hands-on cerebral hemispheric surgery simulator and evaluates its usefulness in teaching epilepsy surgeries. METHODS: Initially, the anatomical realism of the simulator and its perceived effectiveness as a training tool were evaluated by two epilepsy neurosurgeons. The surgeons independently simulated hemispherotomy procedures and provided questionnaire feedback. Both surgeons agreed on the anatomical realism and effectiveness of this training tool. Next, construct validity was evaluated by modeling the proficiency (task-completion time) of 13 participants, who spanned the experience range from novice to expert. RESULTS: Poisson regression yielded a significant whole-model fit (χ2 = 30.11, p < 0.0001). The association between proficiency when using the training tool and the combined effect of prior exposure to hemispherotomy surgery and career span was statistically significant (χ2 = 7.30, p = 0.007); in isolation, pre-simulation exposure to hemispherotomy surgery (χ2 = 6.71, p = 0.009) and career length (χ2 = 14.21, p < 0.001) were also significant. The mean (± SD) task-completion time was 25.59 ± 9.75 minutes. Plotting career length against task-completion time provided insights on learning curves of epilepsy surgery. Prediction formulae estimated that 10 real-life hemispherotomy cases would be needed to approach the proficiency seen in experts. CONCLUSIONS: The cerebral hemispheric surgery simulator is a reasonable epilepsy surgery training tool in the quest to increase preoperative practice opportunities for neurosurgical education.

Moderate procedural confidence improvement following hands-on practice using the hemispherectomy simulator.

INTRODUCTION: Pediatric hemispherectomy is a technically demanding procedure with significant risk. There are relatively few opportunities for surgeon trainees to gain confidence in this nuanced surgery solely through traditional apprenticeship prior to independent practice. Surgeon confidence has been linked to better intraoperative performance and surgical simulation has, according to literature, resulted in improved surgeon confidence. This manuscript measures the effect of epilepsy simulation on the procedural confidence of neurosurgical trainees as a marker of future improved intraoperative performance. METHODS: Eleven neurosurgery residents and fellows were allowed to practice on a novel hemispherectomy simulator. Pre- and post-simulation procedural confidence was measured using a 10-item questionnaire, with total scores ranging from 10 (least confident) to 50 (most confident). Matched pair t-testing was performed to determine participant mean difference between the pre- and post-procedural data sets. RESULTS: The assessment tool bore a high reliability coefficient (Cronbach's α = 0.93). The procedural confidence of all the study participants increased following simulation (p value < 0.001). The overall mean increase in confidence was 7.2 ± 4.0 (mean ± standard deviation), 7.5 ± 4.7 among fellows and 6.8 ± 3.6 among residents. Procedural confidence values were higher among the fellows (26.9 ± 8.1) compared to the residents (19.0 ± 7.4). This difference in means was statistically significant (p value 0.03). A positive association was calculated between the perceived confidence and the postgraduate year of training (p value 0.005, r = 0.57). CONCLUSION: The hemispherectomy simulator moderately improves perceived confidence among neurosurgical trainees and may augment pre-operative surgical practice opportunities.

Associating Surgeon Feedback With Material Physical Properties in the Development Process of a Resective Epilepsy Surgery Simulator.

BACKGROUND: Hands-on neurosurgical simulations, specifically techniques involving white matter disconnection, are underdeveloped owing to the paucity of low indentation materials that can adequately mimic brain dissection. OBJECTIVE: To describe the discovery phase of developing a resective epilepsy surgery simulator by quantifying the physical properties of 6 materials and correlating the scores with surgeon feedback data. METHODS: Six materials, silicone, TissueMatrix, gel support, Synaptive hydrogel, dry SUP706, and moist SUP706 of equal dimension, were evaluated for hardness by measuring their resistance to indentation. Temporal lobe prototypes, 1 for each material, were dissected by 2 neurosurgeons and ordinal ranking assigned. Two null hypotheses were tested: one is that no differences in the indentation properties of the 6 materials analyzed would be elicited and the other is that there would be no correlation between indentation and surgeon feedback scores. Statistical comparison of the means of the different materials was performed using one-way analysis of variance. Surgeon feedback data and indentation score associations were analyzed using the Kendall rank correlation coefficient. RESULTS: A statistically significant effect (P value <.0001; α 0.05) was measured. Gel support and Synaptive hydrogel had the lowest indentation scores and similar physical properties. Moist support material scored lower than dry support (P = .0067). A strong positive correlation (Kendall tau = 0.9333, P < .0001) was ascertained between the surgeon feedback ranking and indentation scores. CONCLUSION: Reasonable material options for developing a resective epilepsy surgery are proposed and ranked in this article. Early involvement of surgeons is useful in the discovery phase of simulator invention.

A simulation study to investigate the use of concentric tube robots for epilepsy surgery.

