Surgeon Upper Extremity Kinematics During Error and Error-Free Retropubic Trocar Passage

INTRODUCTION AND HYPOTHESIS

Surgeon kinematics play a significant role in the prevention of patient injury. We hypothesized that elbow extension and ulnar wrist deviation are associated with bladder injury during simulated midurethral sling (MUS) procedures.

METHODS

We used motion capture technology to measure surgeons' flexion/extension, abduction/adduction, and internal/external rotation angular time series for shoulder, elbow, and wrist joints. Starting and ending angles, minimum and maximum angles, and range of motion (ROM) were extracted from each time series. We created anatomical multibody models and applied linear mixed modeling to compare kinematics between trials with versus without bladder penetration and attending versus resident surgeons. A total of 32 trials would provide 90% power to detect a difference.

RESULTS

Out of 85 passes, 62 were posterior to the suprapubic bone and 20 penetrated the bladder. Trials with versus without bladder penetration were associated with more initial wrist dorsiflexion (-27.32 vs -9.03°, p = 0.01), less final elbow flexion (39.49 vs 60.81, p = 0.03), and greater ROM in both the wrist (27.48 vs 14.01, p = 0.02), and elbow (20.45 vs 12.87, p = 0.04). Wrist deviation and arm pronation were not associated with bladder penetration. Compared with attendings, residents had more ROM in elbow flexion (14.61 vs 8.35°, p < 0.01), but less ROM in wrist dorsiflexion (13.31 vs 20.33, p = 0.02) and arm pronation (4.75 vs 38.46, p < 0.01).

CONCLUSIONS

Bladder penetration during MUS is associated with wrist dorsiflexion and elbow flexion but not internal wrist deviation and arm supination. Attending surgeons exerted control with the wrist and forearm, surgical trainees with the elbow. Our findings have direct implications for MUS teaching.

Anatomic Review in 3D Augmented Reality Alters Craniotomy Planning Among Residents

OBJECTIVE

Objectively examine the effect of 3D-Augmented Reality anatomic review on craniotomy planning among neurosurgical residents as it pertains to craniotomy size, skull positioning, and knowledge of significant anatomic relationships.

METHODS

Postgraduate year 1-7 neurosurgery residents were instructed to review standard 2D radiographs, pin a skull, and tailor a craniotomy for 6 different lesions and case vignettes. Participants then reviewed the lesion in a 3D-augmented reality (AR) environment, followed by repeating the craniotomy station for a variety of lesion types and locations (superficial, subcortical, deep, skull base). Quiz with case-specific anatomic and surgical questions followed by an exit survey for qualitative impressions.

RESULTS

Eleven of thirteen eligible residents participated. Skull position significantly changed in 5 out of 6 cases after 3D-AR view (P < 0.05, 20° angular adjustment). No significant change in incision length or craniotomy size. Subgroup analysis of junior versus senior residents revealed that craniotomy size was significantly altered in 2 out of 6 cases. Qualitative testimonials (Likert scale 5 = strongly agree) reported a change in craniotomy approach after 3D-review (3.5), improved appreciation of anatomy (4.2), increased confidence in surgical approach (4.33 junior residents, 3.5 senior residents), smaller incision (3.5 junior residents, 1.75 senior residents), better appreciation of white matter tracts (4.6).

CONCLUSIONS

The augmented reality platform offers a medium to examine surgical planning skills. Residents uniformly appreciated 3D-AR as a valuable tool for improving appreciation of critical anatomic structures and their relationship to lesional pathology. 3D-AR review significantly altered skull positioning for various lesions and craniotomy approaches, particularly among junior residents.

Minimal data requirement for realistic endoscopic image generation with Stable Diffusion

PURPOSE

Computer-assisted surgical systems provide support information to the surgeon, which can improve the execution and overall outcome of the procedure. These systems are based on deep learning models that are trained on complex and challenging-to-annotate data. Generating synthetic data can overcome these limitations, but it is necessary to reduce the domain gap between real and synthetic data.

METHODS

We propose a method for image-to-image translation based on a Stable Diffusion model, which generates realistic images starting from synthetic data. Compared to previous works, the proposed method is better suited for clinical application as it requires a much smaller amount of input data and allows finer control over the generation of details by introducing different variants of supporting control networks.

RESULTS

The proposed method is applied in the context of laparoscopic cholecystectomy, using synthetic and real data from public datasets. It achieves a mean Intersection over Union of 69.76%, significantly improving the baseline results (69.76 vs. 42.21%).

CONCLUSIONS

The proposed method for translating synthetic images into images with realistic characteristics will enable the training of deep learning methods that can generalize optimally to real-world contexts, thereby improving computer-assisted intervention guidance systems.

Merits of simulation-based education: A systematic review and meta-analysis

BACKGROUND

The drive to improve surgical proficiency through advanced simulation-based training has gained momentum. This meta-analysis systematically evaluated evidence regarding the impact of plastic surgery-related simulation on the performance of residents.

METHODS

A systematic search of PubMed, Web of Science, and Cochrane Library and review of articles was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis protocol. An inverse-variance random-effects model was used to combine study estimates to account for between-study variability. Objective structured assessment of technical skills (OSATS) scores and subjective confidence scores were used to assess the impact of the simulation with positive changes from the baseline indicating better outcomes.

RESULTS

Eighteen studies pooling 367 trainees who participated in various simulations were included. Completion of simulation training was associated with significant improvement in subjective confidence scores with a mean increase of 1.44 units (95% CI: 0.93 to 1.94, P < 0.001), and in OSATS scores, with a mean increase of 1.24 units (95% CI: 0.87 to 1.62, P < 0.001), both on a 1-5 scale. Participants reported high satisfaction scores (mean = 4.76 units, 95% CI = 4.61 to 4.91, P = 0.006), also on a 1-5 scale.

CONCLUSIONS

Participation in surgical simulation markedly improved objective and subjective scoring metrics for surgical trainees. Several simulation devices are available for honing surgical skills, with the potential for advancements. The evidence demonstrates the effectiveness of simulations; thus, incorporating simulation into training curricula should be a priority in the field of plastic surgery.

Virtual Reality-Enabled Resident Education of Lateral-Access Spine Surgery

OBJECTIVE

Lateral-access spine surgery has many benefits, but adoption has been limited by a steep learning curve. Virtual reality (VR) is gaining popularity and lends itself as a useful tool in enhancing neurosurgical resident education. We thus sought to assess whether VR-based simulation could enhance the training of neurosurgery residents in lateral spine surgery.

METHODS

Neurosurgery residents completed a VR-based lateral spine module on lateral patient positioning and performing lateral lumbar interbody fusion using the PrecisionOS VR system on the Meta Quest 2 headset. Simulation occurred 1×/week every other week for a total of 3 simulations over 6 weeks. Pre- and postintervention surveys as well as intrasimulation performance metrics were assessed over time.

RESULTS

The majority of resident participants showed improvement in performance scores, including an automated PrecisionOS precision score, number of radiographs used within the simulation, and time to completion. All participants showed improvement in comfort with anatomic landmarks for lateral access surgery, confidence performing lateral surgery without direct supervision, and assessing fluoroscopy in spine surgery for hardware placement and image interpretation. Participant perception on the utility of VR as an educational tool also improved.

CONCLUSIONS

VR-based simulation enhanced neurosurgical residents' ability to understand lateral access surgery. Immersive surgical simulation resulted in improved resident confidence with surgical technique and workflow, perceived improvement in anatomical knowledge, and simulation performance scores. Trainee perceptions on virtual simulation and training as a curriculum supplement also improved following completion of VR training.

A systematic review of surgical simulation in gender affirmation surgery

The burgeoning field of gender affirmation surgery (GAS) has become increasingly complex, challenging plastic surgeons to meet high standards for their patients. During the COVID-19 pandemic, the emphasis on remote learning ushered in the increased use of surgical simulation training, offering residents the opportunity to trial challenging procedures before treating patients. This systematic review seeks to summarize current simulation training models used in GAS. A systematic review was conducted according to PRISMA-P guidelines using the following databases: PubMed, Medline, Scopus, Embase, Web of Science, and Cochrane. Inclusion criteria were English-language peer-reviewed articles on surgical simulation techniques or training related to the field of gender surgery. Skills and techniques taught and assessed, model type, equipment, and cost were abstracted from articles. Our search criteria identified 1650 articles, 10 of which met the inclusion criteria for data extraction. Simulation models included those that involved cadavers (n = 2), synthetic benchtop (n = 5), augmented/virtual reality (n = 2), and 3D-printed interfaces (n = 1). The most common procedure involved breast or pectoral reconstruction and/or augmentation (n = 5), followed by vaginal reconstruction (n = 3). One simulation model involved facial GAS. All models focused on surgical technique and anatomy, three on suture skills or knot-tying, and one on surgical decision-making. The evolving field of GAS requires that plastic surgery trainees be knowledgeable on surgical techniques surrounding this scope of practice. Surgical simulation not only teaches residents how to master techniques but also helps address the sensitive nature of GAS.

