Clinical Cadavers as a Simulation Resource for Procedural Learning

Cadaveric analysis of surgical techniques and working space for retroperitoneal tumors as model for improving resection of neuroblastoma

PURPOSE

Neuroblastoma, the most common extracranial solid tumor in children under 5 years, often surrounds visceral arteries. This study aimed to analyze the working space provided by standardized surgical techniques at key arterial landmarks in adult cadavers.

METHODS

We assessed in eight adult cadavers the mobilization of the left colon, spleen and pancreas, right colon, duodenum and mesenteric root, access to the bursa omentalis. The average working space score (AWSS) was evaluated at the left and right renal artery, left and right side of the coeliac trunk, superior mesenteric and common hepatic artery. The score was defined as: (0) vessel not visible, (1) working space at the vessel ≤ 1x diameter of the aorta, (2) < 3x the diameter of the aorta, (3) ≥ 3x diameter of the aorta.

RESULTS

The maximum AWSS of 3 was achieved at key vascular landmarks through specific mobilization techniques.

CONCLUSION

Additional mobilization of spleen, pancreas and mesenteric root and access to the bursa omentalis increase surgical working space at major visceral arteries. The results of our investigation provide surgeons with a useful guide to prepare for abdominal neuroblastoma resection.

From FUSE to a hands-on electrosurgery course using a cadaveric model

INTRODUCTION

Surgical procedures in contemporary practice frequently employ energy-based devices, yet comprehensive education surrounding their safety and effectiveness remains deficient. We propose an innovative course for residents that aims to provide basic electrosurgery knowledge and promote the safe use of these devices.

METHODS

We developed a simulated training course for first-year general surgery and orthopedic residents. First, a survey was conducted regarding their knowledge perception about energy devices. The course consisted of two online theoretical sessions, followed by three in-person practical sessions. First-year residents performed three video-recorded attempts using a cadaveric model and were assessed through a digital platform using the Objective Structured Assessment of Technical Skill (OSATS), a Specific Rating Scale (SRS), and a surgical energy-based devices scale (SEBS). Third-year residents were recruited as a control group.

RESULTS

The study included 20 first-year residents and 5 third-year residents. First-year residents perceived a knowledge gap regarding energy devices. Regarding practical performance, both OSATS and checklist scores were statistically different between novices at their first attempt and the control group. When we analyzed the novice's performance, we found a significant increase in OSATS (13 vs 21), SRS (13 vs 17.5), and SEBS (5 vs 7) pre- and post-training scores. The amount of feedback referred to skin burns with the electro-scalpel reduced from 18 feedbacks in the first attempt to 2 in the third attempt (p-value = 0.0002). When comparing the final session of novices with the control group, no differences were found in the SRS (p = 0.22) or SEBS (p = 0.97), but differences remained in OSATS (p = 0.017).

CONCLUSION

This study supports the implementation of structured education in electrosurgery among surgical trainees. By teaching first-year residents about electrosurgery, they can acquire a skill set equivalent to that of third-year residents. The integration of such courses can mitigate complications associated with energy device misuse, ultimately enhancing patient safety.

Enhancing Botulinum Toxin Injection Precision: The Efficacy of a Single Cadaveric Ultrasound Training Intervention for Improved Anatomical Localization

Ultrasound guidance can enhance existing landmark-based injection methods, even through a brief and single exposure during a cadaveric training course. A total of twelve participants were enrolled in this training program, comprising nine physical medicine and rehabilitation specialists, one pediatrician, and two physician assistants. For each participant, one upper-limb muscle and one lower-limb muscle were randomly chosen from the preselected muscle group. Subsequently, participants were tasked with injecting both of their chosen cadaveric muscles with 1 mL of acrylic paint using a manual needle palpation technique, relying solely on their knowledge of anatomic landmarks. Participants then underwent a personalized, one-to-one ultrasound teaching session, lasting approximately five minutes, conducted by two highly experienced instructors. Following this instructive phase, participants were tasked with a second round of injections, targeting the same two muscles in the lower and upper limbs. However, this time, the injections were performed using anatomical landmarks and ultrasound guidance. To facilitate differentiation from the initial injections, a distinct color of acrylic paint was employed. When employing the anatomical landmark-based approach, the overall success rate for injections was 67%, with 16 out of 24 targeted muscles accurately injected. With the incorporation of ultrasound guidance, the success rate was 92%, precisely targeting 22 out of the 24 muscles under examination. There was an improvement in injection accuracy achievable through the integration of ultrasound guidance, even with minimal training exposure. Our single cadaveric ultra-sound training program contributes valuable insights to the utilization of ultrasound for anatomy training to help optimize the targeting of BoNT-A.

Does a junior doctor focused 'Bootcamp' improve the confidence and preparedness of newly appointed ENT registrars to perform their job roles?

BACKGROUND

To assess changes in confidence and preparedness after conducting a 2-day induction bootcamp for novice Ear Nose and Throat (ENT) first year specialty trainee registrars (ST3s) in the United Kingdom (UK). The bootcamp covered common ENT presentations on the ward, and in the elective and emergency settings.

