Three-Dimensional Modeling in Training, Simulation, and Surgical Planning in Open Vascular and Endovascular Neurosurgery: A Systematic Review of the Literature

Transradial Angiography Skill Acquisition Using an Endovascular Simulation Program

BACKGROUND

Given the benefits of neuroendovascular simulation to resident education, this study aimed to assess the efficacy of simulation-based training for neuroendovascular intervention with primary and secondary catheters using a transradial approach (TRA).

METHODS

Five neurosurgical residents (PGY 1-3) from our institution enrolled in a standardized pilot training protocol. Trainees used the Mentice (Gothenburg, Vastra Gotaland, Sweden) Visit G5 simulator with a type II arch using a right TRA.

RESULTS

All participants improved their total time to complete the task from the first trial to the last trial. Residents improved the overall time required to complete the task by 111.8 ± 57 seconds (52% improvement; P = 0.012). Participants reported improved knowledge of Simmons catheter formation from 1.6 ± 0.8 to 2.8 ± 1 (P = 0.035) and improved knowledge of transradial vessel selection technique from 1.6 ± 0.9 to 2.8 ± 1.1 (P = 0.035). All residents were able to illustrate a bovine arch and types 1-3 arches post-simulation. Residents rated the simulation usefulness as 4.6 ± 0.548 (scale 1 [not useful] to 5 [essential]) with 4 of the 5 residents (80%) identifying this exercise as essential. All residents rated the hands-on component of the training exercise as the most important.

CONCLUSIONS

Residents demonstrated proficiency at Simmons catheter formation and vessel selection in a type II arch over a short time period (4 attempts and <1 hour total). Residents can use simulator-based training to increase their proficiency of vessel selection using a primary or secondary catheter for a TRA.

Simulation to become a better neurosurgeon. An international prospective controlled trial: The Passion study

Introduction

Surgical training traditionally adheres to the apprenticeship paradigm, potentially exposing trainees to an increased risk of complications stemming from their limited experience. To mitigate this risk, augmented and virtual reality have been considered, though their effectiveness is difficult to assess.

Research question

The PASSION study seeks to investigate the improvement of manual dexterity following intensive training with neurosurgical simulators and to discern how surgeons' psychometric characteristics may influence their learning process and surgical performance.

Material and methods

Seventy-two residents were randomized into the simulation group (SG) and control group (CG). The course spanned five days, commencing with assessment of technical skills in basic procedures within a wet-lab setting on day 1. Over the subsequent core days, the SG engaged in simulated procedures, while the CG carried out routine activities in an OR. On day 5, all residents' technical competencies were evaluated. Psychometric measures of all participants were subjected to analysis.

Results

The SG demonstrated superior performance (p < 0.0001) in the brain tumour removal compared to the CG. Positive learning curves were evident in the SG across the three days of simulator-based training for all tumour removal tasks (all p-values <0.05). No significant differences were noted in other tasks, and no meaningful correlations were observed between performance and any psychometric parameters.

Discussion and conclusion

A brief and intensive training regimen utilizing 3D virtual reality simulators enhances residents' microsurgical proficiency in brain tumour removal models. Simulators emerge as a viable tool to expedite the learning curve of in-training neurosurgeons.

The Sellar Region as Seen from Transcranial and Endonasal Perspectives: Exploring Bony Landmarks Through New Surface Photorealistic Three-Dimensional Model Reconstruction for Neurosurgical Anatomy Training

BACKGROUND

Virtual reality-based learning of neuroanatomy is a new feasible method to explore, visualize, and dissect interactively complex anatomic regions. We provide a new interactive photorealistic three-dimensional (3D) model of sellar region microsurgical anatomy that allows side-by-side views of exocranial and endocranial surfaces to be explored, with the aim of assisting young neurosurgery residents in learning microsurgical anatomy of this complex region.

METHODS

Four head specimens underwent an endoscopic endonasal approach extended to the anterior and posterior skull base to expose the main bony anatomic landmarks of the sellar region. The same bony structures were exposed from a transcranial perspective. By using a photogrammetry method, multiple photographs from both endocranial and exocranial perspectives, different for angulations and depth, were captured, fused, and processed through dedicated software.

RESULTS

All relevant bony structures were clearly distinguishable in the 3D model reconstruction, which provides several benefits in neuroanatomy learning: first, it replicates bony structures with high degrees of realism, accuracy, and fidelity; in addition, it provides realistic spatial perception of the depth of the visualized structures and their anatomic relationships; again, the 3D model is interactive and allows a 360° self-guided tour of the reconstructed object, so that the learner can read the bones and their anatomic relationship from all desired points of view.

CONCLUSIONS

Detailed knowledge of key surgical landmarks representing keyholes and/or anatomic structures to not violate is mandatory for safer surgery, especially for a complex region such as the skull base. Highly accurate virtual and functional neurosurgical models, such as photogrammetry, can generate a realistic appearance to further improve surgical simulators and learn neuroanatomy.