PURPOSE: Patients with pharmacoresistant refractory epilepsy may require epilepsy surgery to prevent future seizure occurrences. Conventional surgery consists of a large craniotomy with straight rigid tools with associated outcomes of morbidity, large tissue resections, and long post-operative recovery times. Concentric tube robots have recently been developed as a promising application to neurosurgery due to their nonlinear form and small diameter. The authors present a concept study to explore the feasibility of performing minimally invasive hemispherotomy with concentric tube robots. METHODS: A model simulation was used to achieve the optimal design and surgical path planning parameters of the concentric tube robot for corpus callosotomy and temporal lobectomy. A single medial burr hole was chosen to access the lateral ventricles for both white matter disconnections. RESULTS: The concentric tube robot was able to accurately reach the designated surgical paths on the corpus callosum and the temporal lobe. CONCLUSION: In a model simulation, the authors demonstrated the feasibility of performing corpus callosotomy and temporal lobectomy using concentric tube robots. Further advancements in the technology may increase the applicability of this technique for epilepsy surgery to better patient outcomes.

Application of 3D Printing Support Material for Neurosurgical Simulation.

Brain dissection, an intricate neurosurgical skill, is central to life-saving procedures such as intrinsic brain tumor excision and resective epilepsy surgery. The aims of this manuscript are to outline the selection process of a suitable material for the development of a dissectible brain simulator and to present the use of support material, SUP 706, manufactured by Stratasys Ltd. as a non-waste alternative for sustainably engineering solutions for surgical education. A feasibility study was conducted through qualitative function deployment (QFD) followed by a material selection process. End-user requirements and manufacturing product characteristics were incorporated into the workflow. Three materials, silicone, TissueMatrix™ and support material each formed the primary component of the first two prototypes. Expert feedback, manufacturing cost, safety profiling, functional fidelity and post-processing time data were collected and analyzed. The unique break-away feature of moist support material was found to be more suitable than using silicone or TissueMatrix™ for demonstrating brain dissection techniques. In addition, support material displayed higher functional fidelity by mimicking surgical tissues such as pia mater, gray and white matter, and blood vessels. The cost of the support material prototype was 39% less that of TissueMatrix™ and roughly the same as the silicone model. It took twice as long to post-process the support material prototype than it did the TissueMatrix™ design. Support material lost its ideal dissection properties and began to disintegrate after 30 - 45 minutes. In conclusion 3D printer support material is a low-cost material for a dissectible brain simulator.Clinical Relevance- The use of support material as the primary material in developing a dissectible brain simulator is a promising way of advancing neurosurgical education.

3D printing in neurosurgery education: a review.

OBJECTIVES: The objectives of this manuscript were to review the literature concerning 3D printing of brain and cranial vault pathology and use these data to define the gaps in global utilization of 3D printing technology for neurosurgical education. METHODS: Using specified criteria, literature searching was conducted to identify publications describing engineered neurosurgical simulators. Included in the study were manuscripts highlighting designs validated for neurosurgical skill transfer. Purely anatomical designs, lacking aspects of surgical simulation, were excluded. Eligible manuscripts were analyzed. Data on the types of simulators, representing the various modelled neurosurgical pathologies, were recorded. Authors' countries of affiliation were also recorded. RESULTS: A total of thirty-six articles, representing ten countries in five continents were identified. Geographically, Africa as a continent was not represented in any of the publications. The simulation-modelling encompassed a variety of neurosurgical subspecialties including: vascular, skull base, ventriculoscopy / ventriculostomy, craniosynostosis, skull lesions / skull defects, intrinsic brain tumor and other. Finally, the vascular and skull base categories together accounted for over half (52.8 %) of the 3D printed simulated neurosurgical pathology. CONCLUSIONS: Despite the growing body of literature supporting 3D printing in neurosurgical education, its full potential has not been maximized. Unexplored areas of 3D printing for neurosurgical simulation include models simulating the resection of intrinsic brain tumors or of epilepsy surgery lesions, as these require complex models to accurately simulate fine dissection techniques. 3D printed surgical phantoms offer an avenue for the advancement of global-surgery education initiatives.

Digital Twin Technology: The Future of Predicting Neurological Complications of Pediatric Cancers and Their Treatment.

Healthcare technologies have seen a surge in utilization during the COVID 19 pandemic. Remote patient care, virtual follow-up and other forms of futurism will likely see further adaptation both as a preparational strategy for future pandemics and due to the inevitable evolution of artificial intelligence. This manuscript theorizes the healthcare applications of digital twin technology. Digital twin is a triune concept that involves a physical model, a virtual counterpart, and the interplay between the two constructs. This interface between computer science and medicine is a new frontier with broad potential applications. We propose that digital twin technology can exhaustively and methodologically analyze the associations between a physical cancer patient and a corresponding digital counterpart with the goal of isolating predictors of neurological sequalae of disease. This proposition stems from the premise that data science can complement clinical acumen to scientifically inform the diagnostics, treatment planning and prognostication of cancer care. Specifically, digital twin could predict neurological complications through its utilization in precision medicine, modelling cancer care and treatment, predictive analytics and machine learning, and in consolidating various spectra of clinician opinions.