METHODS

A total of 32 trainees (ST3 or research fellow) voluntarily registered via an online application form to the Southern ST3 accelerated learning course bootcamp through ENT UK. ENT UK is a membership body that supports ENT trainees throughout their careers. They completed a two-day bootcamp that was hosted at St Mary's Hospital, London and 10 skills sessions were delivered by either a senior ENT registrar or an ENT consultant. A pre-session questionnaire was distributed to all participants and a post-session questionnaire was provided that assessed the changes in confidence and preparedness of the participants, if any. The responses were scored by a 10-point Likert scale. Only participants who fully completed the pre and post questionnaire were included, which was 29 in total.

RESULTS

Participants self-reported a significant increase in confidence (p < 0.001) and preparedness (p < 0.001) following the bootcamp course. The greatest improvements in comparison to all other stations were self-preparedness in the rigid bronchoscopy station and self-confidence in the sphenopalatine artery (SPA) ligation station.

CONCLUSION

The use of a two-day bootcamp improved confidence and preparedness of managing common ENT presentations in the ward, elective and emergency settings for ENT ST3s. It provides a useful adjunct in the acquisition of technical and non-technical skills alongside the traditional surgical apprenticeship. In the future, more work is required to assess the impact of bootcamps on patient outcomes and long-term benefits on trainees' skill retention and clinical proficiency.

Development and Preliminary Evaluation of A Soft Tissue Microtia Simulator

Surgical simulation has been used extensively for learning microtia reconstruction and has almost exclusively involved framework creation. However, soft tissue reconstruction in microtia is equally challenging and would benefit from a simulation platform. This study aimed to describe the development and preliminary evaluation of a high-fidelity soft tissue microtia simulator. Three-dimensional modeling software, fused deposition 3-dimensional printing, adhesive techniques, silicones, and polyurethane rubbers were utilized to create a right lobular-type microtia simulator that comprises skin, subcutaneous tissue, and cartilage. Two expert microtia surgeons performed a microtia reconstruction on the simulator and evaluated its value and realism using a Likert-type questionnaire. The surgeons utilized a previously developed synthetic framework and successfully performed the critical steps of the soft tissue reconstruction, including marking, incising, dissection, removal of the cartilage remnant, drain insertion, insertion of the framework, closing of the skin, and demonstration of the soft tissue conforming over the framework using suction. A preliminary assessment of the simulator demonstrated that the simulator is anatomically accurate, realistic, and highly valuable as a training tool. A high-fidelity soft tissue microtia simulator was successfully developed and tested. The simulator provides a valuable training platform for learning a critical component of microtia reconstruction.

Advancements in surgical education: exploring animal and simulation models in fetal and neonatal surgery training

Introduction

Surgical education is undergoing a transformation, moving away from traditional models towards more modern approaches that integrate experiential and didactic methods. This shift is particularly pertinent in the realm of fetal and neonatal surgery, where specialized training is crucial. Historical training methods, such as cadaveric dissection, have been prevalent for centuries, but newer innovations, including animal and non-animal simulation models, are gaining prominence. This manuscript aims to explore the use of both animal and non-animal models in surgical education, with a specific focus on fetal and neonatal surgery.

Animal models

The use of animal models in surgical training has a long history, dating back to Halsted's introduction in 1889. These models, often utilizing large animals like swine and dogs, offer valuable insights into fetal and neonatal surgeries. They allow for the study of long-term outcomes and the simulation of various diseases and anomalies, providing essential training experiences not readily available in human surgeries. However, there are notable limitations, including anatomical and physiological differences from humans, ethical considerations, and substantial infrastructure and maintenance costs.

Simulation models

Simulation-based training offers several benefits, including standardized and safe learning environments without risks to real patients. Bench models, using synthetic materials or non-living animal tissue, provide cost-effective options for skills development. Virtual reality and 3-D printing technologies further enhance simulation experiences, allowing for the replication of complex clinical scenarios and patient-specific anatomies. While these models offer significant advantages, they lack the complexity of biological systems found in animal models.

Conclusion

In conclusion, both animal and non-animal simulation models play crucial roles in enhancing surgical education, particularly in fetal and neonatal surgery. While advancements in non-animal technologies are important for ethical reasons, the continued necessity of animal models in certain areas should be acknowledged. By responsibly integrating these models into training programs, surgical education can be further enriched while upholding ethical standards and ensuring optimal patient outcomes.

Orthopaedic Hand Surgical Simulation Training: A Review

In recent years, new orthopaedic surgical simulation and virtual reality (VR) training models have emerged to provide unlimited education medium to an unlimited number of trainees with no time limit, especially in response to trainee work-hour restrictions. Surgical simulators range from simple wooden boxes to animal and cadaver models to three-dimensional-printed and VR simulators. The coronavirus disease 2019 pandemic further highlighted the need for at-home learning tools for orthopaedic surgical trainees. Advancement in simulating shoulder and knee arthroscopies using VR simulators surpasses the other fields in orthopaedic surgery. Despite the high degree of precision needed to operate at a microscopic level involving vessels, nerves, and the small bones of the hand, the simulation tools have limited advancement in the field of orthopaedic hand surgery. This narrative review summarizes the status of surgical simulation and training techniques available to orthopaedic hand surgical trainees, factors affecting their application, and areas in hand surgery that still lag behind their surgical subspecialty counterparts.

