The Integration of 3D Virtual Reality and 3D Printing Technology as Innovative Approaches to Preoperative Planning in Neuro-Oncology

Our study explores the integration of three-dimensional (3D) virtual reality (VR) and 3D printing in neurosurgical preoperative planning. Traditionally, surgeons relied on two-dimensional (2D) imaging for complex neuroanatomy analyses, requiring significant mental visualization. Fortunately, nowadays advanced technology enables the creation of detailed 3D models from patient scans, utilizing different software. Afterwards, these models can be experienced through VR systems, offering comprehensive preoperative rehearsal opportunities. Additionally, 3D models can be 3D printed for hands-on training, therefore enhancing surgical preparedness. This technological integration transforms the paradigm of neurosurgical planning, ensuring safer procedures.

Development of a Standardized Semantic Feature-Based Reporting Proforma for Intraoperative Ultrasound Findings in Brain Tumors and Application in High-Grade Gliomas - A Preliminary Study

Purpose A semantic feature-based reporting proforma for intraoperative ultrasound findings in brain tumors was devised to standardize reporting. It was applied as a pilot study on a cohort of histologically confirmed high-grade supratentorial gliomas (Grade 3 and 4) for internal validation.

Materials and Methods This intraoperative semantic ultrasound proforma was used to evaluate 3D ultrasound volumes using Radiant DICOM software by 3 surgeons. The ultrasound semantic features were correlated with histological features like tumor grade, IDH status, and MIB index.

Results 68 patients were analyzed using the semantic proforma. Irregular crenated was the most common margin (63.2%) and lesions were heterogeneously hyperechoic (95.6%). Necrosis was commonly seen and noted as single (67.6%) or multiple (13.2%) in over 80% cases. A separate perilesional zone, which was predominantly hyperechoic in 41.8% and both hypo and hyperechoic in 12.7%, could be identified in 54.5% of cases. Grade 4 tumors were more likely to have an irregular crenated margin (71.2%) with a single large area of necrosis, while Grade 3 tumors were likely to have smooth (31.3%) or non-characterizable margins (31.2%) with no or multiple areas of necrosis. IDH-negative tumors were more likely to have a single large focus of necrosis. Among the GBMs (52 cases), MIB labelling index of>15% was associated with poorly delineated, uncharacterizable margins, when compared with MIB labelling index<15% (23.5 vs. 0%), (p=0.046).

Conclusion A detailed semantic proforma was developed for brain tumors and was internally validated. A few ultrasound sematic features were identified correlating with histological features in high-grade gliomas. It will require further external validation for refinement and acceptability.

Coplanar Indirect-Navigated Intraoperative Ultrasound: Matching Un-navigated Probes With Neuronavigation During Neurosurgical Procedures. How We Do It

BACKGROUND

Intraoperative ultrasound (IOUS) is becoming more and more adopted in neurosurgery, since it has been associated to greater extent of resection (EOR) and to gross total resection (GTR) during brain tumor surgery. IOUS main limitations are spatial resolution, width and orientation of the field of view and scan quality, which are operator-dependent. Furthermore, most neurosurgeons are not confident with this technique, which needs a long learning curve in order to identify and interpret anatomic structures.

OBJECTIVE

To describe an effective procedure to take advantages of both IOUS and neuronavigation in case of lack of a navigated ultrasound system.

METHODS

We propose a reliable "indirect-navigated" technique which is based on the optical tracking of un-navigated IOUS probe by the use of a multipurpose passive tracker and a proper configuration of common neuronavigation system.

RESULTS

Navigated IOUS is not available in all neurosurgical operating rooms but ultrasound systems are common tools in many hospital facilities and neuronavigation systems are common in almost all the neurosurgical operating rooms. The proposed indirect-navigated technique shows some paramount advantages: since almost all the neurosurgical operating rooms are provided with a neuronavigation system, the only tool needed is the ultrasonography. Therefore, this procedure is largely accessible and costless, reliable, and may improve the neurosurgeon's ability in ultrasonographic anatomy.

CONCLUSION

This technique is based on the coplanar and coupled use of both un-navigated IOUS probe and standard optical neuronavigation, in order to allow the intraoperative navigation of IOUS images when a navigated ultrasound system is not available.