Neural radiance fields-based multi-view endoscopic scene reconstruction for surgical simulation

PURPOSE

In virtual surgery, the appearance of 3D models constructed from CT images lacks realism, leading to potential misunderstandings among residents. Therefore, it is crucial to reconstruct realistic endoscopic scene using multi-view images captured by an endoscope.

METHODS

We propose an Endoscope-NeRF network for implicit radiance fields reconstruction of endoscopic scene under non-fixed light source, and synthesize novel views using volume rendering. Endoscope-NeRF network with multiple MLP networks and a ray transformer network represents endoscopic scene as implicit field function with color and volume density at continuous 5D vectors (3D position and 2D direction). The final synthesized image is obtained by aggregating all sampling points on each ray of the target camera using volume rendering. Our method considers the effect of distance from the light source to the sampling point on the scene radiance.

RESULTS

Our network is validated on the lung, liver, kidney and heart of pig collected by our device. The results show that the novel views of endoscopic scene synthesized by our method outperform existing methods (NeRF and IBRNet) in terms of PSNR, SSIM, and LPIPS metrics.

CONCLUSION

Our network can effectively learn a radiance field function with generalization ability. Fine-tuning the pre-trained model on a new endoscopic scene to further optimize the neural radiance fields of the scene, which can provide more realistic, high-resolution rendered images for surgical simulation.

Surgical Artificial Intelligence in Urology: Educational Applications

Surgical education has seen immense change recently. Increased demand for iterative evaluation of trainees from medical school to independent practice has led to the generation of an overwhelming amount of data related to an individual's competency. Artificial intelligence has been proposed as a solution to automate and standardize the ability of stakeholders to assess the technical and nontechnical abilities of a surgical trainee. In both the simulation and clinical environments, evidence supports the use of machine learning algorithms to both evaluate trainee skill and provide real-time and automated feedback, enabling a shortened learning curve for many key procedural skills and ensuring patient safety.

Training simulator efficacy in developing thoracic and general surgical skills in a residency programme: a pilot study

OBJECTIVES

Virtual training simulators have been introduced in several surgical disciplines to improve residents' abilities. Through the use of the LapSim® virtual training simulator (Surgical Science, Göteborg, Sweden), this study aims to plan an effective learning path in minimally invasive thoracic and general surgery.

METHODS

All thoracic and general surgery trainees in their 1st and 2nd year of residency at the University of Insubria were enrolled and randomized into 2 groups: residents undergoing an intensive twice-a-week virtual training programme (group A: n = 8) and those undergoing a once-weekly non-intensive virtual training programme (group B: n = 9). The virtual training programme was divided into 4 modules, each of 12 weeks. In the 1st module, trainees repeated grasping, cutting, clip application, lifting and grasping, and fine dissection exercises during each training session. Seal-and-cut exercise was performed as the initial and final test. Data on surgical manoeuvres (time and on mistakes) were collected; intra- and inter-group comparisons were planned.

RESULTS

No significant differences were observed between groups A and B at the 1st session, confirming that the 2 groups had similar skills at the beginning. After 12 weeks, both groups showed improvements, but comparing data between initial and final test, only Group A registered a significant reduction in total time (P-value = 0.0015), left (P-value = 0.0017) and right (P-value = 0.0186) instrument path lengths, and in left (P-value = 0.0010) and right (P-value = 0.0073) instrument angular path lengths, demonstrating that group A acquired greater precision in surgical manoeuvres.

CONCLUSIONS

Virtual simulator training programme performed at least twice a week was effective for implementing basic surgical skills required for the trainee's professional growth. Additional virtual training modules focused on more complex exercises are planned to confirm these preliminary results.

Simulation of soft tissue deformation under physiological motion based on complementary dynamic method

BACKGROUND AND OBJECTIVE

Physiological motions have a significant impact on soft tissue deformation and accuracy of surgical procedures, which is essential for realistic surgical simulation. While existing studies offer accurate simulation of soft tissue deformation, integrating physiological motions into deformation models of soft tissue remains a challenging task.

METHODS

This paper introduces a novel deformation model, based on complementary dynamics, to animate soft tissue deformation under physiological motion. The finite element method is incorporated to accurately characterize the elastic behavior of the soft tissue. Mathematical models of physiological motion are utilized and the physiological effects are converted into displacements of a predefined set of handles within the soft tissue mesh. Complementary displacements derived from the inherent dynamics of the soft tissue are calculated, enabling the simulation of physiological motions and elastic behaviors in soft tissue deformation.

RESULTS

Experiments were conducted to evaluate the performance and effectiveness of the proposed method in simulating soft tissue deformation under physiological motion. The simulation results show that the soft tissues exhibit physiological motion that corresponds to the rhythm of arterial pressure fluctuations, heartbeat or respiratory. Furthermore, the presented method exhibits stable performance compared with existing force-based methods.

CONCLUSIONS

Both elastic behaviors and physiological motions of soft tissue deformation can be governed by the proposed method. A high degree of realistic visualization is achieved for virtual surgery simulation.

Evaluation of polyethylene terephthalate glycol (PETG), Simubone™, and photopolymer resin as 3D printed temporal bone models for surgical simulation

OBJECTIVES

Among types of 3D printing, fused deposition modeling (FDM) and digital light processing (DLP) are the most accessible, making them attractive, low-cost options for simulating surgical procedures. This study characterized and compared inexpensive, synthetic temporal bone models printed using Resin, PETG, and Simubone™.

MATERIALS AND METHODS

This study compared models made of polyethylene terephthalate glycol (PETG), Simubone™ produced from a FDM printer, and photopolymer resin from a DLP printer. These temporal bone models were processed by: (1) DICOM files from a patient's CT scan were segmented to define critical parts expected in a temporal bone surgery. (2) The model was appended with a base that articulates with a 3D-printed temporal bone holder. (3) The refined, patient-specific model was manufactured using FDM and DLP printing technologies. (4) The models were sent to evaluators, who assessed the models based on anatomic accuracy, dissection experience, and its applicability as a surgical simulation tool for temporal bone dissection.

RESULTS

The photopolymer resin outperformed PETG and Simubone™ in terms of anatomical accuracy and dissection experience. Additionally, resin and PETG were evaluated to be appropriate for simple mastoidectomy and canal wall down mastoidectomy while Simubone™ was only suitable for simple mastoidectomy. All models were unsuitable for posterior tympanotomy and labyrinthectomy.

CONCLUSIONS

Photopolymer resin and PETG have shown to be suitable materials for dissection models with 3D-printed resin models showing more accuracy in replicating anatomical structures and dissection experience. Hence, the use of 3D-printed temporal bones may be a suitable low-cost alternative to cadaveric dissection.

Porcine model for tracheostomy training: evaluation of the content and construct validity

PURPOSE

Tracheostomy is a key procedure that residents in Oto-Rhino-Laryngology, Head and Neck surgery must master as a fundamental component of their training. Swine is a potential model for tracheostomy training as it mimics human anatomy and provides realistic haptic feedback. The purpose of this study is to evaluate its content and construct validity in surgical tracheostomy training.

METHODS

We carried out training sessions on dead swine with three groups of volunteers: young residents [postgraduate year (PGY)-1 to 3], experienced residents (PGY-4 to 6) and senior surgeons. Content validity was studied using questionnaires sent to senior surgeons. Construct validity was assessed by comparing the OSATS score on video analysis, between the three groups.

RESULTS

19 individuals participated in the training sessions. OSATS score were statistically different between groups (p < 0.05) with a mean score of 19 for young residents, 24.7 for experienced residents and 31.3 for senior surgeon, with a good inter-rater reliability (Pearson coefficient > 0.9). Experienced surgeons agreed that the model was a useful training tool, strongly agreed that it improved performance, and that it would be used to train their students.

CONCLUSIONS

The dead pig is a suitable model to train for human tracheotomy, with good content and construction validity.

Gaps and priorities in innovation for children's surgery

Lack of access to pediatric medical devices and innovative technology contributes to global disparities in children's surgical care. There are currently many barriers that prevent access to these technologies in low- and middle-income countries (LMICs). Technologies that were designed for the needs of high-income countries (HICs) may not fit the resources available in LMICs. Likewise, obtaining these devices are costly and require supply chain infrastructure. Once these technologies have reached the LMIC, there are many issues with sustainability and maintenance of the devices. Ideally, devices would be created for the needs and resources of LMICs, but there are many obstacles to innovation that are imposed by institutions in both HICs and LMICs. Fortunately, there is a growing interest for development of this space, and there are many examples of current technologies that are paving the way for future innovations. Innovations in simulation-based training with incorporated learner self-assessment are needed to fast-track skills acquisition for both specialist trainees and non-specialist children's surgery providers, to scale up access for the larger population of children. Pediatric laparoscopy and imaging are some of the innovations that could make a major impact in children's surgery worldwide.

Cognitive models for mentally visualizing a sharp instrument in a blind procedure

Purpose

Our objective was to understand the cognitive strategies used by surgeons to mentally visualize navigation of a surgical instrument through blind space.