Immersive virtual reality in orthopedic surgery as elective subject for medical students : First experiences in curricular teaching

BACKGROUND

Virtual reality (VR) simulators have been introduced for skills training in various medical disciplines to create an approximately realistic environment without the risk of patient harm and have improved to more immersive VR (iVR) simulators at affordable costs. There is evidence that training on VR simulators improves technical skills but its use in orthopedic training programs and especially in curricular teaching sessions for medical students are currently not well established. The aim of this study was to describe the implementation of a VR operating theater as an elective course for undergraduate medical students and to evaluate its effect on student learning.

METHODS

An elective course for 12 students was implemented during the summer semester of 2023. Using Oculus Quest 2 headsets (Reality Labs, Meta Platforms, USA) and controllers and the PrecisionOS platform, they were able to train five different surgical procedures. The courses were accompanied by weekly topic discussions and instructional videos. Students were assigned to two groups: group VR vs. group non-VR. The groups were switched after 5 weeks. User feedback and performance development (theoretical and procedural surgical knowledge) after VR training were assessed using three questionnaires.

RESULTS

The students highly appreciated the implementation of VR training into their curriculum and 91% stated that they would opt for further VR training. All students stated that VR training improved their understanding of surgical procedures and that it should be obligatory in surgical training for undergraduate medical students. After 5 weeks of training, students in the VR group achieved significantly better results (100 out of maximum 180 points) than the non-VR group (70 points, p = 0.0495) in procedural surgical knowledge. After completion of the VR training the VR group achieved 106 points and the non-VR group 104 points (p = 0.8564). The procedural knowledge for non-VR group after 5 weeks significantly improved after VR training from 70 to 106 points (p = 0.0087).

CONCLUSION

The iVR can be easily integrated into the curriculum of medical students and is highly appreciated by the participants. The iVR statistically improves the procedural knowledge of surgical steps compared to conventional teaching methods. Further implementation of iVR training in curricular teaching of medical students should be considered.

Modification of an Airway Training Mannequin to Teach Engagement of the Hyoepiglottic Ligament

Audience

This airway trainer modification is designed to instruct all levels of training in emergency medicine in order to familiarize trainees with airway anatomy and obtain superior views of the glottic inlet.

Introduction

During intubation with a standard geometry laryngoscope, such as the Macintosh blade, placement of the distal end of the blade within the vallecula and engagement of the median glossoepiglottic fold, also referred to as the midline vallecular fold (MVF), has long been championed by experts in airway management for its ability to improve glottic inlet visualization. This notion was further supported by the recent publication of a retrospective video review by Driver et al.1 Unfortunately, airway anatomy, including engagement of the MVF, does not receive the emphasis it deserves during intubation training of emergency medicine residents. Emergency physicians often have limited time to perform complete airway examinations, but a sound recognition and appreciation of the laryngeal inlet can serve as a roadmap to optimal laryngoscopy.2Recent advancements in airway education emphasize visualization of airway anatomy with review of video laryngoscopy (VL) recordings to identify routine VL errors in vallecula manipulation, such as failure to engage the MVF. 3 Simulation can continue to play an essential role in enhancing trainees' airway skills. Current airway trainers lack functional fidelity components, such an engageable MVF, resulting in a missed opportunity to teach airway skills and anatomy in a safe and controlled setting.4, 5 To address these concerns, we modified an existing airway task trainer with the addition of a simulated MVF to expose trainees to airway anatomy and adequate MVF engagement resulting in epiglottic elevation.

Educational Objectives

By the end of this education session, participants should be able to:Identify relevant airway anatomy during intubation, including base of the tongue, epiglottis, midline vallecular fold, anterior arytenoids.Appreciate the value of a stepwise anatomically guided approach to intubation.Become familiar with the midline vallecular fold and underlying anatomy, including the hyoepiglottic ligament, and how proper placement of the laryngoscope can result in improved glottic visualization.

Educational Methods

The TrueCorp AirSim airway task trainer was modified with the addition of a simulated MVF. Prior to the modification described here, there were no dynamic trainers with the functional fidelity needed to teach trainees how to engage the MVF with proper placement of the distal tip of the laryngoscope. Once the trainer was created, learners are introduced to relevant anatomy through the initial lecture to unsure baseline knowledge. During the lecture, videos and images are reviewed to demonstrate the importance of an anatomical roadmap to successful intubation. Learners then practiced with the modified task trainer to gain hands-on experience with laryngoscope placement and improved glottic visualization. A short verbal debriefing was performed at the end of the skills session to address any remaining questions.

Research Methods

Pre- and post-simulation surveys were completed by attendees of a weekly didactic session, ranging from medical students, PGY 1-4 emergency medicine residents, and emergency medicine attending physicians. Pre- and post-simulation familiarity with airway anatomy and comfortability with MVF engagement was assessed using a 5-point Likert scale.

Results

Twenty-six participants ranging from medical students to attending physicians completed a pre- and post-simulation survey. Overall, feedback from leaners was positive. Learners were excited to learn new airway management techniques and requested an expansion of current airway curriculum based on the success of this implementation.

Discussion

This modified task trainer places an emphasis on teaching airway anatomy to trainees with the addition of functional fidelity by adding an engageable element providing the trainee with feedback on successful placement of the laryngoscope. This simple and cost-effective modification can add value to existing airway management curriculums by serving as a visual cue of airway anatomy and instructing trainees on proper placement of the laryngoscope. Our results showed participants experienced increased comfort with airway anatomy recognition and engagement of MVF for difficult intubations. Participants found the trainer effective with the simulated MVF resulting in glottic elevation and recommended this for future simulation. Participants were eager to learn additional airway techniques to improve their laryngoscopy skills, suggesting an area of growth for emergency medicine didactic curriculums.