Hydranencephaly treatments: retrospective case series and review of the literature.

OBJECTIVE: The objective of this study was to review treatment options for infants with hydranencephaly and to consider the pros and cons of each treatment modality. METHODS: This paper is a review of hydranencephaly as well as a retrospective analysis evaluating the outcomes of 52 infants with hydranencephaly who were treated at the Kijabe Hospital, Kijabe, Kenya, in one of four ways: ventriculoperitoneal shunt (VPS) insertion, endoscopic choroid plexus coagulation (CPC), open choroid plexectomy (CPlx), and palliative care. The primary outcome measure was control of head size, with the aim of improving patient care. One-year mortality was a secondary outcome. RESULTS: Of the 52 patients analyzed, 11 underwent VPS insertion, 17 CPC, 14 CPlx, and 10 were treated palliatively. Head size was controlled at the 3-month evaluation interval in 5 of 7 infants treated with VPS, 10 of 16 of those treated with CPC, 6 of 9 of those treated with CPlx, and 1 of 4 treated palliatively. The number of infants in each category with complete follow-up data that were needed to analyze change in head size was lower than the total number of patients included in each category. Mortality at 1 year of age was 9 of 11 in the VPS group, 14 of 17 in the CPC group, 6 of 14 in the CPlx group, and 7 of 10 in the palliative group. CONCLUSIONS: Head size decreased by 1 cm or more in similar proportions (62%-71%) of infants with hydranencephaly who were treated by VPS insertion, CPC, and CPlx, and progressed in those who received palliative care. Mortality at 1 year of age was similar in infants treated by a VPS, CPC, and palliative care (70%-82%), but lower (43%) in those treated with CPlx.

Pediatric Neurosurgery in East Africa: An Education and Needs-Based Survey.

INTRODUCTION: A pediatric neurosurgery training workshop was organized for residents and consultants in East Africa. We aimed to compile feedback from the course participants to 1) characterize the state of neurosurgical education; and 2) identify the perceived practical education needs. METHODS: The survey of demographic, clinical background and practice, and feedback questions was distributed to all attendees. Responses were elicited via yes/no questions and Likert scales, with the score ranging from 1 (not important, not useful, never) to 5 (very important, very useful, often). The data were de-identified and analyzed in aggregate. RESULTS: A total of 11 neurosurgeons and trainees completed the survey, including 6 residents (55%) and 5 consultants (45%). Although 5 countries of origin were represented, all attendees (100%) have completed their neurosurgery training in Kenya. The respondents had most frequently treated trauma (least common to most common, 1-5; mean, 4.55 ± 0.93), hemorrhagic stroke (mean, 4.27 ± 0.79), and pediatric tumors (mean, 4.27 ± 1.01). In training, the most commonly used study resources were online resources (9; 82%), textbooks (7; 64%), and online lectures (7; 64%). The areas of greatest perceived need in education and training included general neurosurgery (least to most need, 1-10: 9; 82%), pediatric (9; 82%), trauma and neurocritical care (7; 64%), and neuro-oncology (7; 64%). All 11 respondents (100%) reported that more direct operative teaching was important for educational improvement. Hydrocephalus (least to most useful, 1-5: 5.00 ± 0.00), neuro-endoscopy (4.91 ± 0.30), and tumor (4.91 ± 0.30) were considered the most useful content covered in the pediatric neurosurgery-focused training program to improve skills and knowledge base. CONCLUSIONS: The results from the present survey identified areas of education and training needs to guide further neurosurgical education efforts in East Africa.

Multiple hippocampal transections: Post-operative Memory Outcomes and Seizure Control.

OBJECT: Temporal lobectomy with amygdalohippocampectomy is the standard surgical treatment for appropriate candidates with medically-intractable temporal lobe epilepsy. More recently, because of the risk of postoperative language/memory decline in a subset of patients with intact memory, a multiple hippocampal transection (MHT) approach has been proposed to preserve function. METHODS: Studies of MHT reporting both Engel and verbal memory outcome measures were included in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting of systematic reviews. Data were extracted on verbal memory function pre- and postoperatively, seizure outcome, and demographic factors. A random effects model was used to determine overall verbal memory function after MHT, and a meta-regression model was applied to identify factors associated with outcome. RESULTS: A total of 114 patients across five studies were included. Engel class I seizure outcome across all studies ranged from 64.7% to 94.7%, with 84 of the 114 patients achieving this outcome. Preoperative verbal memory score was most strongly associated with postoperative verbal memory preservation (p = 0.003). Of 59 patients with full verbal memory outcome scores, 86.8% (95% CI [confidence interval]: 77.6%-96%) had complete preservation of verbal memory relative to preoperative functional baseline. CONCLUSION: Multiple hippocampal transection is an evolving surgical technique. Although the present data are limited, the current systematic review suggests that this approach is effective at preserving verbal memory in patients with good baseline function. Although reasonable seizure outcomes have been reported with MHT, comparison to a well-established procedure such as temporal lobectomy and amydalohippocampectomy must be guided by further evidence.