Won Hyung A. Ryu

Conservative management of pituitary macroadenoma contacting the optic apparatus.

OBJECTIVES To describe the tumor characteristics and visual function in conservatively managed patients with non-functioning pituitary macroadenoma (NFMA) that contacted/compressed the visual pathway. DESIGN Retrospective case-series. SETTING Tertiary-care academic institution. PARTICIPANTS Six patients with diagnosis of NFMA. MAIN OUTCOME Visual function and radiological characteristics of the optic apparatus and pituitary tumor. RESULTS All patients had radiological evidence of optic apparatus compression but only one had visual field defect at the initial presentation. While two of the six patients developed visual field changes during followup (41±34.8 months), the patient with visual field defect at the time of diagnosis improved to normal vision. CONCLUSIONS Select NFMAs that contact the optic apparatus, without visual dysfunction, may be managed with close ophthalmological and radiographic monitoring, depending on tumor and imaging characteristics. This may be of particular relevance in patients considered to have a high peri-operative risk, such as advanced age or significant co-morbidities.

Utility of perfusion imaging in acute stroke treatment: a systematic review and meta-analysis

Background Variability in imaging protocols and techniques has resulted in a lack of consensus regarding the incorporation of perfusion imaging into stroke triage and treatment. The objective of our study was to evaluate the available scientific evidence regarding the utility of perfusion imaging in determining treatment eligibility in patients with acute stroke and in predicting their clinical outcome. Methods We performed a systematic review of the literature using PubMed, Web of Science, and Cochrane Library focusing on themes of medical imaging, stroke, treatment, and outcome (CRD42016037817). We included randomized controlled trials, cohort studies, and case-controlled studies published from 2011 to 2016. Two independent reviewers conducted the study appraisal, data abstraction, and quality assessments of the studies. Results Our literature search yielded 13 studies that met our inclusion criteria. In total, 994 patients were treated with the aid of perfusion imaging compared with 1819 patients treated with standard care. In the intervention group 51.1% of patients had a favorable outcome at 3 months compared with 45.6% of patients in the control group (p=0.06). Subgroup analysis of studies that used multimodal therapy (IV tissue plasminogen activator, endovascular thrombectomy) showed a significant benefit of perfusion imaging (OR 1.89, 95% CI 1.43 to 2.51, p<0.01). Conclusions Perfusion imaging may represent a complementary tool to standard radiographic assessment in enhancing patient selection for reperfusion therapy, with a subset of patients having up to 1.9 times the odds of achieving independent functional status at 3 months. This is particularly important as patients selected based on perfusion status often included individuals who did not meet the current treatment eligibility criteria.

Systematic Review of Patient-Specific Surgical Simulation: Toward Advancing Medical Education☆

OBJECTIVE Simulation-based education has been shown to be an effective tool to teach foundational technical skills in various surgical specialties. However, most of the current simulations are limited to generic scenarios and do not allow continuation of the learning curve beyond basic technical skills to prepare for more advanced expertise, such as patient-specific surgical planning. The objective of this study was to evaluate the current medical literature with respect to the utilization and educational value of patient-specific simulations for surgical training. METHODS We performed a systematic review of the literature using Pubmed, Embase, and Scopus focusing on themes of simulation, patient-specific, surgical procedure, and education. The study included randomized controlled trials, cohort studies, and case-control studies published between 2005 and 2016. Two independent reviewers (W.H.R. and N.D) conducted the study appraisal, data abstraction, and quality assessment of the studies. RESULTS The search identified 13 studies that met the inclusion criteria; 7 studies employed computer simulations and 6 studies used 3-dimensional (3D) synthetic models. A number of surgical specialties evaluated patient-specific simulation, including neurosurgery, vascular surgery, orthopedic surgery, and interventional radiology. However, most studies were small in size and primarily aimed at feasibility assessments and early validation. CONCLUSIONS Early evidence has shown feasibility and utility of patient-specific simulation for surgical education. With further development of this technology, simulation-based education may be able to support training of higher-level competencies outside the clinical settingto aid learners in their development of surgical skills.