Methods

We conducted semi-structured interviews with 15 expert and novice surgeons following simulated retropubic trocar passage on 3D-printed models of pelvises segmented from preop MRIs. Midurethral sling surgery involves blind passage of a trocar among the urethra, bladder, iliac vessels, and bowel while relying primarily on haptic feedback from the suprapubic bone (SPB) for guidance. Our conceptual foundation was based on Lahav's study on blind people's mental mapping of spaces using haptic cues. Participants detailed how they mentally pictured the trocar's location relative to vital anatomy. We coded all responses and used constant comparative analysis to generate themes, confirmed with member checking.

Results

Expert and novice participants utilized multiple cognitive strategies combined with haptic feedback to accomplish safe trocar passage. Some used a step-by-step route strategy, visualizing sequential 2D axial images of anatomy adjacent to the SPB. Others used a map strategy, forming global 3D pictures. Although these mental pictures vanished when they were "lost," a safe zone could be reestablished by touching the SPB. Experts were more likely to relate their body position to the trocar path and rely on minor variations in resistance. Novices were more inclined toward backtracking of the trocar.

Conclusions

Our findings may be extended to any blind surgical procedure. Teaching visualization strategies and incorporating tactile feedback can be used intraoperatively to help learners navigate their instrument safely around vital organs.

Accuracy of hard and soft tissue prediction using three-dimensional simulation software in bimaxillary osteotomies: A systematic review

INTRODUCTION

Orthognathic surgery is considered nowadays as a revolutionary treatment option for treating skeletal discrepancies and severe malocclusions in the sagittal, vertical and transverse dimensions. This surgery allows both the restoration of facial harmony and the achievement of satisfactory dental occlusion. The technology of computer-assisted surgeries including virtual surgical simulation programs and planning software greatly contributes to providing a three-dimensional simulation and precise mobilization of the maxilla and/or mandible, thus allowing the prediction of the final outcome in soft tissues. This study aims to systematically review the available scientific literature about the accuracy of the hard and soft tissue predictions delivered by the many promoted three-dimensional simulation software.

MATERIAL AND METHODS

An electronic search was conducted on various databases: Medline via PubMed, The Cochrane Library, EBSCO-host, and Web of Science. The search was established on a well-defined research question following PICO principle: population, intervention, comparator and outcome. Search evaluation and the assessment of risk of bias were undertaken in each study following its type and design.

RESULTS

Fifteen studies were included for qualitative analysis. Seven studies evaluated the accuracy of soft tissue prediction, seven focused more on the accuracy of hard tissue and one study assessed both hard and soft tissue prediction accuracy delivered by the simulation software. Moreover, three studies were judged to be low risk and four were classified as high risk. Included studies revealed that hard tissue prediction is highly accurate and reliable, leading to clinically acceptable results. Yet, soft tissue prediction is unclear due to various factors that bias its results. Caution should therefore be taken when providing information about the soft tissue planning to patients.

CONCLUSIONS

Computer assisted 3D simulation protocols allow for more precise repositioning of the maxilla and/or mandible compared to conventional 2D methods. However, 3D soft tissue prediction using simulation software remains less accurate, especially in the labial region.

Recent advances in computerized imaging and its vital roles in liver disease diagnosis, preoperative planning, and interventional liver surgery: A review

The earliest and most accurate detection of the pathological manifestations of hepatic diseases ensures effective treatments and thus positive prognostic outcomes. In clinical settings, screening and determining the extent of a pathology are prominent factors in preparing remedial agents and administering appropriate therapeutic procedures. Moreover, in a patient undergoing liver resection, a realistic preoperative simulation of the subject-specific anatomy and physiology also plays a vital part in conducting initial assessments, making surgical decisions during the procedure, and anticipating postoperative results. Conventionally, various medical imaging modalities, e.g., computed tomography, magnetic resonance imaging, and positron emission tomography, have been employed to assist in these tasks. In fact, several standardized procedures, such as lesion detection and liver segmentation, are also incorporated into prominent commercial software packages. Thus far, most integrated software as a medical device typically involves tedious interactions from the physician, such as manual delineation and empirical adjustments, as per a given patient. With the rapid progress in digital health approaches, especially medical image analysis, a wide range of computer algorithms have been proposed to facilitate those procedures. They include pattern recognition of a liver, its periphery, and lesion, as well as pre- and postoperative simulations. Prior to clinical adoption, however, software must conform to regulatory requirements set by the governing agency, for instance, valid clinical association and analytical and clinical validation. Therefore, this paper provides a detailed account and discussion of the state-of-the-art methods for liver image analyses, visualization, and simulation in the literature. Emphasis is placed upon their concepts, algorithmic classifications, merits, limitations, clinical considerations, and future research trends.

Expert laparoscopist performance on virtual reality simulation tasks with and without haptic features

BACKGROUND

Virtual reality (VR) simulation for laparoscopic training is available with and without haptic feedback features. Currently, there is limited data on haptic feedback's effect on skill development. Our objective is to compare expert laparoscopists' skills characteristics using VR delivered laparoscopic tasks via haptic and nonhaptic laparoscopic surgical interfaces.

METHODS

Five expert laparoscopists performed seven skills tasks on two laparoscopic simulators, one with and one without haptic features. Tasks consisted of 2-handed instrument navigation, retraction and exposure, cutting, electrosurgery, and complicated object positioning. Laparoscopists alternated platforms at default difficulty settings. Metrics included time, economy of movement, completed task elements, and errors. Progressive change in performance for the final three iterations were determined by repeated measures ANOVA. Iteration quartile means were determined and compared using paired t-tests.

RESULTS

No change in performance was noted in the last three iterations for any metric. There were no significant differences between platforms on the final two quartiles for most metrics except avoidance of over-stretch error for retraction; and cutting task was significantly better with haptics on all iteration quartiles (p < 0.03). Economy of movement was significantly better with haptics for both hands for clip application (p < 0.01) and better for right hand on complex object positioning (p < 0.05). Accuracy was better with haptics for retraction and cutting (p < 0.05) and clip application (p < 0.05).

CONCLUSION

Results showed higher performance in accuracy, efficient instrument motion, and avoidance of excessive traction force on selected tasks performed on VR simulator with haptic feedback compared to those performed without haptics feedback. Laparoscopic surgeons interpreted machine-generated haptic cues appropriately and resulted in better performance with VR task requirements. However, our results do not demonstrate an advantage in skills acquisition, which requires additional study.

Validation of a multidisciplinary virtual reality (VR) robotic surgical curriculum

The objective is to identify whether trainees demonstrate improvement in a standardized knot-tying task as assessed by Global Evaluative Assessment of Robotic Skills (GEARS) score after completion of a virtual reality (VR) robotic curriculum. An IRB-exempt prospective study was conducted with surgical trainees from August 2021 to February 2023. Participants initially performed a baseline robotic suturing task in which they were instructed to tie interrupted square knots in 10 min. Participants then completed a virtual reality simulation curriculum involving 23 exercises until they achieved 90% proficiency on all tasks. Participants then repeated the suturing task. Pre- and post-curriculum suturing tasks were recorded, de-identified, and scored by expert graders using a GEARS score. Trainees from three academic centers were invited to participate. Medical students (MS1-MS3) and surgical residents from gynecology, urology, and general surgery were invited to participate. Twenty-five trainees completed the pre-curriculum suturing task, the VR curriculum, and the post-curriculum suturing task. Trainees demonstrated significant improvement in their post-test GEARS score by 2.43 points (p < 0.05) and were able to tie three additional knots within 10 min after completion of the curriculum (p < 0.05). Trainees also demonstrated a faster time to complete first knot (114 s improvement, p < 0.05) after completion of the curriculum. All participants agreed or strongly agreed that completion of the robotic curriculum helped them feel more comfortable using the robotic console, and improved their robotic surgical skills. Surgical trainees and medical students with limited prior robotic surgical experience demonstrated objective improvement after completion of a standardized VR curriculum.

Fast and precise collision detection for detailed and complex physiological structures

BACKGROUND AND OBJECTIVES

Virtual reality has been proved indispensable in computer-assisted surgery, especially for surgical planning, and simulation systems. Collision detection is an essential part of surgery simulators and its accuracy and computational efficiency play a decisive role in the fidelity of simulations. Nevertheless, current collision detection methods in surgical simulation and planning struggle to meet precise requirements, especially for detailed and complex physiological structures. To address this, the primary objective of this study was to develop a new algorithm that enables fast and precise collision detection to facilitate the improvement of the realism of virtual reality surgical procedures.

METHODS

The method consists of two main parts, bounding spheres formation and two-level collision detection. A specified surface subdivision method is devised to reduce the radius of basic bounding spheres formed by circumcenters of underlying triangles. The spheres are then clustered and adjusted to obtain a compact personalized hierarchy whose position is updated in real time during surgical simulation, followed by two-level collision detection. Triangular facets with collision potential through interaction between hierarchies and then accurate results are obtained by means of precise detection phase. The effectiveness of the algorithm was evaluated in various models and surgical scenarios and was compared with prior relevant implementations.

