Endovascular Simulation Research Articles

Abstract No. 444 - Endovascular simulation with medical students: survey results from the 2016 Society of Interventional Radiology Annual Meeting

Abstract No. 444 - Endovascular simulation with medical students: survey results from the 2016 Society of Interventional Radiology Annual Meeting

Three-dimensional (3D) printed endovascular simulation models: a feasibility study

Three-dimensional (3D) printing is a manufacturing process in which an object is created by specialist printers designed to print in additive layers to create a 3D object. Whilst there are initial promising medical applications of 3D printing, a lack of evidence to support its use remains a barrier for larger scale adoption into clinical practice. Endovascular virtual reality (VR) simulation plays an important role in the safe training of future endovascular practitioners, but existing VR models have disadvantages including cost and accessibility which could be addressed with 3D printing. This study sought to evaluate the feasibility of 3D printing an anatomically accurate human aorta for the purposes of endovascular training. A 3D printed model was successfully designed and printed and used for endovascular simulation. The stages of development and practical applications are described. Feedback from 96 physicians who answered a series of questions using a 5 point Likert scale is presented. Initial data supports the value of 3D printed endovascular models although further educational validation is required.

Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method.

Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.

SS10. Advanced Vascular Surgery Surgical Skills and Simulated Assessment Program for Senior Vascular Surgery Trainees

Cognitive competence in vascular surgery is determined by oral and written examinations administered by the Vascular Surgery Board. Technical competence of vascular surgery trainees is determined solely by subjective assessment from faculty members of the trainee's institution. This program represents the first attempt to objectively evaluate the advanced vascular surgical skills of senior vascular trainees using high-fidelity simulation models by an independent faculty proctor. Nineteen senior vascular trainees were evaluated over a 3-day period. Twenty-five board-certified vascular surgeons served as assessment proctors. Assessment stations included thoracic and abdominal aortic aneurysm endograft repair, open abdominal aortic aneurysm repair, carotid endarterectomy, femoral-popliteal bypass, arteriovenous fistula creation, mismatched end-to-side anastomosis at depth, carotid, renal, iliac, and superficial femoral artery angioplasty and stenting, and use of a percutaneous closure device. Trainees were given 1 hour to complete each station. Technical performances were evaluated by a single faculty member using global rating scales, critical task and time assessment metrics, and a global rating summary. Competency was defined as achieving >80% global rating scale score, 100% achievement of all critical task metrics, or attainment of a level 4 (proficient) or level 5 (advanced) global rating summary score. Immediate feedback was provided after each performance. Six simulation stations were videotaped for future assessment metrics validation. A total of 202 skill and simulation assessments were performed. Vascular trainees were graded as being proficient for 83% (global rating scale), 75% (global rating summary), and 49% (critical task metrics) of all surgical skills and simulated performances. Similar patterns of trainee technical and procedural errors were noted to occur for each simulated procedure. The performance results identified a range of technical skills among the trainees. Faculty assessment was inconsistent with reporting errors or omissions occurring in 18%. Endovascular simulator malfunction occurred in just 4% of procedures. No malfunctions occurred in the open vascular simulators. These preliminary results indicate that it is feasible to perform objective assessment of senior vascular trainees by board-certified vascular surgery faculty using multiple objective assessment metrics. Simulation models overall exhibited good durability and consistency, and therefore appear to be useful in the assessment of advanced vascular surgical skills. Data from this initial feasibility study can be used to determine reproducible objective assessment metrics. These metrics, once validated, can than serve as a foundation for a technical competence examination in vascular surgery.

Endovascular aneurysm repair simulation can lead to decreased fluoroscopy time and accurately delineate the proximal seal zone

