Mixed reality in interventional radiology: a focus on first clinical use of XR90 augmented reality-based visualization and navigation platform

INTRODUCTION

Augmented reality (AR) and virtual reality (VR) are emerging tools in interventional radiology (IR), enhancing IR education, preprocedural planning, and intraprocedural guidance.

AREAS COVERED

This review identifies current applications of AR/VR in IR, with a focus on studies that assess the clinical impact of AR/VR. We outline the relevant technology and assess current limitations and future directions in this space. We found that the use of AR in IR lags other surgical fields, and the majority of the data exists in case series or small-scale studies. Educational use of AR/VR improves learning anatomy, procedure steps, and procedural learning curves. Preprocedural use of AR/VR decreases procedure times, especially in complex procedures. Intraprocedural AR for live tracking is accurate within 5 mm live patients and has up to 0.75 mm in phantoms, offering decreased procedure time and radiation exposure. Challenges include cost, ergonomics, rapid segmentation, and organ motion.

EXPERT OPINION

The use of AR/VR in interventional radiology may lead to safer and more efficient procedures. However, more data from larger studies is needed to better understand where AR/VR is confers the most benefit in interventional radiology clinical practice.

Application of virtual reality in neurosurgery: Patient missing. A systematic review

Virtual reality (VR) technology had its earliest developments in the 1970s in the U.S. Air Force and has since evolved into a budding area of scientific research with many practical medical purposes. VR shows a high potential to benefit to learners and trainees and improve surgery through enhanced preoperative planning and efficiency in the operating room. Neurosurgery is a field of medicine in which VR has been accepted early on as a useful and promising tool for neuro-navigation planning. Through recent technological developments, VR further increased its level of immersion, accessibility and intuitive use for surgeons and students and now reveals a therapeutic potential for patients. In this paper, we systematically reviewed the neurosurgery literature regarding the use of VR as an assistance for surgery or a tool centered on patients' care. A literature search conducted according to PRISMA guidelines resulted in the screening of 125 abstracts and final inclusion of 100 original publications reviewed. The review shows that neurosurgeons are now relatively familiar with VR technologies (N = 95 articles) for their training and practice. VR technologies are useful for education, pain management and rehabilitation in neurosurgical patients. Nevertheless, the current patient-oriented use of VR remains limited (N = 5 articles). Successful surgery does not only depend on the surgeon's skills and preparation, but also on patients' education, comfort, empowerment and care. Therefore further clinical research is needed to promote the direct use of VR technologies by patients in neurosurgery.

Virtual Reality in Neurosurgery: "Can You See It?"-A Review of the Current Applications and Future Potential

Virtual reality (VR) technology had its early development in the 1960s in the U.S. Air Force and has since evolved into a budding area of scientific research with many practical medical purposes. From medical education to resident training to the operating room, VR has provided tangible benefits to learners and trainees and has also improved surgery through enhanced preoperative planning and efficiency in the operating room. Neurosurgery is a particularly complex field of medicine, in which VR has blossomed into a tool with great usefulness and promise. In spinal surgery, VR simulation has allowed for the practice of innovative minimally invasive procedures. In cranial surgery, VR has excelled in helping neurosurgeons design unique patient-specific approaches to particularly challenging tumor excisions. In neurovascular surgery, VR has helped trainees practice and perfect procedures requiring high levels of dexterity to minimize intraoperative complications and patient radiation exposure. In peripheral nerve surgery, VR has allowed surgeons to gain increased practice and comfort with complex microsurgeries such as nerve decompression. Overall, VR continues to increase its potential in neurosurgery and is poised to benefit patients in a multitude of ways. Although cost-prohibiting, legal, and ethical challenges surrounding this technology must be considered, future research and more direct quantitative outcome comparisons between standard and VR-supplemented procedures would help provide more direction regarding the feasibility of widespread adoption of VR technology in neurosurgery.

Operators believe patient-specific rehearsal improve individual and team performance

INTRODUCTION

Rehearsing endovascular aortic aneurysm repair on patient-specific data is recent within virtual reality simulation and opens up new possibilities for operators to prepare for complex procedures. This study evaluated the feasibility of patient-specific rehearsal (PsR) and assessed operators' appraisal of the VIST-LAB simulator from Mentice.

MATERIAL AND METHODS

CT-data was segmented and uploaded to the simulator, and simulated for 30 elective EVAR patients. Operators were asked how they perceived the PsR on a Likert scale after the PsR (once) and after the following procedure (each time).