RESULTS

Results on multiple models demonstrated that the method can generate a personalized hierarchy with fewer and smaller bounding spheres for tight wrapping. Simulation experiments proved that the proposed approach is significantly superior to comparable methods under the premise of error-free detection, even for severe model-model collision.

CONCLUSIONS

The algorithm proposed through this study enables higher numerical efficiency and detection accuracy, which is capable of significantly enlarging the fidelity/realism of haptic simulators and surgical planning methods.

Surgeon estimation of retropubic trocar position in blind 3D space

INTRODUCTION AND HYPOTHESIS

Retropubic midurethral sling surgery involves the blind passage of trocars near vital organs. We quantified the proximity of surgeons' mental representation of trocar position relative to actual position using a pelvis simulation platform. We hypothesized that novice surgeons, compared with experts, would estimate the trocar's location to be further from the actual location.

METHODS

Novice and expert surgeons performed bilateral retropubic trocar passes of a Gynecare TVT trocar (#810041B-#810,051) on the simulation platform. We measured the trocar tip's position using a motion capture system, and recorded vocalizations when they perceived contacting the bone and crossing three landmark-oriented planes. We calculated differences (∆Bone, ∆Turn, ∆Top, ∆Pop) between vocalization times and when the trocar crossed the corresponding plane. We performed Mann-Whitney and Chi-squared tests to investigate differences between novices and experts and Levene's test to assess equality of variances for subject-level variation.

RESULTS

A total of 34 trials, including 22 expert and 12 novice trials, were performed by six participants. ∆Bone was significantly smaller among novice surgeons (1.27 vs 2.81 s, p=0.013). There were no significant differences in the remaining three deltas or in vocalizing early versus late. Levene's test revealed no significant differences in within-subject variability for any of the four deltas. Novices passed the trocar anterior to the pubic bone on three passes.

CONCLUSIONS

Novices were similar to expert surgeons in their estimation of the trocar's location and may have relied more heavily on anticipatory mechanisms to compensate for lack of experience. Teaching surgeons should make sure the novice surgeon trocar pass starts posterior to the bone.

3D Printed Larynx as a Novel Simulation Tool for Window Elaboration in Medialization Laryngoplasty

OBJECTIVE

Surgical simulation training in residents has declined due to the limited exposure to cadaveric specimens. Three-dimensional (3D)-printing technology is rapidly taking an important role in different medical areas, especially in surgical specialties. It provides an alternative for resident simulation practices and for developing surgical skills before exposure to real settings. The elaboration of the thyroid window in the medialization laryngoplasty procedure requires high technical precision and experience for better outcomes.

METHODS

The computer-based 3D reconstruction model was created using computed tomograph scan images from a standard larynx. The final model was created using a deposition modeling 3D printing technique with polylactic acid filament. The model was tested for surgical simulation practice in three otolaryngology residency programs in Bogotá, Colombia.

RESULTS

The model had similar anatomic detail and it was considered very useful, safe, and relevant for surgical simulation.

CONCLUSIONS

3D printed models are a cost-effective alternative for resident training.

Development and validation of a hybrid simulator for ultrasound-guided laparoscopic common bile duct exploration

BACKGROUND

Ultrasound-guided laparoscopic common bile duct exploration (LCBDE) is the surgical management of choledocholithiasis. The procedure presents significant benefits to patients but still fails to be generalised because of the complex set of skills it requires. A simulator for ultrasound-guided LCBDE would allow trainee surgeons as well as experienced surgeons who perform this surgery seldomly to practice and gain confidence.

METHODS

This article presents the development and validation of an easily reproducible hybrid simulator for ultrasound-guided LCBDE which integrates real and virtual components of the task. We first developed a physical model made of silicone. The fabrication technique is replicable and allows quick and easy production of multiple models. We then applied virtual components onto the model to create training for laparoscopic ultrasound examination. Combined with a commercially available lap-trainer and surgical equipment, the model can be used for training the fundamental steps of the surgery through the trans-cystic or trans-choledochal approaches. The simulator was evaluated through face, content, and construct validation.

RESULTS

Two novices, eight middle grades, and three experts were recruited to test the simulator. The results of the face validation showed that the surgeons found the model realistic visually and felt realistic when performing the different steps of the surgery. The content validation indicated the usefulness of having a training system to practice the choledochotomy, the choledochoscopy and stone retrieval, and the suturing. The construct validation highlighted the ability of the simulator to differentiate between surgeons with various levels of expertise.

CONCLUSIONS

The hybrid simulator presented is a low-cost yet realistic model which allows the surgeons to practice the technical skills required for trans-cystic and trans-choledochal ultrasound-guided LCBDE.

System identification and simulation of soft tissue force feedback in a spine surgical simulator

Surgical simulators are being introduced as training modalities for surgeons. This paper aims to evaluate dynamic models used to convey force feedback from puncturing the soft tissue during a spine surgical simulation. The force feedback of the tissue is treated as a dynamic system. This is done by performing classical system identification across a bandwidth of frequencies on a tissue analogue and fitting that behaviour to dynamic viscoelastic models. The models that are tested are an inverted linear model, the Maxwell model, the Kelvin-Boltzmann (KB) model, and a higher-order blackbox (HO) model. Several error metrics such as percent variance accounted for (%VAF) are determined to measure solution accuracy. The force feedback models are programmed into a surgical simulator and tested with study participants who rated them based on how well the identified models match the behaviour of the rubber tissue analogue. The highest %VAF is 82.64% when the tissue is modelled as the HO model. Statistically significant differences (p < 0.05) are found between all model ratings from participants except between the HO model and the KB model. However, the HO model has the highest percentage (37.8%) of participants who rank its performance as the closest to the tissue analogue compared to the other force feedback models. The more accurately the dynamic behaviour resembles the tissue analogue, the higher the model was rated by study participants. This study highlights the importance of utilizing dynamic signals to generate dynamic models of soft tissue for spine surgical simulators.

An ex vivo model for education and training of bilateral cleft lip surgery

BACKGROUND

Bilateral cleft lip surgery is very challenging and requires a high level of skill, knowledge and experience. Existing high-fidelity simulation models that can be used by novice cleft surgeons to gain experience and expand their knowledge are rare and expensive. In this study, we developed a bilateral cleft lip model using porcine snout discs, which are available anywhere and inexpensive.

METHODS

Anatomic reference points of a patient with a bilateral cleft lip were superimposed with landmarks of the porcine snout disc on a foil template. The template was used to construct an ex vivo bilateral cleft lip model. Surgery was performed on the model according to Millard and the surgical steps were photodocumented analogous to two clinical cases of bilateral cleft lip surgery. The suitability of the model was further tested by twelve participants and evaluated using self-assessment questionnaires.

RESULTS

The bilateral cleft lip ex vivo model made of a porcine snout disc proved to be a suitable model with very low cost and ease of fabrication, as the template is reusable on any snout disc. The Millard procedure was successfully performed and the surgical steps of the lip plasty were simulated close to the clinical situation. Regarding the nasal reconstruction, the model lacks three-dimensionality. As a training model, it enhanced the participants comprehension of cleft surgery as well as their surgical skills. All participants rated the model as valuable for teaching and training.

CONCLUSIONS

The porcine snout discs can be used as a useful ex vivo model for bilateral cleft lip surgery with limitations in the construction of the nose, which cannot be realistically performed with the model due to anatomical differences with humans. Benefits include a realistic tissue feel, the simulation of a multi-layered lip construction, a wide and rapid availability and low cost. This allows the model to be used by novice surgeons also in low-income countries. It is therefore useful as a training model for gaining experience, but also as a model for refining, testing and evaluating surgical techniques for bilateral lip plasty.

Simulation-based training in cardiac surgery: a systematic review

OBJECTIVES

The increase in the complexity of operations, the rising quest for improved outcomes and the scrutiny of surgical practice and its associated complications have led to a decreased educational value of in-patient surgical training within cardiac surgery. Simulation-based training has emerged as an adjunct to the apprenticeship model. In the following review, we aimed to evaluate the currently available evidence regarding simulation-based training in cardiac surgery.

METHODS

A systematic database search was conducted as per PRISMA guidelines, of original articles that explored the use of simulation-based training in adult cardiac surgery programs in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to 2022. Data extraction covered the study characteristics, simulation modality, main methodology and main outcomes.

RESULTS

Our search yielded 341 articles, of which 28 studies were included in this review. Three main areas of focus were identified: (i) validity testing of the models; (ii) impact on surgeons' skills; and (iii) impact on clinical practice. Fouteen studies reported animal-based models and 14 reported on non-tissue-based models covering a wide spectrum of surgical operations. The results of the included studies suggest that validity assessment is scarce within the field, being carried out for only 4 of the models. Nonetheless, all studies reported improvement in trainees' confidence, clinical knowledge and surgical skills (including accuracy, speed, dexterity) of trainees both at senior and junior levels. The direct clinical impact included initiation of minimally invasive programmes and improved board exam pass rates, and creating positive behavioural changes to minimize further cardiovascular risk.