Topics

Airway, midline vallecular fold, anatomy, difficult airway, education.

Human dissection for anesthesiology resident training augments anatomical knowledge and clinical skills

Anatomy is an essential component of clinical anesthesiology. The use of simulated patients and alternative materials, including embalmed human bodies, have become increasingly common during resident physician training due to the deemphasis on anatomical education during undergraduate medical training. In this report, the need for a more extensive review of relevant anatomy for the practice of anesthesiology was addressed by the design, evaluation, and dissemination of a human dissection course for procedural training of anesthesiology residents. The course utilized "freedom art" embalmed human bodies that allowed trainees to perform ultrasound-based regional and neuraxial techniques followed by detailed dissections of critical anatomy. One hundred and four residents participated in workshops and small group discussions and were evaluated using pre- and post-course assessments. A variety of clinical techniques were performed on the bodies, including regional blocks and neuraxial catheter placement. Insertion of peripheral/neuraxial catheters was successful, with dissections demonstrating the expected placement. Assessment scores improved following the course (pre-course mean 52.7%, standard deviation (σ) 13.1%; post-course mean 72.2%, σ 11.6%; t-test p < 0.0001) and feedback highlighted the usefulness and clinical relevance of course content. The ability to correlate ultrasound imaging with subsequent dissections of the "blocked" area and visualization of dye staining was extremely relevant for spatial understanding of the anatomy relevant for the clinical practice of these techniques. This manuscript demonstrates successful implementation of a comprehensive course for anesthesiology resident physicians to address gaps in undergraduate anatomical education and suggests that broader adoption of dissection courses may be beneficial for training anesthesiologists.

Negotiating humanity: an ethnography of cadaver-based simulation

Human body donation (HBD) serves an essential function in many medical schools, particularly in institutions where people engage in cadaver-based simulation (CBS) as a pedagogical approach. The people who facilitate HBD and CBS have a highly specialized skill set, yet their expertise remains largely unacknowledged, and takes place out of sight from the broader medical school community. This manuscript, based on a two-year practice-based ethnography (Structured Observations n = 68 h, Unstructured Observations n = 150 + hours; Interviews n = 24; and Document/Policy Analysis n = 14) illuminates the complex work of HBD. We identify three primary functions of HBD and CBS (1. Cadaver Intake & Administration, 2. Cadaver Preparation, and 3. Cadaver-Based Pedagogy). We describe how medical educators involved in CBS have developed a skillset specific to their role: negotiating humanity.

Comparing the Efficacy of a New Clinical Skills Model with a Traditional Method to Teach Tube Feeding of an Avian Patient

Interactive clinical skills models have been demonstrated to be useful for teaching medical and veterinary clinical skills, yet to date, very few exist for teaching skills relevant to zoological companion animals and wildlife species including birds. This two-part study aimed to create, develop, and validate a model. Interviews and a survey were conducted using veterinary and wildlife professionals to select an avian clinical skill that is challenging and performed frequently. Tube/gavage feeding, or "crop tubing" satisfied both criteria; on average it was performed 71 times a year by surveyed respondents was rated 3.4/9 for difficulty of teaching and 3.5/9 for difficulty of learning. Therefore, a new model of a bird, made from a soft toy, silicone, and 3D printed parts, was designed to train students to perform this technique. Forty-two participants were recruited and divided into two groups; one used the model the other watched an instructional video on crop tubing. The students completed a self-evaluated confidence questionnaire, before and after, using either resource. They then performed the technique on a dead bird and their proficiency at 10 different actions that comprised the technique was evaluated by two assessors. The model group performed significantly better than the video group on all evaluated actions (U ≤ 143.5, p ≤ .0031), and reported significantly higher confidence (U = 129.5, p = 0.018). In conclusion, the newly developed model in combination with an instruction booklet offers an effective and inexpensive alternative way to teach crop tubing in a teaching environment, without compromising animal welfare.

International Learner Perceptions, Educational Value, and Cost Associated With the Use of Start-to-Finish Surgical Simulation Compared With Cadaveric Models

BACKGROUND

Graduate surgical education is highly variable across regions and institutions regarding case volume and degree of trainee participation in each case. Dedicated educational curriculum using cadaveric tissue has been shown to enhance graduate surgical training, however with associated financial and utility burden to the institution.

OBJECTIVE

To investigate the utility of educational and cost applications of a novel method of combining mixed organic hydrogel polymers and 3-dimensional printed anatomic structures to create a complete "start-to-finish" simulation for resident education in spinal anatomy, instrumentation, and surgical techniques.

METHODS

This qualitative pilot study investigated 14 international participants on achievement of objective and personal learning goals in a standardized curriculum using biomimetic simulation compared with cadaveric tissue. A questionnaire was developed to examine trainee evaluation of individual anatomic components of the biomimetic simulators compared with previous experience with cadaveric tissue.

RESULTS

A total of 210 responses were acquired from 14 participants. Six participants originated from US residency education programs and 8 from transcontinental residency programs. Survey results for the simulation session revealed high user satisfaction. Score averages for each portion of the simulation session indicated learner validation of anatomic features for the simulation compared with previous cadaveric experience. Cost analysis resulted in an estimated savings of $10 833.00 for this single simulation session compared with previous cadaveric tissue sessions.