Supplementary Educational Models in Canadian Neurosurgery Residency Programs.

BACKGROUND The proposed implementation of work hour restrictions has presented a significant challenge of maintaining the quality of resident education and ensuring adequate hands-on experience that is essential for novice surgeons. To maintain the level of resident surgical competency, revision of the apprentice model of surgical education to include supplementary educational methods, such as laboratory and virtual reality (VR) simulations, have become frequent topics of discussion. We aimed to better understand the role of supplementary educational methods in Canadian neurosurgery residency training. METHODS An online survey was sent to program directors of all 14 Canadian neurosurgical residency programs and active resident members of the Canadian Neurosurgical Society (N=85). We asked 16 questions focusing on topics of surgeon perception, current implementation and barriers to supplementary educational models. RESULTS Of the 99 surveys sent, 8 out of 14 (57%) program directors and 37 out of 85 (44%) residents completed the survey. Of the 14 neurosurgery residency programs across Canada, 7 reported utilizing laboratory-based teaching within their educational plan, while only 3 programs reported using VR simulation as a supplementary teaching method. The biggest barriers to implementing supplementary educational methods were resident availability, lack of resources, and cost. CONCLUSIONS Work-hour restrictions threaten to compromise the traditional apprentice model of surgical training. The potential value of supplementary educational methods for surgical education is evident, as reported by both program directors and residents across Canada. However, availability and utilization of laboratory and VR simulations are limited by numerous factors such as time constrains and lack of resources.

Systematic review of health economic studies in cranial neurosurgery

OBJECTIVE As the cost of health care continues to increase, there is a growing emphasis on evaluating the relative economic value of treatment options to guide resource allocation. The objective of this systematic review was to evaluate the current evidence regarding the cost-effectiveness of cranial neurosurgery procedures. METHODS The authors performed a systematic review of the literature using PubMed, EMBASE, and the Cochrane Library, focusing on themes of economic evaluation and cranial neurosurgery following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Included studies were publications of cost-effectiveness analysis or cost-utility analysis between 1995 and 2017 in which health utility outcomes in life years (LYs), quality-adjusted life years (QALYs), or disability-adjusted life years (DALYs) were used. Three independent reviewers conducted the study appraisal, data abstraction, and quality assessment, with differences resolved by consensus discussion. RESULTS In total, 3485 citations were reviewed, with 53 studies meeting the inclusion criteria. Of those, 34 studies were published in the last 5 years. The most common subspecialty focus was cerebrovascular (32%), followed by neurooncology (26%) and functional neurosurgery (24%). Twenty-eight (53%) studies, using a willingness to pay threshold of US

Assessing the role of virtual reality training in Canadian Otolaryngology–Head & Neck Residency Programs: a national survey of program directors and residents

50,000 per QALY or LY, found a specific surgical treatment to be cost-effective. In addition, there were 11 (21%) studies that found a specific surgical option to be economically dominant (both cost saving and having superior outcome), including endovascular thrombectomy for acute ischemic stroke, epilepsy surgery for drug-refractory epilepsy, and endoscopic pituitary tumor resection. CONCLUSIONS There is an increasing number of cost-effectiveness studies in cranial neurosurgery, especially within the last 5 years. Although there are numerous procedures, such as endovascular thrombectomy for acute ischemic stroke, that have been conclusively proven to be cost-effective, there remain promising interventions in current practice that have yet to meet cost-effectiveness thresholds.

ReflectiveSpineVR: an immersive spine surgery simulation with interaction history capabilities