CONCLUSIONS

Surgical simulation has been shown to provide substantial benefits to trainees. Further evidence is needed to explore its direct impact on clinical practice.

A novel low-cost model of superficial abscess for trainee education in incision and drainage

Background

Proficiency in ultrasound usage is quickly becoming an expectation in multiple residency programs: emergency medicine, obstetrics-gynecology, surgery, and internal medicine. There is a lack of affordable training devices for ultrasound training and identification of superficial fluid collections. We sought to develop a model for trainee education in ultrasound usage, identification of superficial fluid collection, aspiration, and incision & drainage (I&D).

Materials & methods

Commercially available products were used to develop a novel, low-cost model for ultrasound-guided aspiration and I&D of an abscess. A latex balloon embedded in silicone gel construct simulated a superficial fluid collection when examined with an ultrasound probe and monitor. A 18-gauge needle on a 10-cc syringe were used for aspiration, and a 15-blade disposal scalpel with 0.25″ packing strip used for I&D.

Results

Approximately six hours are required to generate 24 individual models of a superficial abscess. Following an initial investment, each model costs less than $1 USD to produce. Compared to commercially available models, this represents a significant savings. This model was utilized during the medical school academic year as a teaching aid for medical students to simulate ultrasound-guided identification, aspiration, and incision and drainage of a superficial abscess.

Conclusions

We successfully produced an affordable, low-cost model of a superficial fluid collection for training in ultrasound usage, aspiration, and I&D. The model represents significant savings over commercially available alternatives and can be easily replicated for trainee education.

Emergency burn education: Evaluating a surgical simulation-based intervention

INTRODUCTION

Medical simulation has provided favorable outcomes in the improvement of clinical competence at both the undergraduate and postgraduate levels. The recall of information demonstrably increases when it has been taught in environments similar to the workplace. This study aimed to evaluate the role of a one-day burn simulation session in improving students' knowledge of burn management and interest in plastic surgery as a specialty.

METHOD

A one-day course was designed to deliver multiple lectures covering surgical topics such as the classification and management of burns, followed by a series of practical workshops. Participants were instructed to undergo a pre-course knowledge assessment and a survey focusing on interest in plastic surgery. Students were subsequently instructed to complete a post-course assessment and a survey of knowledge and confidence in managing burns as well as interest in plastic surgery both immediately and 6 weeks post-course.

RESULTS

The students' knowledge demonstrated a 54.2% increase in the post-course assessment (p < 0.01). 27% of participants (n = 14) participated in a 6-week post-course quiz. The knowledge assessment of these participants at 6 weeks post-course also demonstrated a sustained increase of 61.0% (p < 0.01). Interest in plastic surgery was increased by 31.4% post-course (p < 0.01). At 6 weeks post-course, a sustained increase of 14.7% was demonstrated in comparison to pre-course data (p = 0.03).

CONCLUSION

Simulation teaching provides good outcomes in both information retention and interest in plastic surgery as a specialty. Therefore, medical school curriculums may benefit from including burn simulations.

Revitalizing pancreas transplantation: creation of a hands-on training course for pancreas allograft procurement, backbench preparation, and transplantation

Despite a steady increase in the number of organs available for transplant in the United States, over the last two decades there has been a precipitous decrease in the annual number of pancreas transplants performed. One overlooked consequence of this decline in pancreas transplant volume has been a decrease in experience in proper pancreas procurement and transplantation techniques for transplant surgeons as well as fewer trained abdominal transplant fellows entering the workforce certified for pancreas procurement and transplantation, with those achieving certification having less-developed judgment, skills, and experience. To augment current fellowship training and provide a concentrated experience in pancreas procurement and transplantation, the ASTS developed a hands-on surgical skills workshop focused on proper techniques for pancreas allograft procurement and backbench preparation.

GlobalSurgBox: A Portable Surgical Simulator for Surgical Trainees Worldwide

OBJECTIVES

Identify barriers to surgical simulation in multiple countries across the income spectrum. Evaluate whether a novel, portable surgical simulator (GlobalSurgBox) would be valuable to surgical trainees and overcome these barriers.

DESIGN

Trainees from high-, middle-, and low-income countries were instructed on how to perform surgical skills using the GlobalSurgBox. Participants were sent an anonymized survey after 1 week to evaluate practicality and helpfulness of the trainer.

SETTING

Academic medical centers in 3 countries: USA, Kenya, and Rwanda.

PARTICIPANTS

48 medical students, 48 surgery residents, 3 medical officers, and 3 cardiothoracic surgery fellows.

RESULTS

99.0% of respondents agreed surgical simulation was an important aspect of surgical education. Despite 60.8% having access to simulation resources, only 3 of 40 (7.5%) US trainees, 2 of 12 (16.7%) of Kenyan trainees, and 1 of 10 (10.0%) Rwandan trainees used these resources routinely. 38 (95.0%) US trainees, 9 (75.0%) Kenyan trainees, and 8 (80.0%) Rwandan trainees with access to simulation resources stated there were barriers to using them. The frequently cited barriers included lack of convenient access and lack of time. After using the GlobalSurgBox, 5 (7.8%) US participants, 0 (0%) Kenyan participants, and 5 (38.5%) Rwandan participants reported lack of convenient access as a continued barrier to simulation. 52 (81.3%) US trainees, 24 (96.0%) Kenyan trainees, and 12 (92.3%) Rwandan trainees stated the GlobalSurgBox was a good facsimile of the operating room. 59 (92.2%) US trainees, 24 (96.0%) Kenyan trainees, and 13 (100%) Rwandan trainees stated the GlobalSurgBox better prepared them for clinical settings.

CONCLUSIONS

A majority of trainees across all 3 countries reported multiple barriers to simulation in their current surgical training. The GlobalSurgBox eliminates many of these barriers by providing a portable, affordable, and realistic way to practice skills needed in the operating room.

Clinical Application of Resection Process Map as a novel surgical guide in thoracic surgery

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Resection Process Map is a surgical simulation system that uses preoperative three-dimensional computed tomography. Unlike the usual static simulation, this system provides surgeons an individualized dynamic deformation of the lung parenchyma and vessels. Resection Process Map was first introduced in 2020. Although the intraoperative usefulness of this system has been evaluated experimentally, there have been no reports on its clinical use. Herein, we presented in detail the first experience on Resection Process Map during robot-assisted anatomical lung resection in the real clinical setting.

CLINICAL REGISTRATION NUMBER

2015-04587082. The study protocol was approved by the institutional review board of Nagoya University School of Medicine (2015-04587082).

Modeling fibrous soft tissue dissection with elastic-plastic deformation for simulation of brain tumor removal

BACKGROUND AND OBJECTIVE

Realistic modeling the dissection of brain tissue is of key importance for simulation of brain tumor removal in virtual neurosurgery systems. However, existing methods are unable to characterize inelastic behaviors of brain tissue, such as plastic deformation and dissection evolution, making it ineffective in simulating brain tumor removal procedures.

METHODS

In this paper, a model of fibrous soft tissue dissection for the simulation of brain tumor removal is proposed. A dissection variable of representative volume element is used to characterize the dissection state of the fibrous soft tissue. The evolution of dissection with elastic-plastic deformation under the effects of external loads is presented.

RESULTS

Simulation results show that the proposed model provides realistic, stable and intuitive results in the simulation of fracture in fibrous soft tissues. As the external load increases, the fibrous soft tissue begins to crack, with the cracks growing and multiplying until they eventually merge to form a fracture. The proposed model is incorporated into the simulation of brain tumor removal.

CONCLUSIONS

The experimental results demonstrate the feasibility of modeling fibrous soft tissue dissection with elastic-plastic deformation. A relative high degree of realistic visual feedback is achieved.

Investigation of the Use of Hollow Elastic Biomodels Produced by Additive Manufacturing for Clip Choice and Surgical Simulation in Microsurgery for Intracranial Aneurysms

BACKGROUND

Intracranial aneurysms (IAs) are dilatations of the cerebral arteries, whose treatment is commonly based on the implant of a metallic clip on the aneurysm neck. Despite the dissection and understanding of the surgical anatomy of the IA when often only parts of it are visible, the choice of the ideal clip to be used is one of the surgical difficulties. Although current imaging tests guarantee IA visualization, currently there is no planning method that allows for a real three-dimensional (3D) visualization for optimal choice of clip prior to surgery. The aim of this study is to evaluate whether IA biomodels generated by additive manufacturing methods are useful for surgical clip selection in microsurgeries for IA.

METHODS

Three-dimensional (3D) IA biomodels of 10 patients with IA were evaluated using computerized tomography, surgical microscope, and 3D printer. The research was divided into 4 phases as follows: development of the 3D biomodels, evaluation of the biomodel dimensional characteristics, surgical planning evaluation with the biomodel and its clipping effectiveness, and evaluation of the actual surgical simulation process within the models.