CONCLUSION

The results of this study indicate a strong potential of establishing biomimetic simulation as a cost-effective and high-quality alternative to cadaveric tissue for the instruction of fundamental spine surgical techniques.

Leading Transformation in Medical Education Through Extended Reality

Extended reality (XR) has exponentially developed over the past decades to incorporate technology whereby users can visualise, explore, and interact with 3-dimensional-generated computer environments, and superimpose virtual reality (VR) onto real-world environments, thus displaying information and data on various levels of the reality-virtuality continuum. In the context of medicine, VR tools allow for anatomical assessment and diagnosis, surgical training through lifelike procedural simulations, planning of surgeries and biopsies, intraprocedural guidance, and medical education. The following chapter aims to provide an overview of the currently available evidence and perspectives on the application of XR within medical education. It will focus on undergraduate and postgraduate teaching, medical education within Low-Middle Income Countries, key practical steps in implementing a successful XR programme, and the limitations and future of extended reality within medical education.

Human body donation and surgical training: a narrative review with global perspectives

Utilization of human material in surgical simulation training has been well-established as an effective teaching method. Despite the value of donor-based surgical simulation training, its application may be hampered by difficulties regarding access to donated bodies. Therefore, the aim of this review is to assess body donation and body acquisition practices with regard to surgical simulation training programs around the world. The results of this review highlight discrepancies regarding body donation practices and surgical simulation programs among continents and countries. The utilization of donor bodies in surgical simulation appears to mirror body donation practices. In countries that rely mostly or exclusively upon unclaimed bodies or executed criminals, there are scant reports of donor-based surgical simulation programs. In countries where willed-body donation is the principal source of human material, there tend to be many surgical simulation programs that incorporate human material as part of surgical training. This review suggests that, in anatomical and surgical education, the utilization of active willed-body donation programs, as opposed to the utilization of unclaimed human bodies, positively corresponds with the development of beneficial donor-based surgical simulation programs. Likewise, donor-based surgical simulation training programs may have an influence on the perpetualization of willed-body donations.

The Lifecycle of a Clinical Cadaver: A Practice-Based Ethnography

PhenomenonCadavers have long played an important and complex role in medical education. While research on cadaver-based simulation has largely focused on exploring student attitudes and reactions or measuring improvements in procedural performance, the ethical, philosophical, and experiential aspects of teaching and learning with cadavers are rarely discussed. In this paper, we shed new light on the fascinating philosophical moves in which people engage each and every time they find themselves face to face with a cadaver. ApproachOver a two-year period (2018/19-2019/20), we applied ethnographic methods (137 hours of observation, 24 interviews, and the analysis of 22 documents) to shadow the educational cadaver through the practical stages involved in cadaver-based simulation: 1. cadaver preparation, 2. cadaver-based skill practice with physicians and residents, and 3. interment and memorial services. We used Deleuze and Guattari's concepts of becoming and acts of creation to trace the ontological "lifecycle" of an educational cadaver as embedded within everyday work practices. FindingsWe delineated six sub-phases of the lifecycle, through which the cadaver transformed ontologically from person to donor, body, cadaver, educational cadaver, teacher, and loved one/legacy. These shifts involved a network of bureaucratic, technical, educational, and humanistic practices that shaped the way the cadaver was perceived and acted upon at different moments in the lifecycle. By highlighting, at each phase, 1) the ontological transitions of the cadaver, itself, and 2) the practices, events, settings, and people involved in each of these transitions, we explored questions of "being" as it related to the ontological ambiguity of the cadaver: its conceptualization as both person and tool, simultaneously representing life and death. InsightsEngaging deeply with the philosophical questions of cadaver-based simulation (CBS) helped us conceptualize the lifecycle as a series of meaningful and purposeful acts of becoming. Following the cadaver from program entry to interment allowed us to contemplate how its ontological ambiguity shapes every aspect of cadaver-based simulation. We found that in discussions of fidelity in medical simulation, beyond both the physical and functional, it is possible to conceive of a third type: ontological. The humanness of the cadaver makes CBS a unique, irreplaceable, and inherently philosophical, practice.

Assessment of open surgery suturing skill: Simulator platform, force-based, and motion-based metrics

Objective

This paper focuses on simulator-based assessment of open surgery suturing skill. We introduce a new surgical simulator designed to collect synchronized force, motion, video and touch data during a radial suturing task adapted from the Fundamentals of Vascular Surgery (FVS) skill assessment. The synchronized data is analyzed to extract objective metrics for suturing skill assessment.

Methods

The simulator has a camera positioned underneath the suturing membrane, enabling visual tracking of the needle during suturing. Needle tracking data enables extraction of meaningful metrics related to both the process and the product of the suturing task. To better simulate surgical conditions, the height of the system and the depth of the membrane are both adjustable. Metrics for assessment of suturing skill based on force/torque, motion, and physical contact are presented. Experimental data are presented from a study comparing attending surgeons and surgery residents.

Results

Analysis shows force metrics (absolute maximum force/torque in z-direction), motion metrics (yaw, pitch, roll), physical contact metric, and image-enabled force metrics (orthogonal and tangential forces) are found to be statistically significant in differentiating suturing skill between attendings and residents.