The use of simulators for endovascular aneurysm repair (EVAR) is not widespread. We examined whether simulation could improve procedural variables, including operative time and optimizing proximal seal. For the latter, we compared suprarenal vs infrarenal fixation endografts, right femoral vs left femoral main body access, and increasing angulation of the proximal aortic neck. Computed tomography angiography was obtained from 18 patients who underwent EVAR at a single institution. Patient cases were uploaded to the ANGIO Mentor endovascular simulator (Simbionix, Cleveland, Ohio) allowing for three-dimensional reconstruction and adapted for simulation with suprarenal fixation (Endurant II; Medtronic Inc, Minneapolis, Minn) and infrarenal fixation (C3; W. L. Gore & Associates Inc, Newark, Del) deployment systems. Three EVAR novices and three experienced surgeons performed 18 cases from each side with each device in randomized order (n= 72 simulations/participant). The cases were stratified into three groups according to the degree of infrarenal angulation: 0° to 20°, 21° to 40°, and 41° to 66°. Statistical analysis used paired t-test and one-way analysis of variance. Mean fluoroscopy time for participants decreased by 48.6% (P< .0001), and total procedure time decreased by 33.8% (P< .0001) when initial cases were compared with final cases. When stent deployment accuracy was evaluated across all cases, seal zone coverage in highly angulated aortic necks was significantly decreased. The infrarenal device resulted in mean aortic neck zone coverage of 91.9%, 89.4%, and 75.4% (P< .0001 by one-way analysis of variance), whereas the suprarenal device yielded 92.9%, 88.7%, and 71.5% (P< .0001) for the 0° to 20°, 21° to 40°, and 41° to 66° cases, respectively. Suprarenal fixation did not increase seal zone coverage. The side of femoral access for the main body did not influence proximal seal zone coverage regardless of infrarenal angulation. Simulation of EVAR leads to decreased fluoroscopy times for novice and experienced operators. Side of femoral access did not affect precision of proximal endograft landing. The angulated aortic neck leads to decreased proximal seal zone coverage regardless of infrarenal or suprarenal fixation devices.

The role of simulation in the development of endovascular surgical skills.

Endovascular trainees in the National Health Service still largely rely on the apprentice-apprenticeship model from the late 19th century. As the scope for endovascular therapy increases, due to the rapid innovation, evolution and refinement of technology, so too do patients’ therapeutic options. This climate has also opened the door for more novel training adjuncts, to address the gaps that exist in our current endovascular training curriculum. The aim of this paper is to present a succinct overview of endovascular simulation, synthesizing the trials and research behind this rapidly evolving training as well as highlighting areas where further research is required. The authors searched MEDLINE and EMBASE for relevant manuscripts on all aspects of endovascular simulation training. A comprehensive Google search was also undertaken to look for any relevant information on endovascular training courses available and any unpublished work that had been presented at relevant scientific meetings. Papers were categorized into the four models: synthetic, animal, virtual reality and human cadaver, and separate searches for evidence of skill transfer were also undertaken. Authors of novel research projects were contacted for further details of unpublished work and permission granted to report such findings in this manuscript.

An improved real-time endovascular guidewire position simulation using shortest path algorithm.

In this study, we propose a new graph-theoretical method to simulate guidewire paths inside the carotid artery. The minimum energy guidewire path can be obtained by applying the shortest path algorithm, such as Dijkstra's algorithm for graphs, based on the principle of the minimal total energy. Compared to previous results, experiments of three phantoms were validated, revealing that the first and second phantoms overlap completely between simulated and real guidewires. In addition, 95% of the third phantom overlaps completely, and the remaining 5% closely coincides. The results demonstrate that our method achieves 87 and 80% improvements for the first and third phantoms under the same conditions, respectively. Furthermore, 91% improvements were obtained for the second phantom under the condition with reduced graph construction complexity.

An endovascular simulation exercise among radiology residents: comparison of simulation performance with and without practice

PurposeThe purpose was to compare resident endovascular simulator performance with and without prior simulation. MethodsRadiology residents were guided through a practice simulation and lectured on endovascular therapy, then randomized to simulate femoral arterial intervention with or without prior iliac simulation. Simulator measurements, performance grading and resident surveys were recorded. ResultsPrior simulation of iliac intervention significantly improved resident performance. In particular, it resulted in less catheter placement without a wire (P=.01), shorter time to proper catheter positioning (P=.045) and use of oblique digital subtraction angiography (P=.035). Survey respondents valued the experience. ConclusionEndovascular simulator training improves simulation skills. Improvement of real-world performance and generalizability remain to be shown.

Basic Endovascular Skills Trainer: A surgical simulator for the training of novice practitioners of endovascular procedures.

In recent years the clinical interest for structured training in endovascular procedures has increased. Such procedures respect the physical integrity of the patient and at the same time ensure good therapeutic results. This study describes the development and testing of the B.E.S.T. (Basic Endovascular Skills Trainer) simulator. The B.E.S.T is an innovative physical endovascular simulator to learn basic skills of endovascular surgery. The simulator was tested by 25 clinicians with different levels of experience: novices, intermediates, and experts. All clinicians agree on affirming the importance of training in endovascular surgery; in particular they consider the B.E.S.T a valid simulator to learn specific basic skills of vascular surgery.

Targeting clinical outcomes: Endovascular simulation improves diagnostic coronary angiography skills.