RESULTS

Ten 3D biomodels were obtained, made of a malleable and hollow part, formed by the IA and related arteries, and another rigid part, mimicking the skull and other arteries of the skull base. Based on these 3D models, 10 clips were chosen during the surgical planning, and all exactly matched the clip characteristics used during the actual surgeries. The surgical simulation with the biomodels performed by 2 neurosurgeons still in training obtained 100% accuracy in the identification of the clips that were eventually used during the actual surgeries.

CONCLUSIONS

3D biomodels generated by additive manufacturing methods were effective for surgical clip selection in microsurgeries for IA, reducing surgical time, increasing cerebral angioarchitecture understanding, and providing more safety in this type of surgery.

Micro-mechanism study on tissue removal behavior under medical waterjet impact using coupled SPH-FEM

To fully grasp the numerical characteristics of the interaction process between medical waterjet and soft tissue, the smoothed particle hydrodynamics (SPH)-finite element method (FEM) was used in the simulation of this complex process to avoid the unstable error caused by indirect measurement in experiments. The SPH was applied to the numerical simulation of medical waterjet, and a three-dimensional model of gelatin sample was proposed with the FEM. The impact process between two extremely deformed materials was reproduced, and the established model was verified by comparison with experimental data; the comparison showed relatively consistent results. The separation effect under three operating modes was deduced with the stress and strain range. For the vertical impact condition, the higher the waterjet impact pressure is, the higher the biological tissue deformation bulge height is. For oblique intrusion, the longitudinal separation rate decreases and the kerf width increases with the increase of the incident angle. For the moving impact condition, with the increase of the waterjet moving speed, the longitudinal high-stress distribution range of the impact object decreases slightly.

EndoTrainer: a novel hybrid training platform for endoscopic surgery

PURPOSE

Endoscopy implies high demanding procedures, and their practice requires structured formation curricula supported by adequate training platforms. Physical platforms are the most standardised solution for surgical training, but over the last few years, virtual platforms have been progressively introduced. This research work presents a new hybrid, physic-virtual, endoscopic training platform that exploits the benefits of the two kind of platforms combining realistic tools and phantoms together with the capacity of measuring all relevant parameters along the execution of the exercises and of providing an objective assessment performance.

METHODS

The developed platform, EndoTrainer, has been designed to train and assess surgical skills in hysteroscopy and cystoscopy following a structured curricula. The initial development and validation is focused on hysteroscopic exercises proposed in the Gynaecological Endoscopic Surgical Education and Assessment (GESEA) Certification Programme from The Academy and European Society for Gynaecological Endoscopy (ESGE) and analyses the obtained results of an extensive study with 80 gynaecologists executing 30 trials of the standard 30 degree endoscope navigation exercise.

RESULTS

The experiments demonstrate the benefits of the presented hybrid platform. Multi-variable statistical analysis points out that all subjects have obtained statistically significant improvement in all relevant parameters: shorter and safer trajectories, improved 30-degree endoscope navigation, accurate positioning over the targets and reduction of the execution time.

CONCLUSION

This paper presents a new hybrid approach for training, and evaluating whether it provides an objectivable improvement of camera navigation endoscopic basic skills. The obtained results demonstrate the initial hypothesis: all subjects have improved their camera handling and navigation skills.

Buccal rotation for wholly impacted maxillary third molar extraction

BACKGROUND

Extracting wholly impacted maxillary 3rd molars faces difficulty due to the narrow surgical field, adjacent teeth resistances and risk of oroantral communication. This study is designed to introduce and evaluate the applicability of a novel method-buccal rotation to extract maxillary 3rd molars.

MATERIALS AND METHODS

In this cohort study, from October 1st 2020 to September 30th 2021, 72 wholly impacted maxillary 3rd molars were included. Based on the crowns with coronal 1/3, middle 1/3, apical 1/3 of the adjacent teeth roots, teeth were classified into position I, II, III. Based on the angles < 30°, ≥ 30°but < 60°, ≥ 60° to the adjacent teeth, teeth were classified into angulation A, B, C. Traditional method and novel method-buccal rotation were applied based on the surgical simulations. Surgical results were recorded. To analyze the data, Chi-square test was applied.

RESULTS

82.00% of teeth in position I and 50.00% in position II were designed to use traditional method, 83.33% in position III were using the novel method (p < 0.05). 81.25% of teeth in angulation A and 52.63% in angulation B were designed to use traditional method, 80.00% in angulation C were using the novel method (p < 0.05). Four cases got temporary complications.

CONCLUSION

Buccal rotation was applicable to extract the deep impacted maxillary third molars with large angles towards the adjacent teeth.

Virtual vascular surgery interest group during the coronavirus disease 2019 pandemic

OBJECTIVES

Early exposure to vascular surgery at the medical student level positively influences one's decision to apply into an integrated vascular surgery residency program. Vascular surgery interest groups (VSIGs) are student-run and aim to facilitate such exposure, traditionally via in-person events. Social distancing during the coronavirus disease 2019 pandemic disrupted these interactions. This is a description of the virtual activities of a VSIG group during the 2020-2021 academic year and highlights their impact among medical students.

METHODS

The virtual activities of the VSIG at the Yale School of Medicine were reviewed. Students received surveys prior and after activities to assess their impact. Preactivity and postactivity surveys using Likert scale (1 = completely disagree; 5 = completely agree) were administered and compared. Statistical significance was achieved with a P value of less than .05.

RESULTS

A total of five virtual events were held: an Introductory Session (October 2020), a Simulation Session (November 2020), a Research Night (January 2021), a Journal Club (February 2021), and a National Match Panel (April 2021). The surveys of three events (Introductory Session, Simulation Session, and National Match Panel) were analyzed. Attendance at these events were 18, 55, and 103 respectively. The average presurvey response rate was 51.2% and the average postsurvey response rate was 27.46%. Students agreed that the Introductory Session increased their knowledge about vascular surgery as a subspecialty (4.22 ± 0.67) and that the session was valuable to their time (4.33 ± 1.00). The Simulation Session increased student's comfort with knot tying from 1.73 ± 0.89 to 3.21 ± 1.25 (P < .001). Students reported an increased understanding of residency program selection (2.39 ± 1.10 vs 3.21 ± 1.12; P = .018), the Electronic Residency Application Service application (2.16 ± 1.01 vs 3.00 ± 0.88; P = .007), and letters of recommendation (2.45 ± 1.07 vs 3.14 ± 1.17; P = .04). Students particularly had a significant increase in the understanding of the logistics of residency interviews, which were held virtually that year for the first time (1.84 ± 0.96 vs 3.29 ± 1.20; P < .001).

CONCLUSIONS

Virtual VSIG activities were feasible and effective during the pandemic in promoting student engagement and interest in vascular surgery. Despite lifting social distancing measures, the virtual format could become a valuable tool to expand outreach efforts of the vascular surgery community to recruit talented medical students.

Video-based coaching for surgical residents: a systematic review and meta-analysis

BACKGROUND

Video-based coaching (VBC) is used to supplement current teaching methods in surgical education and may be useful in competency-based frameworks. Whether VBC can effectively improve surgical skill in surgical residents has yet to be fully elucidated. The objective of this study is to compare surgical residents receiving and not receiving VBC in terms of technical surgical skill.

METHODS

The following databases were searched from database inception to October 2021: Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed. Articles were included if they were randomized controlled trials (RCTs) comparing surgical residents receiving and not receiving VBC. The primary outcome, as defined prior to data collection, was change in objective measures of technical surgical skill following implementation of either VBC or control. A pairwise meta-analyses using inverse variance random effects was performed. Standardized mean differences (SMD) were used as the primary outcome measure to account for differences in objective surgical skill evaluation tools.

RESULTS

From 2734 citations, 11 RCTs with 157 residents receiving VBC and 141 residents receiving standard surgical teaching without VBC were included. There was no significant difference in post-coaching scores on objective surgical skill evaluation tools between groups (SMD 0.53, 95% CI 0.00 to 1.01, p = 0.05, I² = 74%). The improvement in scores pre- and post-intervention was significantly greater in residents receiving VBC compared to those not receiving VBC (SMD 1.62, 95% CI 0.62 to 2.63, p = 0.002, I² = 85%). These results were unchanged with leave-one-out sensitivity analysis and subgroup analysis according to operative setting.

CONCLUSION

VBC can improve objective surgical skills in surgical residents of various levels. The benefit may be most substantial for trainees with lower baseline levels of objective skill. Further studies are required to determine the impact of VBC on competency-based frameworks.

The user experience design of a novel microscope within SurgiSim, a virtual reality surgical simulator

PURPOSE

Virtual reality (VR) simulation has the potential to advance surgical education, procedural planning, and intraoperative guidance. "SurgiSim" is a VR platform developed for the rehearsal of complex procedures using patient-specific anatomy, high-fidelity stereoscopic graphics, and haptic feedback. SurgiSim is the first VR simulator to include a virtual operating room microscope. We describe the process of designing and refining the VR microscope user experience (UX) and user interaction (UI) to optimize surgical rehearsal and education.