Conclusion and significance

The results suggest that this simulator and accompanying metrics could serve as a useful tool for assessing and teaching open surgery suturing skill.

Use of 3D Printing Technology to Create a Canine Simulator for Cerebrospinal Fluid Sampling at the Lumbar Subarachnoid Space

Cerebrospinal fluid (CSF) sampling at the lumbar subarachnoid space (LSS) is technically challenging to learn. Currently, training relies on cadaver availability or performance in a clinical scenario. This study aims to develop and validate a low-cost, high-fidelity simulator to train in this technique. Using three-dimensional printing technology, a model of a healthy adult dog's lumbosacral vertebral column was produced. The model was augmented with synthetic materials and a fluidic system to replicate all procedural steps and permit successful CSF collection. The simulator was validated by four experts, who rated it highly across multiple criteria. Final-year veterinary students were recruited to take part in practical sessions using either the simulator (n = 16) or a cadaver (n = 16). Performance was recorded for each student, and feedback was obtained using an anonymous online survey. Student performance was similar between groups (p = .2), with 87.5% and 68.75% of students in the simulator and cadaver group, respectively, successfully placing the needle into the LSS. All successful students in the simulator group were able to obtain a CSF sample, versus none in the cadaver group. No difference in the number of attempts was detected between groups (p > .99), with most students taking more than three attempts. User experience was similar between groups, with 93.8% of students in each group rating the session as a positive learning experience. In summary, we demonstrate the validity of a novel, low-cost, and anatomically precise simulator that can be used for teaching CSF sampling at the LSS.

A cadaveric perfused model with antegrade arteriovenous pulsatile circulation: a new tool for teaching endovascular skills

BACKGROUND

The benefits of using cadaveric humans in surgical training are well documented, and knowledge of the latest endovascular techniques is essential in the daily practice of vascular surgeons. Our study explores the feasibility of an affordable human cadaveric model with pulsatile and heated antegrade perfusion for reliable and reproducible endovascular or surgical simulation.

METHODS

We undertook cannulation of 7 human cadavers embalmed in a saturated salt solution to create a left-to-right central perfusion with a heated solution, from the ascending thoracic aorta to the right atrium. To that end, we used surgically created carotidojugular and femorofemoral arteriovenous fistulas. Biomedical engineers designed a prototype pump for pulsatile circulation. We monitored invasive blood pressure and temperature. We used this model for training for endovascular thoracic aortic procedures and open vascular surgeries.

RESULTS

The prototype pump achieved a pulsatile flow rate of 4.7 L/min. Effective cadaveric perfusion was achieved for several hours, not only with an arterioarterial pathway but also with arteriovenous circulation. The arterial pressures and in situ temperatures accurately restored vascular functions for life-like conditions. This new model made it possible to successfully perform thoracic endovascular aortic repair, subclavian artery stenting and simulation of abdominal open vascular trauma management. The saturated salt solution method and a specifically designed pump improved cost competitiveness.

CONCLUSION

Endovascular simulation on human cadavers, optimized with the pulsatile and heated perfusion system, can be a dynamic adjunct for surgical training and familiarization with new devices. This reproducible teaching tool could be relevant in all surgery programs.

Randomised controlled trial in cadavers investigating methods for intubation via a supraglottic airway device: Comparison of flexible airway scope guided versus a retrograde technique

OBJECTIVE

A supraglottic airway device (SAD) may be utilised for rescue re-oxygenation following a failed attempt at endotracheal intubation with direct or video laryngoscopy. However, the choice of subsequent method to secure a definitive airway is not clearly established. The aim of the present study was to compare two techniques for securing a definitive airway via the in-situ SAD.

METHODS

A randomised controlled trial was undertaken. The population studied was emergency physicians (EPs) attending a cadaveric airway course. The intervention was intubation through a SAD using a retrograde intubation technique (RIT). The comparison was intubation through a SAD guided by a flexible airway scope (FAS). The primary outcome was time to intubation. The trial was registered with ANZCTR.org.au (ACTRN12621000995875).

RESULTS

Four EPs completed intubations using both methods on four cadavers for a total of 32 experiments. The mean time to intubation was 18.2 s (standard deviation 8.8) in the FAS group compared with 52.9 s (standard deviation 11.7) in the RIT group; a difference of 34.7 s (95% confidence interval 27.1-42.3, P < 0.001). All intubations were completed within 2 min and there were no equipment failures or evidence of airway trauma.

CONCLUSION

Successful tracheal intubation of cadavers by EPs is achievable, without iatrogenic airway trauma, via a SAD using either a FAS or RIT, but was 35 s quicker with the FAS.

An Innovative Biological Model for Ultrasound-Guided Central Venous Access Simulation

INTRODUCTION

Simulation training is an increasingly used method to train medical students in the use of ultrasound guidance for vascular access positioning. Although very efficient for basic training, commercial simulators for vascular access do not reproduce real-life conditions. We developed a biological training model, using porcine liver, and compared it with an existing commercial model.

METHODS

Whole porcine livers were used by perfusing the portal vein system after inferior vena cava clamping. Thirty-three practitioners accustomed to ultrasound-guided procedure were enrolled to perform an ultrasound-guided vascular procedure on both biological and commercial models. Procedure duration was recorded and 10-point scales were used to compare the 2 models regarding image quality, procedure feeling, and similarity with the real-life procedure.