RESULTS

Patients were simulated and operated by 14 operators, always in pairs of one vascular surgeon and one interventional radiologist. The operators estimated that PsR improved individual and team performance (median 4), and recommended the use of PsR in general (median 4) and for difficult cases (median 5). The simulator realism got moderate scores (median 2-3). Inexperienced operators seemed to appreciate the PsR the most.

CONCLUSIONS

PsR was feasible and was evaluated by operators to improve individual and team performance. Inexperienced users were more positive towards PsR than experienced users. PsR realism and the ease of importing patient-specific data can still be improved, and further studies to quantify and precisely identify benefits are needed.

Influence of patient-specific rehearsal on operative metrics and technical success for endovascular aneurysm repair

INTRODUCTION

Patient-specific rehearsal (PsR) is a recent technology within virtual reality (VR) simulation that lets the operators train on patient-specific data in a simulated environment prior to the procedure. Endovascular aneurysm repair (EVAR) is a complex procedure where operative metrics and technical success might improve after PsR.

MATERIAL AND METHODS

We compared technical success and operative metrics (endovascular procedure time, contralateral gate cannulation time, fluoroscopy time, total radiation dose, number of angiograms and contrast medium use) between 30 patients, where the operators performed PsR (the PsR group), and 30 patients without PsR (the control group).

RESULTS

The endovascular procedure time was significantly shorter in the PsR group than in the control group (median 44 versus 55 min, p = .017). The other operative metrics were similar. Technical success rates were higher in the PsR group, 96.7% primary and assisted primary outcome versus 90.0% in the control group. The differences were not significant (p = .076).

CONCLUSIONS

PsR before EVAR reduced endovascular procedure time, and our results indicate that it might improve technical success, but further studies are needed to confirm those results.

High-Fidelity Endovascular Simulation

With the ongoing changes in graduate medical education, emphasis has been placed on simulation models to increase clinical exposure and optimize learning. In specific, high-fidelity simulation presents as a potential option for procedural-skill development in interventional radiology. With improved haptic, visual, and tactile dynamics, high-fidelity endovascular simulators have gained increasing support from trainees and certified interventionalists alike. The 2 most common high-fidelity endovascular simulators utilized today are the Procedicus VIST and ANGIO Mentor, which contain notable differences in technical features, case availability, and cost. From the perspective of a trainee, high-fidelity simulation allows for the ability to perform a greater volume of cases. Additionally, without the risk of potential harm to the patient, trainees can focus on repetition and improved performance in a stress-free environment. When errors are made, high-fidelity simulator metrics will generate instantaneous feedback and error notification, erasing ambiguity and thus facilitating learning. Furthermore, in an environment devoid of time and cost stressors, the supervising physician is afforded the opportunity to properly mentor and instruct the trainee throughout the case. For the experienced interventionalists, high-fidelity simulation allows for a decreased learning curve for new procedures or techniques, as well as the opportunity for procedure rehearsal for unusual or high-risk cases. Despite the limitations created by cost, high-fidelity endovascular simulation should continue to be increasingly utilized in the development of the interventional radiology curriculum.

A Role for Virtual Reality in Planning Endovascular Procedures

Current imaging technologies are capable of acquiring volumetric data, but they are limited by the flat 2-dimensional representation of complex 3-dimensional data. This pictorial report illustrates the potential role of interactive virtual reality (VR) that enables physicians to visualize and interact with image data as if they were real physical objects. Increasing availability of tools that make the VR environment a possibility could potentially be valuable in the interventional radiology suite.

Characterization of Vessel Deformations During EVAR: A Preliminary Retrospective Analysis to Improve Fidelity of Endovascular Simulators

OBJECTIVE

During endovascular aneurysm repair (EVAR), vessel deformations occur due to the insertion of tools and deployment of stent grafts in the arteries. We present a method for the characterization of vessel deformations during EVAR, and its application on patient datasets for a preliminary retrospective analysis that may be used to improve fidelity of endovascular simulators.

DESIGN

The method provides the extraction of vessel profiles from intraoperative fluoroscopic images and the calculation of a tortuosity index in the 2D fluoroscopy view (τ_2D) used to quantify the vessel deformations (δ%) during EVAR caused by the stiff guidewire insertion (δ%_Stiff) and the stent graft deployment (δ%_Graft), when compared with the undeformed vessel configuration (no device inserted). We applied the method to analyze retrospectively 7 EVAR patient datasets, including vasculature anatomies with different grades of vessel tortuosity or calcification: 2 patients (Pts) with absent tortuosity and mild calcification, 2 with mild tortuosity and mild calcification, 2 with severe tortuosity and mild calcification, and 1 with severe tortuosity and severe calcification. The analysis was focused on deformations of the left common iliac artery (LCIA), which is one of the arterial segments most affected by deformations.