METHODS

Human-centered VR design principles were applied in the design of the SurgiSim microscope to optimize the user's sense of presence. Throughout the UX's development, the team of developers met regularly with surgeons to gather end-user feedback. Supplemental testing was performed on four participants.

RESULTS

Through observation and participant feedback, we made iterative design upgrades to the SurgiSim platform. We identified the following key characteristics of the VR microscope UI: overall appearance, hand controller interface, and microscope movement.

CONCLUSION

Our design process identified challenges arising from the disparity between VR and physical environments that pertain to microscope education and deployment. These roadblocks were addressed using creative solutions. Future studies will investigate the efficacy of VR surgical microscope training on real-world microscope skills as assessed by validated performance metrics.

Properties and Implementation of 3-Dimensionally Printed Models in Spine Surgery: A Mixed-Methods Review With Meta-Analysis

OBJECTIVE

Spine surgery addresses a wide range of spinal pathologies. Potential applications of 3-dimensional (3D) printed in spine surgery are broad, encompassing education, planning, and simulation. The objective of this study was to explore how 3D-printed spine models are implemented in spine surgery and their clinical applications.

METHODS

Methods were combined to create a scoping review with meta-analyses. PubMed, EMBASE, the Cochrane Library, and Scopus databases were searched from 2011 to 7 September 2021. Results were screened independently by 2 reviewers. Studies utilizing 3D-printed spine models in spine surgery were included. Articles describing drill guides, implants, or nonoriginal research were excluded. Data were extracted according to reporting guidelines in relation to study information, use of model, 3D printer and printing material, design features of the model, and clinical use/patient-related outcomes. Meta-analyses were performed using random-effects models.

RESULTS

Forty articles were included in the review, 3 of which were included in the meta-analysis. Primary use of the spine models included preoperative planning, education, and simulation. Six printing technologies were utilized. A range of substrates were used to recreate the spine and regional pathology. Models used for preoperative and intraoperative planning showed reductions in key surgical performance indicators. Generally, feedback for the tactility, utility, and education use of models was favorable.

CONCLUSIONS

Replicating realistic spine models for operative planning, education, and training is invaluable in a subspeciality where mistakes can have devastating repercussions. Future study should evaluate the cost-effectiveness and the impact spine models have of spine surgery outcomes.

External validation of a low fidelity dry-lab platform to enhance loupes surgical skills techniques for hypospadias repair

INTRODUCTION

Hypospadias repair is an index pediatric urology procedure that requires trainee familiarity with surgical loupes. A previous low-fidelity, 6-step curriculum was proposed that deconstructed the most important steps of loupe surgery. We expanded on this curriculum with an intermediate-fidelity silicone hypospadias model and designed an abbreviated version of the 6-step curriculum to precede the hypospadias repair simulation.

OBJECTIVE

To assess the validity of our prior, low-fidelity conceptual model using the metric of improved performance on the intermediate-fidelity silicone hypospadias model.

STUDY DESIGN

A silicone model was first prototyped with the design software Solidworks™, and then fabricated using a cast made of a mixture of silicone rubbers designed to function like skin and soft tissue (Mold Star 20T, Dragon skin FX-pro and Slacker). Casts were used to create the penile shaft model and the dorsal hooded foreskin model. The urethral plate was cast separately on a flat surface. The model was then assembled by hand. The model used for simulation included the penile shaft and urethral plate, while the dorsal-hooded foreskin was prepared to simulate the penile anatomy separately. Trainees were then divided into two groups. Group 1 practiced the low-fidelity curriculum (3 tasks) and then performed dissection of the urethral plate and suturing using the intermediate-fidelity hypospadias model. Group 2 practiced hypospadias repair prior to the low-fidelity curriculum. Both groups' models were scored by 3 blinded urologists. Trainees were then asked to complete a post simulation satisfaction survey. Data analysis was performed in IBM SPSS Statistics for Macintosh (Version 28.0 Armonk, NY: IBM Corp).

RESULTS

Twenty-two candidates across Wisconsin, USA, and Dublin, Ireland participated in the study. This included 7 s-year residents, 9 third-year residents, 2 fourth-year residents, and 3 fifth-year residents. Both Groups 1 and 2 had a similar distribution of trainees (p = 0.60). Group 1 outperformed group 2 in all tasks (p < 0.05, Table 1). Trainees reported that the platform was very useful (91%).

DISCUSSION

Our curriculum showed improvement in trainee ability and comfort to perform hypospadias repair. Advantages of such a simulated curriculum include improving current resident training in microsurgery, improving surgical ergonomics for trainees prior to real-time experience, and decreasing the learning curve for trainees pursuing pediatric urology.

CONCLUSION

An intermediate-fidelity hypospadias platform externally validates the conceptual model implemented in the low-fidelity loupes curriculum. This appears to lead to improvement in loupe surgical skills regardless of trainee level.

Artificial intelligence in laparoscopic simulation: a promising future for large-scale automated evaluations

Introduction

A limitation to expanding laparoscopic simulation training programs is the scarcity of expert evaluators. In 2019, a new digital platform for remote and asynchronous laparoscopic simulation training was validated. Through this platform, 369 trainees have been trained in 14 institutions across Latin America, collecting 6729 videos of laparoscopic training exercises. The use of artificial intelligence (AI) has recently emerged in surgical simulation, showing usefulness in training assessment, virtual reality scenarios, and laparoscopic virtual reality simulation. An AI algorithm to assess basic laparoscopic simulation training exercises was developed. This study aimed to analyze the agreement between this AI algorithm and expert evaluators in assessing basic laparoscopic-simulated training exercises.

Methods

The AI algorithm was trained using 400-bean drop (BD) and 480-peg transfer (PT) videos and tested using 64-BD and 43-PT randomly selected videos, not previously used to train the algorithm. The agreement between AI and expert evaluators from the digital platform (EE) was then analyzed. The exercises being assessed involve using laparoscopic graspers to move objects across an acrylic board without dropping any objects in a determined time (BD < 24 s, PT < 55 s). The AI algorithm can detect object movement, identify if objects have fallen, track grasper clamps location, and measure exercise time. Cohen’s Kappa test was used to evaluate the agreement between AI assessments and those performed by EE, using a pass/fail nomenclature based on the time to complete the exercise.

Results

After the algorithm was trained, 79.69% and 93.02% agreement were observed in BD and PT, respectively. The Kappa coefficients test observed for BD and PT were 0.59 (moderate agreement) and 0.86 (almost perfect agreement), respectively.

Conclusion

This first approach of AI use in basic laparoscopic skills simulated training assessment shows promising results, providing a preliminary framework to expand the use of AI to other basic laparoscopic skills exercises.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09576-1.

Viability and characterization trial of a novel method as an alternative to formaldehyde and Walter-Thiel cadaveric preservation for medical education and surgical simulation

INTRODUCTION

Despite its toxic and carcinogenic nature, formaldehyde is a widely used reactant for specimen preservation. With the need of specimens for both anatomical and surgical training, alternative preservation solutions (PS) have been proposed, however, their use is limited due to high costs and complexity. Hence, a new formaldehyde-free solution (FFS) is evaluated as a potential alternative for anatomical and surgical training.

METHODS

Qualitative and Quantitative data were acquired. Specimens preserved using three different methods were selected. Flexibility was measured by joints goniometry and pneumoperitoneum pressures were evaluated followed by an exploratory laparoscopy. Undergraduate student's perceptions on cadavers preserved with different PS were obtained using surveys and focus groups.

RESULTS

The main reason why cadaveric specimens were considered as useful tools was the perceived interaction with real tissues and the 'practical' concept of getting in touch with what students would be facing in the future as physicians, what we call "hands on" activities. FFS treated specimens showed better joint-movement ranges in comparison to other methods and pneumoperitoneum was acquired after 5mmHg CO₂ pressure. Students appreciated working with corpses regardless the technique used, however FFS specimens were defined as less uncomfortable, while presenting no sensory discomfort.

CONCLUSIONS

Even though alternative PS are effective, high costs and complexity restrict their usage. Cadavers preserved with FFS had similar range of movements compared with Thiel. Students preferred to work with FFS rather than FF due to flexibility, color, and no sensorial hassles. Thus, we propose FFS as viable alternative to traditional PS.

Scotland's "Incentivised Laparoscopy Practice" programme: Engaging trainees with take-home laparoscopy simulation

BACKGROUND

The transfer validity of portable laparoscopy simulation is well established. However, attempts to integrate take-home simulation into surgical training have met with inconsistent engagement worldwide, as for example in our 2014-15 study of an Incentivised Laparoscopy Practice programme (ILPv1). Drawing on learning from our subsequent multi-centre study examining barriers and facilitators, we revised the programme for 2018 onwards. We now report on engagement with the 2018-2022 versions of this home-based simulation programme (ILP v2.1-2.3).