RESULTS

Participants reported a better image quality with the biological model (8.8 ± 1 vs. 7.7 ± 2, P = 0.007) as well as a significant difference in the procedure feeling (8.0 ± 1 vs. 6.9 ± 1.9, P = 0.002). Real-life likeness was significantly better for the biological model (8.4 ± 1.1 vs. 4.5 ± 6, P < 0.0001). Procedure duration was almost 3 times longer using the biological model than the commercial model (209.6 ± 189.0 vs. 59.8 ± 50.1, P < 0.0001).

CONCLUSIONS

This study validates our biological model of porcine's liver as an interesting training model, allowing closer real-life perception than its commercial counterpart. This model could complement and enhance simulation learning.

An in vitro assessment of light intensity provided during direct laryngeal visualization by videolaryngoscopes with Macintosh geometry blades

BACKGROUND

Adequate illumination of the larynx is needed during laryngoscopy to facilitate tracheal intubation. The International Organization for Standardization (ISO) has established a minimum light intensity for direct laryngoscopy (DL) of over 500 lux for at least ten minutes, but no such standard exists for Macintosh geometry videolaryngoscope (Mac-VL) blades, which allow for both direct or indirect (videoscopic) viewing of the larynx. Using in situ bench and in vitro testing in a human cadaver, we determined illumination and luminance values delivered by various Mac-VLs and compared these with published minimum lighting benchmarks as well as a reference direct laryngoscope.

METHODS

We tested six Mac-VLs (i-view™, McGRATH™ MAC, GlideScope® Spectrum™ [single-use] DVM S4, GlideScope® Titanium [reusable] Mac T4, C-MAC® S [single-use] Macintosh #4, C-MAC® [reusable] Macintosh #4) together with one direct laryngoscope (Heine LED). Each laryngoscope was assessed with three measurements, as follows: part 1: illuminance (lux) was measured in situ using a purpose-designed benchtop light intensity measurement apparatus; part 2: luminance (light reflected back to the eye) was measured (in candela m^-2 [cd·m^-2]) during videolaryngoscopy (VL) and DL in a human cadaver using a spot meter pointed at the interarytenoid notch; part 3: illuminance (lux) was measured during VL and DL in a human cadaver using a light meter surgically implanted just proximal to the vocal cords.

RESULTS

Illuminance and luminance varied significantly among the Mac-VLs. Mean (standard devitation) illuminance among the six tested Mac-VLs ranged from 117 (11) to 2,626 (42) lux in the measurement apparatus and from 228 (11) to 2,900 (374) lux by the surgically implanted light meter in the cadaver. All values were less than the reference Heine direct laryngoscope and some fell below the published ISO standard of 500 lux for DL. Luminance testing by spot meter had a similarly wide range, varying from 3.78 (0.60) to 49.1 (10.4) cd·m^-2, with some Mac-VLs delivering less luminance than the reference Heine direct laryngoscope.

CONCLUSIONS

Our results indicate that illuminance and luminance provided by Mac-VLs used for direct laryngeal viewing varies substantially between devices, with some falling below standards previously suggested as the minimum required for DL. While this may have no implications for the quality of image visible on a device's video monitor, the clinician should be aware that when Mac-VLs are used for direct viewing of the larynx, lighting may not be optimal. This might adversely affect ease or success of tracheal intubation.

Immersive Virtual Reality for Surgical Training: A Systematic Review

BACKGROUND

Immersive virtual reality (iVR) simulators provide accessible, low cost, realistic training adjuncts in time and financially constrained systems. With increasing evidence and utilization of this technology by training programs, clarity on the effect of global skill training should be provided. This systematic review examines the current literature on the effectiveness of iVR for surgical skills acquisition in medical students, residents, and staff surgeons.

METHODS

A literature search was performed on MEDLINE, EMBASE, CENTRAL, Web of Science and PsycInfo for primary studies published between January 1, 2000 and January 26, 2021. Two reviewers independently screened titles, abstracts, and full texts, extracted data, and assessed quality and strength of evidence using the Medical Education Research Quality Instrument (MERSQI) and Cochrane methodology. Results were qualitatively synthesized, and descriptive statistics were calculated.

RESULTS

The literature search yielded 9650 citations, with 17 articles included for qualitative synthesis. The mean (SD) MERSQI score was 11.7 (1.9) out of 18. In total, 307 participants completed training in four disciplines. Immersive VR-trained groups performed 18% to 43% faster on procedural time to completion compared to control (pooled standardized mean difference = -0.90 [95% CI=-1.33 to -047, I²=1%, P < 0.0001]). Immersive VR trainees also demonstrated greater post-intervention scores on procedural checklists and greater implant placement accuracy compared to control.

CONCLUSIONS

Immersive VR incorporation into surgical training programs is supported by high-quality, albeit heterogeneous, studies demonstrating improved procedural times, task completion, and accuracy, positive user ratings, and cost-effectiveness.

Developing a Novel, At-Home Procedure Curriculum for Fourth-Year Medical Students in Response to the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) pandemic provided our institution a unique opportunity to develop a new procedural curriculum for our fourth-year, emergency medicine-bound medical students. A significant portion of our ED’s fourth-year elective has traditionally been centered in our simulation center, using high-fidelity simulation models to practice important emergency medicine procedures. Due to the pandemic, the simulation center was unavailable for our use, and this new curriculum was created in an effort to fill this gap in procedural education.