Ultrasound in pediatric surgery; intraoperative applications of the growing technology

Background

Ultrasonography is increasingly used in pediatric surgery. Intraoperatively, ultrasonography can be used to confirm the preoperative diagnosis, guide the surgical approach, and enhance decision-making. We aimed to report our experience with intraoperative ultrasonography in different neonatal and pediatric procedures. So, a retrospective study was designed. It included all pediatric patients who had intraoperative ultrasound between January 2018 and October 2020 in a single center.

Results

We used intraoperative ultrasonography in 208 pediatric patients for various types of surgery. The authors compared ultrasound-guided central line insertion (n = 139) to the landmark method (n = 153). The number of trials was significantly lower in the ultrasound-guided method (P < 0.001). Conversion to cut-down was significantly lower with the ultrasound-guided technique (4 (2.8%) vs. 13 (8.5%); P = 0.047) and insertion-related complications were lower with ultrasound (0 vs 13 (8.5%); P < 0.001). We used ultrasound-guided sclerotherapy for cystic hygroma in 15 patients. Nine patients had successful treatment with a single injection (60%).

Conclusion

The application of intraoperative ultrasound in pediatric patients is increasing in our institution. The technique is safe and could effectively reduce central line insertion complications and enhance cystic hygroma sclerotherapy’s success with a single injection. Ultrasonography should be an essential part of residents’ and fellows’ training in pediatric surgery.

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.

Enhanced Safety of Pedicle Subtraction Osteotomy Using Intraoperative Ultrasound

BACKGROUND

Pedicle subtraction osteotomy (PSO) can improve sagittal alignment but carries risks, including iatrogenic spinal cord and nerve root injury. Critically, during the reduction phase of the technique, medullary kinking or neural element compression can lead to neurologic deficits.

METHODS

We describe 3 cases of thoracic PSO and evaluate the feasibility, findings, and utility of intraoperative ultrasound in this setting.

RESULTS

Intraoperative ultrasound can provide a visual assessment of spinal cord morphology before and after PSO reduction and influences surgical decision making with regard to the final amount of sagittal plane correction. This modality is particularly useful for confirming ventral decompression of disc-osteophyte complex before reduction and also after reduction maneuvers when there is kinking of the thecal sac but uncertainty about the underlying status of the spinal cord. Intraoperative ultrasound is a reliable modality that fits well into the technical sequence of PSO, adds a minimal amount of operative time, and has few limitations.

CONCLUSIONS

We propose that intraoperative ultrasound is a useful supplement to standard neuromonitoring modalities for ensuring safe PSO reduction and decompression of neural elements.

Integration of Comprehensive Metrics into the PsT1 Neuroendoscopic Training System

OBJECTIVE

Metric-based surgical training can be used to quantify the level and progression of neurosurgical performance to optimize and monitor training progress. Here we applied innovative metrics to a physical neurosurgery trainer to explore whether these metrics differentiate between different levels of experience across different tasks.

METHODS

Twenty-four participants (9 experts, 15 novices) performed 4 tasks (dissection, spatial adaptation, depth adaptation, and the A-B-A task) using the PsT1 training system. Four performance metrics (collision, precision, dissected area, and time) and 6 kinematic metrics (dispersion, path length, depth perception, velocity, acceleration, and motion smoothness) were collected.

RESULTS

For all tasks, the execution time (t) of the experts was significantly lower than that of novices (P < 0.05). The experts performed significantly better in all but 2 of the other metrics, dispersion and sectional area, corresponding to the A-B-A task and dissection task, respectively, for which they showed a nonsignificant trend towards better performance (P = 0.052 and P = 0.076, respectively).

CONCLUSIONS

It is possible to differentiate between the skill levels of novices and experts according to parameters derived from the PsT1 platform, paving the way for the quantitative assessment of training progress using this system. During the current coronavirus disease 2019 pandemic, neurosurgical simulators that gather surgical performance metrics offer a solution to the educational needs of residents.

Current Limitations of Intraoperative Ultrasound in Brain Tumor Surgery

While benefits of intraoperative ultrasound (IOUS) have been frequently described, data on IOUS limitations are relatively sparse. Suboptimal ultrasound imaging of some pathologies, various types of ultrasound artifacts, challenging patient positioning during some IOUS-guided surgeries, and absence of an optimal IOUS probe depicting the entire sellar region during transsphenoidal pituitary surgery are some of the most important pitfalls. This review aims to summarize prominent limitations of current IOUS systems, and to present possibilities to reduce them by using ultrasound technology suitable for a specific procedure and by proper scanning techniques. In addition, future trends of IOUS imaging optimization are described in this article.