Neurosurgical simulation models developed in Latin America and the Caribbean: a scoping review

Simulation training is an educational tool that provides technical and cognitive proficiency in a risk-free environment. Several models have recently been presented in Latin America and the Caribbean (LAC). However, many of them were presented in non-indexed literature and not included in international reviews. This scoping review aims to describe the simulation models developed in LAC for neurosurgery training. Specifically, it focuses on assessing the models developed in LAC, the simulated neurosurgical procedures, the model's manufacturing costs, and the translational outcomes. Simulation models developed in LAC were considered, with no language or time restriction. Cadaveric, ex vivo, animal, synthetic, and virtual/augmented reality models were included for cranial and spinal procedures. We conducted a review according to the PRISMA-ScR, including international and regional reports from indexed and non-indexed literature. Two independent reviewers screened articles. Conflicts were resolved by a third reviewer using Covidence software. We collected data regarding the country of origin, recreated procedure, type of model, model validity, and manufacturing costs. Upon screening 917 studies, 69 models were developed in LAC. Most of them were developed in Brazil (49.28%). The most common procedures were related to general neurosurgery (20.29%), spine (17.39%), and ventricular neuroendoscopy and cerebrovascular (15.94% both). Synthetic models were the most frequent ones (38.98%). The manufacturing cost ranged from 4.00 to 2005.00 US Dollars. To our knowledge, this is the first scoping review about simulation models in LAC, setting the basis for future research studies. It depicts an increasing number of simulation models in the region, allowing a wide range of neurosurgical training in a resource-limited setting.

3D-printed Titanium Prosthetic Reconstruction of Unilateral Bone Deficiency After Surgical Resection of Tumor Lesions in the Upper Cervical Spine: Clinical Outcomes of Three Consecutive Cases and Narrative Review

MAIN POINTS

Operational excision of tumor lesions in the upper cervical spine remains a tremendous challenge to surgeons due to the local complex anatomic relationships. Meanwhile, no commercially available device has been specially designed to address bone deficiency after surgical resection. Here, we described the reconstruction of unilateral bone deficiency after surgical resection of a giant cell tumor of the tendon sheath originating from the lateral atlantoaxial joint with the employment of a 3D printing technique and reviewed the relevant literature. In our study, 3 patients with giant cell tumor of the tendon sheath in the upper cervical spine achieved complete tumor removal, and received unilateral bone reconstruction with one-armed 3D-printed titanium prosthesis. During the follow-up, these patients remained neurologically intact and got back to a normal life without wearing the braces. Images demonstrated the satisfactory placement of 3D-printed prosthesis with no failure of fixation and no subsidence. In addition, 6 articles describing the employment of 3D-printed prostheses or models for tumor surgery in the upper cervical spine were reviewed, and satisfactory clinical outcomes were reported in these studies. Hence, 3D-printed titanium prosthetic reconstruction of bone deficiency in the upper cervical spine was a safe and effective technique.

LEVEL OF EVIDENCE

Level IV.

Three-Dimensional Printing in Neurosurgery: A Review of Current Indications and Applications and a Basic Methodology for Creating a Three-Dimensional Printed Model for the Neurosurgical Practice

Introduction Three-dimensional (3D) printing is an affordable aid that is useful in neurosurgery. It allows for better visualization and tactile appreciation of the individual anatomy and regions of interest and therefore potentially lowers the risk of complications. There are various applications of this technology in the field of neurosurgery. Materials and methods In this paper, we present a basic methodology for the creation of a 3D printed model using only open-source software for medical image editing, model generation, pre-printing preparation, and analysis of the literature concerning the practical use of this methodology. Results The literature review on the current applications of 3D printed models in neurosurgery shows that they are mostly used for preoperative planning, surgical training, and simulation, closely followed by their use in patient-specific implants and instrumentation and medical education. Materialise^TM Mimics is the most frequently used commercial software for a 3D modeling for preoperative planning and surgical simulation, while the most popular open-source software for the same applications is 3D Slicer. In this paper, we present the algorithm that we employ for 3D printing using Horos^TM, Blender, and Cura software packages which are all free and open-source. Conclusion Three-dimensional printing is becoming widely available and of significance to neurosurgical practice. Currently, there are various applications of this technology that are less demanding in terms of technical knowledge and required fluency in medical imaging software. These predispositions open the field for further research on the possible use of 3D printing in neurosurgery.

Effect of the Segmentation Threshold on Computed Tomography-Based Reconstruction of Skull Bones with Reference Optical Three-Dimensional Scanning

BACKGROUND

A variety of applications related to neurosurgical procedures, education, and training require accurate reconstruction of the involved structures from the medical images such as computed tomography (CT). This study evaluates the quality of CT-based reconstruction of dry skull bones for advanced neurosurgical applications. The accuracy and precision of these models were examined with reference optical scanning.