The purpose of this study is to determine the effects of simulation-based medical education (SBME) on the skills required to perform coronary angiography in the cardiac catheterization laboratory. Cardiovascular fellows commonly learn invasive procedures on patients. Because this approach is not standardized, it can result in inconsistent skill acquisition through exclusion of concepts and skills. Also, the learning curve varies between trainees yielding variability in skill acquisition. Therefore, coronary angiography skills are an excellent target for SBME in an environment in which direct patient care is not jeopardized. From January 2013 to June 2013, 14 cardiovascular fellows entering the cardiac catheterization laboratory at a tertiary care teaching hospital were tested on an endovascular simulator to assess baseline skills. All fellows subsequently underwent didactic teaching and preceptor-lead training on the endovascular simulator. Topics included basic catheterization skills and a review of catheterization laboratory systems. Following training, all fellows underwent a post-training assessment on the endovascular simulator. Paired t tests were used to compare items on the skills checklist and simulator defined variables. Cardiovascular fellows scored significantly higher on a diagnostic coronary angiography skills checklist following SBME using an endovascular simulator. The mean pretest score was 66.6% (SD = 9.7%) compared to 86.0% (SD = 6.3%) following simulator training (P < 0.001). Additional findings include significant reduction in procedure time and use of cine-fluoroscopy at posttest. SBME significantly improved cardiovascular fellows' performance of simulated coronary angiography skills. Standardized simulation-based education is a valuable adjunct to traditional clinical education for cardiovascular fellows.

Endovascular Simulation Leads to Efficiency and Competence in Thoracic Endovascular Aortic Repair Procedures

ObjectiveEndovascular interventions such as thoracic endovascular aortic repair (TEVAR) have largely replaced invasive open procedures, and have been demonstrated to be effective in treating patients. Our study used endovascular simulation to assess the effect of TEVAR rehearsal on surgical trainees at different levels in training. DesignParticipants were oriented on an endovascular simulator and subsequently a simulated TEVAR was performed during 4 separate sessions over a 1-month period. Metrics included total procedure/fluoroscopy time and volume of contrast used. Likert scale qualitative analysis evaluated participant׳s skills involving major procedural steps. Analysis of data across cohorts included 1-way analysis of variance, Kruskal-Wallis, and paired t-tests. SettingAll data were collected at University Hospitals—Case Medical Center, Cleveland, OH. ParticipantsIn all, 12 trainees in 3 cohorts (student, surgery resident postgraduate year [PGY] 1-3, surgery resident/fellow PGY 4-7, n = 4 each) were recruited. ResultsAll trainees reduced total procedure time (mean = 537 ± 148 vs 269 ± 66s, first session vs fourth, P < 0.05, CI: 195-341) and fluoroscopy time (mean = 201 ± 74 vs 110 ± 37s, P < 0.05, CI: 51-132) with TEVAR case progression. The student cohort decreased procedure time from 551 ± 84s to 313 ± 65s (P < 0.05, CI: 189-287) whereas PGYs 1 to 3 decreased procedure time from 591 ± 149s to 264 ± 29s (P < 0.05, CI: 113-541). Use of contrast decreased over time, but the difference was not significant. Participants acquired proficiency after a few runs in most steps of the procedure. The average qualitative score for all groups combined improved significantly (P < 0.03). PGY 4 to 7 trainees had higher technical scores but this was not statistically significant. The initial gap in junior vs senior trainee performance narrowed after a few practice sessions in all aspects evaluated. ConclusionsTEVAR rehearsal on an endovascular simulator can reduce overall procedure and fluoroscopy time, independent of trainee skill level or experience, as well as improve subjective measures of technical success. Further studies are needed to compare simulator performance to outcomes in live cases.

Perspectives on endovascular training in traditional 5+2 vascular surgery fellowship training programs

This study aimed to compare expectations and experiences of fellows to those of faculty in vascular surgery fellowship programs with regard to endovascular training. Anonymous surveys were sent to fellows (n = 235) and program directors (n = 147), with 79 fellows and 65 faculty members responding. Fellows noted higher expectations of their endovascular skills prior to starting fellowship than the faculty group reported expecting. Faculty assessed fellows' pre-training endovascular skills at a significantly lower level than the fellows' self-assessment. Fellows were significantly less satisfied with the structured aspects of endovascular training than the faculty believed them to be. Only 3% of fellows vs. 32% of faculty felt that the presence of an endovascular simulator affected how residents ranked fellowship programs during the match. In conclusion, incoming fellows in vascular surgery fellowship programs have high expectations of themselves, but may overestimate their actual pre-training endovascular skills. Fellows desire more structured endovascular training, which is not recognized by faculty. Endovascular simulators are valued, but may not be a significant draw in the match process.