RESULTS

In patients with mild LCIA calcification, the vessel straightening effect due to the stiff guidewire insertion increases as the severity of LCIA tortuosity increases (δ%_Stiff = 0 ± 2%, -19 ± 2%, -45 ± 2% for absent, mild, and severe tortuosity, respectively). In patients with mild/severe LCIA tortuosity, the artery with the deployed graft seems to retain part of the straightening effect caused by the stiff guidewire (δ%_Graft = -9 ± 3%, -31 ± 2%, for mild and severe tortuosity, respectively). In case of severe LCIA calcification, the stiff guidewire causes only a slight straightening effect (δ%_Stiff = -12%) despite the severe vessel tortuosity.

CONCLUSION

The method was effective in characterizing real vessel deformations during EVAR. Results gave evidence of a relationship between the obtained deformations and the anatomical vessel conformation. These results may be useful to drive predictive models of vessel deformations during EVAR to be implemented in endovascular patient-specific simulators for improving their fidelity.

The Role of Simulation in Boosting the Learning Curve in EVAR Procedures

OBJECTIVE

Simulation may be a useful tool for training in endovascular procedures. The aim of this study was to evaluate the effect of endovascular repair of abdominal aortic aneurysms (EVAR) simulation in boosting trainees' learning curve.

DESIGN

Ten vascular surgery residents were recruited and divided in 2 groups (Trainee Group and Control group). At a first session (t₀), each resident performed 2 simulated EVAR procedures using an endovascular simulator. After 2 weeks, each participant simulated other 2 EVAR procedures in a final session (t₁). In the period between t₀ and t₁, each resident in the Trainee Group performed 6 simulated EVAR procedures, whereas the Control Group did not perform any other simulation. Both quantitative and qualitative performance evaluations were performed at t₀ and t₁. Quantitative evaluation from simulator metrics included total procedural time (T_P), total fluoroscopy time (T_F), time for contralateral gate cannulation (T_G), and contrast medium volume (CM) injected. Qualitative evaluation was based on a Likert scale used to calculate a total performance score referred to skills involving major EVAR procedural steps.

RESULTS

All residents in the Trainee Group significantly reduced T_P (48 ± 12 vs 32 ± 8 minutes, t₀ vs t₁, p < 0.05), T_F (18 ± 7 vs 11 ± 6 minutes, p < 0.05), and CM used over time (121 ± 37 vs 85 ± 26ml, p < 0.05), but not T_G (5 ± 5 vs 3 ± 4 minutes, p = 0.284). In the Control Group metrics did not change significantly in any field (T_P = 55 ± 11 vs 46 ± 10 minutes; T_F = 25 ± 9 vs 21 ± 4 minutes; CM = 132 ± 51 vs 102 ± 42ml; T_G = 6 ± 4 vs 8 ± 5 minutes, all p > 0.05). The average Trainee Group qualitative total performance score improved significantly (p < 0.05) after rehearsal sessions when compared with the Control Group.

CONCLUSION

Simulation is an effective method to improve competence of vascular surgery residents with EVAR procedures.

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.

Evidence for Endovascular Simulation Training: A Systematic Review

BACKGROUND

Simulation training in endovascular surgery provides opportunities for trainees to practice and learn from non-patient based experience. Several types of endovascular simulators are available commercially. Previous studies on endovascular simulation training can be categorized into trials in which only a simulator was used when measuring performance metrics or "trials within simulation"; patient specific procedure rehearsals; and randomized, controlled trials (RCTs) or translational studies.

OBJECTIVES

To examine whether endovascular simulation training can improve surgeon techniques and patient outcomes in real clinical settings.

METHODS

A literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All searches were done via PubMed and Embase. Review articles, and papers that were not related to endovascular surgery and not within the scope of interest were excluded. References of review articles were further screened according to the exclusion criteria.

RESULTS

In total, 909 records were identified and 290 duplicates were removed. Thirty-one were included in the qualitative analysis. Twenty-three were trials within simulation and most of them found statistically significant improvements in procedure time, fluoroscopy time, and contrast volume. Five were patient specific procedure rehearsals and showed that simulation significantly affected the fluoroscopy angle and improved performance metrics. Three were RCTs and revealed mainly positive results on a Global Rating Scale and procedure specific rating scale.

CONCLUSIONS

Contemporary evidence shows that performance metrics within endovascular simulations improve with simulation training. Successful translation to in vivo situations is observed in patient specific procedure rehearsals and RCTs on real procedures. However, there is no level I evidence to show that predictive validity of simulation can definitively improve patient outcomes. Current literature supports the idea that there is a beneficial role of simulation in endovascular training. Future studies are needed to confirm the efficacy of simulation in endovascular surgical training and to see if simulation is superior to traditional training in the operating theatre.