METHODS

Three consecutive CT and optical scans of different skull bones were acquired and used to develop three-dimensional models. The accuracy of three-dimensional models was examined by manual inspection of the defined anatomical landmarks of the skull. Reproducibility was examined by deviation analysis of the models developed from repeated CT and optical scans.

RESULTS

Precision was excellent in both the techniques with less than 0.1 mm deviation error. On the interscan evaluation of the CT versus optical scan model, deviations of more than 0.1 mm were observed in 16 out of 21 instances. CT reconstruction using standard segmentation algorithms results in missing bone portions while using the default bone segmentation threshold. The segmentation threshold was varied to construct missing bone regions, and its effect on the iso-surface generation was evaluated. The threshold variation led to increased mean deviations of surfaces up to 0.6 mm.

CONCLUSIONS

The study reveals that bone structure, complexity, and segmentation threshold lead to CT reconstruction variability. The trade-off between the desirable model and accepted mean deviation should be considered as per traits of the desired application.

A time-dependent offset field approach to simulating realistic interactions between beating hearts and surgical devices in virtual interventional radiology

Endovascular interventional radiology (IR) is a minimally invasive procedure for the treatment of vascular diseases. This procedure requires physicians to be highly skilled at manipulating interventional devices under the guidance of two-dimensional X-ray imaging. By offering a non-error-sensitive and radiation-free environment, a virtual reality-based simulator provides a promising alternative for surgical skills training and surgery planning. Building a realistic and interactive simulator is a challenging task. To achieve better realism, this paper proposes a novel method of simulating the heartbeat for both standard and patient-specific anatomical data. A time-dependent offset field approach is proposed to efficiently and stably simulate the interactive behavior between the dynamic heart mesh and surgical devices. For medical imaging simulation, we propose a GPU-based linear depth subtraction method to approximate fluoroscopic images based on the attenuation of the X-ray. On this basis, a topology-based flow map method is proposed to simulate the propagation of the contrast medium in angiography. Experimental results show that the proposed algorithm can simulate heartbeat stably for meshes with varying geometrical shapes and complexities. In efficiency, the dynamic heart mesh can interact with surgical devices stably at 60 frames/s. Under the simulated fluoroscopic imaging effect, the injected contrast medium can realistically visualize both dynamic and static vessels. In a face validity by medical students and clinicians, the category of effectiveness score 8.35 out of 10 on average, demonstrating that our simulator is useful in surgical skills training and surgery planning.

Needle Penetration Simulation: Influence of Penetration Angle and Sample Stress on the Mechanical Behaviors of Polymers Applying a Cast Silicone and a 3D-Printed Resin

For surgical catheterization training applications, realistic and effective materials are desired. In this study, the relevance of a needle puncture angle and a simulated wall stress on different elastic materials were determined in a previously developed experimental setup. Both settings were considered individually in two new setups. In addition, a control setup with neither angle nor prestress was designed. During the process of puncturing the samples of two materials (Replisil 9N and Formlabs Elastic 50A), force−displacement values were collected, and three predefined parameters evaluated. The differences between the angled/stressed groups and the control group were analyzed. The additively processed material required a significantly higher force to puncture than the conventional one (p < 0.001). Moreover, a needle angulation of 45° required more force than puncturing orthogonally. Prestressing the samples did not clearly influence the resulting force. An evaluation of relative parameters showed that the investigated materials behaved differently but not linearly differently under the influence of needle angle and prestress. Therefore, it is essential to evaluate the properties and suitability of materials for surgical training models in appropriate experimental setups considering multiple parameters.

Development of 3-dimensional printed simulation surgical training models for endoscopic endonasal and transorbital surgery

Background

Endoscopic skull base surgery (ESBS) is complex, requiring methodical and unremitting surgical training. Herein, we describe the development and evaluation of a novel three-dimensional (3D) printed simulation model for ESBS. We further validate the efficacy of this model as educational support in neurosurgical training.

Methods

A patient-specific 3D printed simulation model using living human imaging data was established and evaluated in a task-based hands-on dissection program. Endoscopic endonasal and transorbital procedures were simulated on the model by neurosurgeons and otorhinolaryngology surgeons of varying experience. All procedures were recorded using a high-definition camera coupled with digital video recorder system. The participants were asked to complete a post-procedure questionnaire to validate the efficacy of the model.

Results

Fourteen experts and 22 trainees participated in simulations, and the 32 participants completed the post-procedure survey. The anatomical realism was scored as 4.0/5.0. The participants rated the model as helpful in hand-eye coordination training (4.7/5.0) and improving surgical skills (4.6/5.0) for ESBS. All participants believed that the model was useful as educational support for trainees (4.7 [ ± 0.5]). However, the color (3.6/5.0) and soft tissue feedback parameters (2.8/5) scored low.

Conclusion

This study shows that high-resolution 3D printed skull base models for ESBS can be generated with high anatomical accuracy and acceptable haptic feedback. The simulation program of ESBS using this model may be supplemental or provide an alternative training platform to cadaveric dissection.