Abstract No. 374 - Introduction of an endovascular simulation curriculum among radiology residents

Abstract No. 374 - Introduction of an endovascular simulation curriculum among radiology residents

Does video gaming affect orthopaedic skills acquisition? A prospective cohort-study.

IntroductionPrevious studies have suggested that there is a positive correlation between the extent of video gaming and efficiency of surgical skill acquisition on laparoscopic and endovascular surgical simulators amongst trainees. However, the link between video gaming and orthopaedic trauma simulation remains unexamined, in particular dynamic hip screw (DHS) stimulation.ObjectiveTo assess effect of prior video gaming experience on virtual-reality (VR) haptic-enabled DHS simulator performance.Methods38 medical students, naïve to VR surgical simulation, were recruited and stratified relative to their video gaming exposure. Group 1 (n = 19, video-gamers) were defined as those who play more than one hour per day in the last calendar year. Group 2 (n = 19, non-gamers) were defined as those who play video games less than one hour per calendar year. Both cohorts performed five attempts on completing a VR DHS procedure and repeated the task after a week. Metrics assessed included time taken for task, simulated flouroscopy time and screw position. Median and Bonett-Price 95% confidence intervals were calculated for seven real-time objective performance metrics. Data was confirmed as non-parametric by the Kolmogorov-Smirnov test. Analysis was performed using the Mann-Whitney U test for independent data whilst the Wilcoxon signed ranked test was used for paired data. A result was deemed significant when a two-tailed p-value was less than 0.05.ResultsAll 38 subjects completed the study. The groups were not significantly different at baseline. After ten attempts, there was no difference between Group 1 and Group 2 in any of the metrics tested. These included time taken for task, simulated fluoroscopy time, number of retries, tip-apex distance, percentage cut-out and global score.ConclusionContrary to previous literature findings, there was no correlation between video gaming experience and gaining competency on a VR DHS simulator.

Developing cross-specialty endovascular simulation training.

Simulation is increasingly recognised as a valuable tool in training tomorrow's doctors. This technology has the potential to improve patient safety and address some of the challenges posed by recent changes in doctors' training, yet the uptake has been slow in the majority of institutions. In our own centre, we noted existing equipment was used infrequently. We sought to address this problem through the development of a 1-day training course in simulation (SIM) and basic interventional skills aimed at trainees from across different endovascular specialties. A 1-day course for trainees in cardiology, interventional radiology and vascular surgery was piloted. A variety of endovascular simulators were used to teach core skills common to all three specialties, under the umbrella theme of safe access, safe navigation and safe closure. Independent continuing use of SIM-based training was encouraged. Trainee and faculty member experiences of SIM training in a cross-specialty environment were explored by interview and online questionnaire. Thirty-six trainees completed the pilot training course. Feedback was almost universally positive, with all trainees agreeing that SIM was useful in achieving the course's objectives, and that they would recommend the course to a colleague. Cross-specialty training was viewed positively by trainees and trainers alike, with benefits identified in knowledge and skills sharing, as well as fostering better clinical collaboration. SIM-based training was perceived as useful in promoting patient safety, and is considered to be a desirable component of future training. We present a SIM-based model that achieves economies of scale by delivering common skill-set training for doctors from different specialties. Through our experiences piloting this course we discuss how the recognised barriers to adopting this new technology may be addressed and offer insights into how SIM may be integrated into existing training programmes.

Diagnostic angiography skill acquisition with a secondary curve catheter: phase 2 of a curriculum-based endovascular simulation program

BackgroundWe have previously reported the efficacy of a simulator-based training paradigm for residents in neurosurgery with little or no prior experience in diagnostic cerebral angiography with straightfoward arch anatomy. This...

Digital Simulation of the Delivery of Stentgrafts: Towards a Clinical Application