A Systematic Review of Educational Mobile-Applications (Apps) for Surgery Residents: Simulation and Beyond

INTRODUCTION

The number of mobile-applications (Apps) increases daily. The regulation of App content is minimal yet surgical residents use these in daily educational practice. Surgical educators must be aware of the quality, efficacy, and validity of Apps available to effectively educate residents. The aim of this review was to determine the quality, efficacy, and validity evidence for educational Apps used by surgical residents.

MATERIALS AND METHODS

We searched PubMed, Embase, and ERIC for articles published before September 1, 2019. Controlled vocabulary and natural language describing Apps/surgical residents were used. Two reviewers evaluated abstracts for inclusion.

INCLUSION CRITERIA

studies measuring the quality, efficacy, or validity of educational Apps for surgical residents. Data was extracted from full text of included articles: study design, participants, App investigated, App development, evidence for efficacy, or validity of App.

RESULTS

Initial search identified 278 articles. 64 articles were duplicates and 214 articles were screened. A further 156 were excluded with 58 full text articles assessed for eligibility. Forty-five were included in analysis. Simulation (9/45) and Feedback (15/45) Apps were the most commonly studied in surgical residents. These were the main Apps that provided validity evidence for their use in education.

CONCLUSION

Surgical education is evolving as educational technology becomes more prevalent. To be effective as surgical educators we must understand and appropriately use available tools. Of the educational Apps studied (21 Apps in 8 categories), only 3 categories reported validity evidence. Future studies should take care to measure validity and efficacy of educational Apps for surgical education to ensure quality control.

EANS Basic Brain Course (ABC): combining simulation to cadaver lab for a new concept of neurosurgical training

BACKGROUND

Neurosurgical training has traditionally been based on an apprenticeship model that requires considerable time and exposure to surgeries. Unfortunately, nowadays these requirements are hampered by several limitations (e.g., decreased caseload, worktime restrictions). Furthermore, teaching methods vary among residency programs due to cultural differences, monetary restrictions, and infrastructure conditions, with the possible consequence of jeopardizing residents' training.

METHODS

The EANS Basic Brain Course originated from a collaboration between the Besta NeuroSim Center in Milano and the Swiss Foundation for Innovation and Training in Surgery in Geneva. It was held for 5 neurosurgical residents (PGY1-3) who participated to this first pilot experience in January 2019. The main goal was to cover the very basic aspects of cranial surgery, including both technical and non-technical skills. The course was developed in modules, starting from the diagnostic paths and communication with patients (played by professional actors), then moving to practical simulation sessions, rapid theoretical lessons, and discussions based on real cases and critical ethical aspects. At the end, the candidates had cadaver lab sessions in which they practiced basic emergency procedures and craniotomies. The interaction between the participants and the faculties was created and maintained using role plays that smoothly improved the cooperation during debriefs and discussions, thus making the sessions exceedingly involving.

RESULTS

At the end of the course, every trainee was able to complete the course curriculum and all the participants expressed their appreciation for this innovative format, with a particular emphasis on the time spent learning non-technical skills, confirming that they feel this to be a fundamental aspect of a comprehensive training in neurosurgery.

CONCLUSIONS

It is possible that this combined concept of training on technical and non-technical skills, using emerging technologies along with pedagogic techniques and cadaver dissection, may become the state-of-the-art for European Neurosurgical training programs in the next future.

Dynamic assessment of venous anatomy and function in neurosurgery with real-time intraoperative multimodal ultrasound: technical note

The relevance of the cerebral venous system is often underestimated during neurosurgical procedures. Damage to this draining system can have catastrophic implications for the patient. Surgical decision-making and planning must consider each component of the venous compartment, from the medullary draining vein to the dural sinuses and extracranial veins. Intraoperative ultrasound (ioUS) permits the real-time study of venous compartments using different modalities, thus allowing complete characterization of their anatomical and functional features. The B-mode (brightness mode) offers a high-resolution anatomical representation of veins and their relationships with lesions. Doppler modalities (color, power, spectral) allow the study of blood flow and identification of vessels to distinguish their functional characteristics. Contrast-enhanced US allows one to perform real-time angiosonography showing both the functional and the anatomical aspects of vessels. In this technical report, the authors demonstrate the different applications of multimodal ioUS in neurosurgery for identifying the anatomical and functional characteristics of the venous compartment. They discuss the general principles and technical nuances of ioUS and analyze their potential implications for the study of various venous districts during neurosurgical procedures.