BackgroundGiven mounting pressure of work hour restrictions, resource constraints, and variability of clinical exposure, Otolaryngology–Head & Neck Surgery (OHNS) residency training has shifted away from the apprenticeship model to embrace the Royal College of Physicians and Surgeons of Canada’s “Competence by Design” initiative. As a result, appraising both current and potential educational adjuncts has become increasingly important. In this investigation, a national needs assessment survey was performed to identify strengths, weaknesses, and future opportunities of the current training landscape.MethodsAn online survey was distributed to all thirteen Canadian OHNS post-graduate administrators for completion by program directors and residents from February to October in 2016. Prior to distribution, the survey was vetted for face validity by a group of staff Otolaryngologists and questions were modified accordingly. Quantitative analysis was performed on SPSS (IBM Corp., Chicago) with non-parametric, two-tailed Mann-Whitney U testing performed on scaled questions.ResultsOf the 68 responses, 11 of 13 (84.6%) of program directors and 57 of 168 (33.9%) residents responded to the survey. All 13 programs currently utilize cadaveric laboratory dissections. Associated challenges were ranked as specimen availability, faculty participation, insufficient space, and resident time constraints. 30.8% of programs currently utilize some form of virtual reality simulator, which 90.9% of program directors felt would be a fair and effective platform for evaluation.ConclusionA discrepancy exists between the favourable attitudes of both residents and program directors towards virtual reality simulation and its actual adoption. For successful adoption to occur, the existing barriers to unconventional training must be addressed and the tangible benefits for competency based training will need to be explored.

Design-Based Comparison of Spine Surgery Simulators: Optimizing Educational Features of Surgical Simulators

This paper contributes ReflectiveSpineVR, an immersive spine surgery simulation enriched with interaction history capabilities aimed to support effective learning and training. The provided interaction history features are based on a design study we conducted exploring what makes an effective interaction history representation in spatial tasks. Existing surgical simulation systems only provide a crude way to supporting repetitive practice where the simulation needs to be restarted every time. By working closely with medical collaborators and following an iterative process, we present our novel approach to enriching users with nonlinear interaction history capabilities and supporting repetitive practice including how such features were realized in our ReflectiveSpineVR prototype. We conclude the paper with the results of a preliminary evaluation of ReflectiveSpineVR, highlighting the positive feedback regarding our history representation approach and the interface benefits.

Rethinking temporospatiality in everyday virtual environments

BACKGROUND Simulation-based education has made its entry into surgical residency training, particularly as an adjunct to hands-on clinical experience. However, one of the ongoing challenges to wide adoption is the capacity of simulators to incorporate educational features required for effective learning. The aim of this study was to identify strengths and limitations of spine simulators to characterize design elements that are essential in enhancing resident education. METHODS We performed a mixed qualitative and quantitative cohort study with a focused survey and interviews of stakeholders in spine surgery pertaining to their experiences on 3 spine simulators. Ten participants were recruited spanning all levels of training and expertise until qualitative analysis reached saturation of themes. Participants were asked to perform lumbar pedicle screw insertion on 3 simulators. Afterward, a 10-item survey was administrated and a focused interview was conducted to explore topics pertaining to the design features of the simulators. RESULTS Overall impressions of the simulators were positive with regards to their educational benefit, but our qualitative analysis revealed differing strengths and limitations. Main design strengths of the computer-based simulators were incorporation of procedural guidance and provision of performance feedback. The synthetic model excelled in achieving more realistic haptic feedback and incorporating use of actual surgical tools. DISCUSSION Stakeholders from trainees to experts acknowledge the growing role of simulation-based education in spine surgery. However, different simulation modalities have varying design elements that augment learning in distinct ways. Characterization of these design characteristics will allow for standardization of simulation curricula in spinal surgery, optimizing educational benefit.

Designing NeuroSimVR: A Stereoscopic Virtual Reality Spine Surgery Simulator

While the design of entertainment systems and 3D games often incorporates time and space in a creative and flexible manner, space and time are often viewed in a more rigorous and limited approach when designing everyday virtual environments applications. The limited exploration of temporal and spatial aspects in the design of everyday virtual environments could limit user engagement and impact the overall experience. This paper aims to initiate a discussion about: (1) the challenges and needs associated with temporospatial design in everyday virtual reality contexts and (2) how proper utilization of space and time in the design of everyday virtual environments can enrich interaction and improve user experience. We introduce a set of temporospatial design elements that can be utilized to enrich interaction within 3D contexts, and show through illustrative examples how everyday contexts can benefit from temporospatial-inspired design.