Objectives: Surgical training is currently done in the operating room according to the halstedian model which is questioned since the appearance of the surgical simulators. Simulators actually propose progressive courses with interventions in virtual reality and objective measurements of the learning curve. We set up a center of endovascular surgical simulation in adequacy with the recommendations of the French National Authority for Health. The purpose of the study was to establish a specific training program for each category of students. Materials and Methods: We analyzed three categories of students: experts, intermediates and beginners. Three clinical cases were selected, and each one was carried out three times. The criteria of evaluation were: duration of fluoroscopy, product of contrast injected, choice and handling of the devices, surgical tactic, training of the basic sequences. We evaluated the following criteria: satisfaction, achievement of the teaching objectives, modification of the professional behavior, evaluation of the trainers. Results: All the students showed a progressive reduction in duration of fluoroscopy, of product of contrast, quantity of material used, and procedural irregularities. The experts always carried out various surgical approaches; the intermediates initially carried out the same tactics in the first two cases and a different approach in the third case; the beginners always used the same tactics. The teacher intervened as facilitator more often for the beginners than for the experts. Conclusion: The simulator is an important teaching tool for the training of endovascular techniques. The results of the automatic analysis carried out by the software do not reflect the performance levels and a secondary analysis by the expertteacher is necessary. If the presence of the teacher during the sessions of simulation is desirable for experienced surgeons, it remains essential for the training of the residents.

An Approach to EVAR Simulation Using Patient Specific Modeling

The Simbionix Angiomentor Procedure Rehearsal Studio (PRS) offers accurate virtual anatomy for measurement, stent graft selection, and deployment of endovascular aneurysm repair (EVAR) devices. Selected Gore Excluder EVAR cases from our EVAR database were reviewed and DICOM data loaded into the Simbionix Angiomentor simulator using PRS software. Using centerline measurements created on PRS, neck diameter (D1), length from lowest renal artery to each iliac bifurcation (Ll and Lr), and common iliac artery diameter (Dl and Dr) were recorded. All measurements for device selection were made based on data recorded on the simulator. Simulated EVAR was then performed using PRS on a dual limb endovascular simulator. Changes in device selection based on intraoperative measurements and use of three-dimensional (3D) anatomic overlay made by the attending vascular surgeon performing the case were recorded. The devices actually used for successful repair were considered gold standard for comparison. At the completion of each virtual case, simulations were rated by an experienced vascular surgeon for realism, imaging quality, and final product on a 5-point scale. Ten cases with complete operative data and available computed tomography scans were chosen at random. Fifty percent of the cases (5/10) had changes in device length when using the "invivo" 3D volume filled model and angiographic measurements. Analysis of variance revealed no significant differences between the groups in any measurement-main body diameter P=0.960; main body length P=0.643; and contralateral limb length P=0.333. Review of simulation scoring showed ratings of diminished realism (average 2.3/5) due to unrealistic ease of wire passage and gate cannulation; however, simulation imaging and final product were scored favorably (3.7 and 3.4, respectively). The use of centerlines, angiographic measurements, and 3D modeling within the PRS software approaches real-life device selection and represents an opportunity for high fidelity patient-specific preoperative EVAR case rehearsal.

VESS22. 24-Month Data From the BRAVISSIMO: A Large Scale Prospective Trial on Self-Expanding and Balloon-Expandable Stents for TASC A and B and TASC C and D Aortoiliac Lesions

Objectives: We assessed the effects of thoracic endovascular aortic repair (TEVAR) rehearsal with an endovascular surgical simulator in surgical trainees at different levels in training. Methods: Twelve trainees in three cohorts (student, postgraduate year [PGY]1-3, and PGY 4-7) were oriented to using the Simbionix AngioMentor simulator over four sessions. Likert scale qualitative analysis evaluated participant proficiency. Analysis of data included one-way analysis of variance and paired t-tests. Results: All groups had reduction of total procedure time (mean 537 6 148 seconds vs 269 6 66 seconds, first session vs fourth; confidence interval [CI], 195-341 seconds; P < .05) and fluoroscopy time (201 6 74 vs 110 6 37 seconds; CI, 51-132 seconds; P < .05) with case progression. Procedure time significantly decreased in students (551 6 84 vs 313 6 65 seconds; CI 189-287 seconds; P < .05) and PGY 1-3 (591 6 149 vs 264 6 29 seconds; CI, 113541 seconds;P< .02) had a significant decrease in procedure time. Fluoroscopy times were brief overall between individuals and groups and did not change significantly with case progression. Participants acquired proficiency after a few runs in almost every step of the procedure. Endograft sizing appeared to be the most challenging task by qualitative analysis. PGY 4-7 trainees had higher technical scores, but this was not statistically significant. Conclusions: Practice on endovascular surgical simulators can reduce overall procedure and fluoroscopy time, independent of trainee skill level or experience. Endovascular simulators can be effective tools in residency training and maintenance of proficiency. Further studies are needed to compare simulator performance with outcomes in real cases.

VESS21. Endovascular Simulation Leads to Efficiency and Competence in TEVAR Procedures

VESS21. Endovascular Simulation Leads to Efficiency and Competence in TEVAR Procedures