A study of the effect of dyad practice versus that of individual practice on simulation-based complex skills learning and of students' perceptions of how and why dyad practice contributes to learning

PURPOSE

The aims of this study were (1) to explore the effectiveness of dyad practice compared with individual practice on a simulator for learning a complex clinical skill and (2) to explore medical students' perceptions of how and why dyad practice on a simulator contributes to learning a complex skill.

METHOD

In 2011, the authors randomly assigned 84 medical students to either the dyad or the individual practice group to learn coronary angiography skills using instruction videos and a simulator. Two weeks later, participants each performed two video-recorded coronary angiographies on the simulator. Two raters used a rating scale to assess the participants' video-recorded performance. The authors then interviewed the participants in the dyad practice group.

RESULTS

Seventy-two (86%) participants completed the study. The authors found no significant difference between the performance scores of the two groups (mean±standard deviation, 68%±13% for individual versus 63%±16% for dyad practice; P=.18). Dyad practice participants noted that several key factors contributed to their learning: being equal-level novices, the quality of the cooperation between partners, observational learning and overt communication, social aspects and motivation, and meta-cognition.

CONCLUSIONS

Dyad practice is more efficient and thus more cost-effective than individual practice and can be used for costly virtual reality simulator training. However, dyad practice may not apply to clinical training involving real patients because learning from errors and overt communication, both keys to dyad practice, do not transfer to clinical practice.

Carotid Artery Stenting - Strategies to Improve Procedural Performance and Reduce the Learning Curve

Carotid artery stenting (CAS) remains an appealing intervention to reduce the stroke risk because of its minimal invasive nature. Nevertheless, landmark randomised controlled trials have not been able to resolve the controversies surrounding this complex procedure as the peri-operative stroke risk in a non-selected patient population still seems to be higher after CAS in comparison to carotid endarterectomy. What is more, these trials have highlighted that patient outcome after CAS is influenced by patient- and operator-dependant factors. The CAS procedure exhibits a definitive learning curve resulting in higher complication rates if the procedure is performed by inexperienced interventionists or in low-volume centres. This article will outline strategies to improve the performance of physicians carrying out the CAS procedure by means of proficiency-based training, credentialing, virtual reality rehearsal and optimal patient selection.

Role of patient-specific virtual reality rehearsal in carotid artery stenting

Background

Recent advances in simulation science permit patient-specific rehearsal of endovascular stenting procedures. This study aimed to evaluate how effectively real interventions are replicated by patient-specific rehearsal technology, and to assess its value as a preparatory tool for the interventionalist and the operating team.

Methods

All patients deemed candidates for carotid artery stenting procedures with suitable computed tomography images were enrolled. Each team member rehearsed the virtual procedure in the laboratory, simulated operating theatre or angiography suite environment immediately before treating the real patient. Dexterity and qualitative metrics were recorded. Subjective questionnaires used a Likert scale from 1 (poor) to 5 (excellent).

Results

Of 18 patients, three were excluded. In 11 of 15 and 13 of 15 patients respectively endovascular tool use and fluoroscopy angles were identical during rehearsal and the real procedure. In a third of patients, the simulator did not adequately predict difficulties in cannulating the stenotic internal or common carotid arteries. The procedure realism, value in evaluating the case, increase in efficiency in tool use, and potential to increase communication, confidence and team performance were all rated highly (4 of 5).

Conclusion

Patient-specific rehearsal was rated highly for both face and content validity. Access strategy, endovascular material use and angiographic imaging were all replicated effectively, although certain biomechanical vessel properties seemed to be replicated to a lesser degree. Patient-specific rehearsal constitutes a unique tool that may help tailor endovascular material choice, and optimize the preoperative preparation of the interventionalist and team.

Training in surgical oncology - the role of VR simulation

There have been dramatic changes in surgical training over the past two decades which have resulted in a number of concerns for the development of future surgeons. Changes in the structure of cancer services, working hour restrictions and a commitment to patient safety has led to a reduction in training opportunities that are available to the surgeon in training. Simulation and in particular virtual reality (VR) simulation has been heralded as an effective adjunct to surgical training. Advances in VR simulation has allowed trainees to practice realistic full length procedures in a safe and controlled environment, where mistakes are permitted and can be used as learning points. There is considerable evidence to demonstrate that the VR simulation can be used to enhance technical skills and improve operating room performance. Future work should focus on the cost effectiveness and predictive validity of VR simulation, which in turn would increase the uptake of simulation and enhance surgical training.