METHODS

In ILP v2.1-2.3, three consecutive year-groups of new-start Core Surgical Trainees (n = 48, 46 and 53) were loaned portable simulators. The 6-month education programme included induction, technical support, and intermittent feedback. Six tasks were prescribed, with video instruction and charting of metric scores. Video uploads were required and scored by faculty. A pass resulted in an eCertificate, expected at Annual Review (but not mandatory for progression). ILP was set within a wider reform, "Improving Surgical Training".

RESULTS

ILP v2.1-2.3 saw pass rates of 94%, 76% and 70% respectively (45/48, 35/46 and 37/53 trainees), compared with only 26% (7/27) in ILP v1, despite now including some trainees not intending careers in laparoscopic specialties. The ILP v2.2 group all reported their engagement with the whole simulation strategy was hampered by the COVID19 pandemic.

CONCLUSIONS

Simply providing take-home simulators, no matter how good, is not enough. To achieve trainee engagement, a whole programme is required, with motivated learners, individual and group practice, intermittent feedback, and clear goals and assessments. ILP is a complex intervention, best understood as a "reform within a reform, within a context."

Using open surgery simulation kinematic data for tool and gesture recognition

PURPOSE

The use of motion sensors is emerging as a means for measuring surgical performance. Motion sensors are typically used for calculating performance metrics and assessing skill. The aim of this study was to identify surgical gestures and tools used during an open surgery suturing simulation based on motion sensor data.

METHODS

Twenty-five participants performed a suturing task on a variable tissue simulator. Electromagnetic motion sensors were used to measure their performance. The current study compares GRU and LSTM networks, which are known to perform well on other kinematic datasets, as well as MS-TCN++, which was developed for video data and was adapted in this work for motion sensors data. Finally, we extended all architectures for multi-tasking.

RESULTS

In the gesture recognition task the MS-TCN++ has the highest performance with accuracy of [Formula: see text] and F1-Macro of [Formula: see text], edit distance of [Formula: see text] and F1@10 of [Formula: see text] In the tool usage recognition task for the right hand, MS-TCN++ performs the best in most metrics with an accuracy score of [Formula: see text], F1-Macro of [Formula: see text], F1@10 of [Formula: see text], and F1@25 of [Formula: see text]. The multi-task GRU performs best in all metrics in the left-hand case, with an accuracy of [Formula: see text], edit distance of [Formula: see text], F1-Macro of [Formula: see text], F1@10 of [Formula: see text], and F1@25 of [Formula: see text].

CONCLUSION

In this study, using motion sensor data, we automatically identified the surgical gestures and the tools used during an open surgery suturing simulation. Our methods may be used for computing more detailed performance metrics and assisting in automatic workflow analysis. MS-TCN++ performed better in gesture recognition as well as right-hand tool recognition, while the multi-task GRU provided better results in the left-hand case. It should be noted that our multi-task GRU network is significantly smaller and has achieved competitive results in the rest of the tasks as well.

A computer based facial flaps simulator using projective dynamics

BACKGROUND AND OBJECTIVES

Interactive surgical simulation using the finite element method to model human skin mechanics has been an elusive goal. Mass-spring networks, while fast, do not provide the required accuracy.

METHODS

This paper presents an interactive, cognitive, facial flaps simulator based on a projective dynamics computational framework. Projective dynamics is able to generate rapid, stable results following changes to the facial soft tissues created by the surgeon, even in the face of sudden increases in skin resistance as its stretch limit is reached or collision between tissues occurs. Our prior work with the finite element method had been hampered by these considerations. Surgical tools are provided for; skin incision, undermining, deep tissue cutting, and excision. A spring-like "skin hook" is used for retraction. Spring-based sutures can be placed individually or automatically placed as a row between cardinal sutures.

RESULTS

Examples of an Abbe/Estlander lip reconstruction, a paramedian forehead flap to the nose, a retroauricular flap reconstruction of the external ear, and a cervico-facial flap reconstruction of a cheek defect are presented.

CONCLUSIONS

Projective dynamics has significant advantages over mass-spring and finite element methods as the physics backbone for interactive soft tissue surgical simulation.

Skeletal muscle surrogates for the acquisition of muscle repair skills in upper limb surgery

INTRODUCTION

The required fidelity of synthetic materials in surgical simulators to teach tissue handling and repair requirements should be as accurate as possible. There is a poor understanding of the relationship between choice of muscle surrogates and training outcome for trainee surgeons. To address this, the mechanical characteristics of several candidate synthetic muscle surrogates were measured, and their subjective biofidelity was qualitatively assessed by surgeons.

METHODS

Silicone was selected after assessing several material options and 16 silicone-based surrogates were evaluated. Three of the closest samples to muscle (Samples 1.1, 1.2, 1.3) and one with inserted longitudinal fibres (1.2F) were mechanically tested in the following: compression and tension, needle puncture force and suture pull-out in comparison with real muscle. The four samples were evaluated by 17 Plastic and Orthopaedic surgeons to determine their views of the fidelity with regard to the handling properties, needle insertion and ease of suture pull-out.

RESULTS

The mechanical testing showed the surrogates exhibited varying characteristics that matched some of the properties of muscle, though none recreated all the mechanical characteristics of native muscle. Good biofidelity was generally achieved for compression stiffness and needle puncture force, but it was evident that tensile stiff was too low for all samples. The pull-out forces were variable and too low, except for the sample with longitudinal fibres. In the qualitative assessment, the overall median scores for the four surrogate samples were all between 30 and 32 (possible range 9-45), indicating limited differentiation of the samples tested by the surgeons.

CONCLUSIONS

The surrogate materials showed a range of mechanical properties bracketing those of real muscle, thus presenting a suitable combination of candidates for use in simulators to attain the requirements as set out in the learning outcomes of muscle repair. However, despite significant mechanical differences between the samples, all surgeons found the samples to be similar to each other.

Starting a medical 3D printing lab for otolaryngology-head and neck surgery collaboration

OBJECTIVE

To evaluate the different strategies for developing and maintaining a 3-dimensional (3D) printing lab.

METHODS

We evaluated two printing labs and compared their structure, integration, and production.

RESULTS

While one lab was initiated by a clinician and the other by a technical expert, both labs followed a similar series of steps to develop their lab. Each identified a key clinical need, developed a collaborative team, found financial support, and discovered options for sustainability.

CONCLUSIONS

While there is no correct path for developing a 3D printing lab, depending on the existing infrastructure and the clinical need, one may choose a certain initial structure for a lab while following a list of common necessary steps.

Percutaneous peritoneal drain placement: A pilot study of pediatric surgery simulation-based training for general surgery residents

INTRODUCTION

General surgery residents often feel unprepared to perform pediatric surgery procedures since case volume and experience may be low. Previously, we successfully implemented a simulation-based training (SBT) module for placement of a silastic silo for gastroschisis. Therefore, we designed a single institution pilot study to assess whether SBT for placement of a percutaneous peritoneal drain for perforated necrotizing enterocolitis (NEC) was feasible and lead to skill acquisition and increased confidence.

METHODS

Our newly created NEC module within our pediatric surgery SBT curriculum for general surgery residents was used. Residents completed two simulation sessions three months apart with confidence testing before and after each session. Skill acquisition and performance were assessed using a standardized case scenario and procedure checklist. Changes in residents' confidence and performance were determined using Wilcoxon Signed-Rank Tests.

RESULTS

Nine post-graduate-year three general surgery residents completed this curriculum. Following completion, residents reported improved confidence completing each step of the procedure initially (p = 0.005) and at 3 months (p = 0.008) with improved technical scores (p = 0.011). The number of residents deemed proficient significantly improved (p = 0.031).

CONCLUSION

Implementation of SBT module for perforated NEC was feasible and improved residents' confidence and proficiency completing the procedure.

Three-dimensional printed moulds to obtain silicone hearts with congenital defects for paediatric heart-surgeon training

OBJECTIVES

Many types of congenital heart disease are amenable to surgical repair or palliation. The procedures are often challenging and require specific surgical training, with limited real-life exposure and often costly simulation options. Our objective was to create realistic and affordable 3D simulation models of the heart and vessels to improve training.

METHODS

We created moulded vessel models using several materials, to identify the material that best replicated human vascular tissue. This material was then used to make more vessels to train residents in cannulation procedures. Magnetic resonance imaging views of a 23-month-old patient with double-outlet right ventricle were segmented using free open-source software. Re-usable moulds produced by 3D printing served to create a silicone model of the heart, with the same material as the vessels, which was used by a heart surgeon to simulate a Rastelli procedure.

RESULTS

The best material was a soft elastic silicone (Shore A hardness 8). Training on the vessel models decreased the residents' procedural time and improved their grades on a performance rating scale. The surgeon evaluated the moulded heart model as realistic and was able to perform the Rastelli procedure on it. Even if the valves were poorly represented, it was found to be useful for preintervention training.

CONCLUSIONS

By using free segmentation software, a relatively low-cost silicone and a technique based on re-usable moulds, the cost of obtaining heart models suitable for training in congenital heart defect surgery can be substantially decreased.