Human Cadaveric Artificial Lung Tumor-Mimic Training Model

Introduction: An important phase in surgical training is gaining experience in real human anatomical situations. When a cadaver is available it may complement the various artificial practice models. However, it is often necessary to supplement the characteristics of the cadavers with a simulation of a tumor. Our objective was to develop an easy-to-create, realistic artificial tumor-mimic model for peripheral lung tumor resection practice.

Methods: In our work we injected barium sulphate enriched silicone suspension into 10 isolated, non-fixed lungs of human cadavers, through the puncture of the visceral pleura. Four lesions–apical, hilar and two peripheral–were created in each of ten specimens. After fixation CT scans were obtained and analyzed. The implanted tumor-mimics were examined after anatomical preparation and slicing. Also performed CT-guided percutaneous puncture was also performed to create the lesions in situ in two lungs of human cadavers.

Results: Analyzing the CT data of 10 isolated lungs, out of 40 lesions, 34 were nodular (85.0%) and in the nodular group five were spiculated (12.5%). Satellite lesions were formed in two cases (5.0%). Relevant outflow into vessels or airway occurred in five lesions (12.5%). Reaching the surface of the lung occured in 11 lesions (27.5%). The tumor-mimics were elastic and adhered well to the surrounding tissue. The two lesions, implanted via percutaneous puncture, both were nodular and one also showed lobulated features.

Conclusion: Our artificial tumor-mimics were easy to create, varied in shape and size, and with percutaneous implantation the lesions provide a model for teaching every step of a surgical procedure.

Teaching bone marrow procedures at pelvic and sternal sites: a high fidelity anatomy simulation

The bone marrow aspirate and biopsy procedure are fundamental to the diagnosis of many hematologic pathologies. We describe a hands-on, anatomy-based workshop that allows learners to practice bone marrow procedures on cadavers. Notably, participants learned how to perform sternal aspirates: a procedure rarely performed in real-life practice. Learners valued the experience and described increased comfort with the procedure after the workshop. This workshop provides a valuable opportunity for trainees to learn a procedural skill in a safe, high fidelity environment. Given its hands-on nature, residency training programs could also adapt it for direct observation and trainee assessment.

ICG Lymphography in a 4-week Postmortem Cadaver: Implications for a Supermicrosurgery Training Model

Surgical models are invaluable resources for training and for research and innovation. In the field of supermicrosurgery (SM), options for surgical models remain limited and imperfect. We report the use of a fresh, previously frozen 4-week postmortem cadaveric specimen for successful distal to proximal indocyanine green (ICG) lymphography of the upper extremity. Our technique was confirmed with handheld SPY fluorescence imaging, which visualized a clearly defined, linear lymphatic system. By outlining a straightforward, reproducible method of lymphatic mapping in cadaveric specimens, our group aims to expand the frontiers of surgical models for SM.

Influence of undergraduate medical education exposure to cadaveric dissection on choice of surgical specialty: a national survey of Canadian surgical residents

Background

The number of Canadian Residency Matching Service (CaRMS) applicants ranking surgical specialties as their first choice has declined over the past 20 years; concurrently, there has been a reduction in the number of hours spent teaching undergraduate medical education (UGME) anatomy, particularly with cadaveric dissection. The aim of this study was to determine the factors that most influence selection of a surgical specialty, with specific focus on the impact of UGME anatomy training.

Methods

A 36-item cross-sectional survey was designed by experts in medical education and distributed to all current surgical residents in Canada in October 2018. Responses were recorded on a 5-point Likert scale or by means of list ranking. We analyzed univariable outcomes with a t test for continuous outcomes and the χ² test for dichotomous outcomes.

Results

Of 1493 surgical residents, 228 responded to the survey (response rate 15.3%). Respondents reported experiences on core rotations and elective rotations, and access to a mentor as the most important factors in deciding to pursue a surgical residency. Anatomy training with or without cadaveric dissection was moderately influential in respondents’ first-choice CaRMS discipline (mean Likert scale score 2.97 [standard deviation (SD) 1.34] and 2.87 [SD 1.26], respectively). General surgery residents’ CaRMS applications were more likely to have been influenced by UGME anatomy training than the applications by residents in other surgical specialties (p < 0.001). The impact of UGME anatomy training did not vary between postgraduate years or between male and female residents.

Conclusion

Canadian surgical residents’ decision to apply to a surgical specialty did not seem to be strongly influenced by their UGME anatomy training, with or without cadaveric dissection, but, rather, by factors such as clinical experience and surgical mentorship. Further evaluation of groups that were more positively affected by their UGME anatomy training is warranted.

Taking care of life: the new Italian law on post-mortem donation for study purposes, training and scientific research

Anatomical dissection is considered a fundamental practice in the medical curriculum. Not only does it help students to familiarize themselves with the various bodily organs and to refine their surgical practice, it also fosters an attitude of awareness and respect towards death and the values of solidarity. On 10th February 2020, the Italian Parliament passed a new law entitled "Rules on the disposition of one's own body and post-mortem tissues for study purposes, training and scientific research". Here, we outline the main ethical and legal aspects of this law and suggest initiatives to encourage body donation. Through careful analysis of the law, we intend to open a discussion on the main ethical issues and to make comparisons with the international situation. The new legislation fills serious gaps in an area of great ethical relevance; not only does it endorse fundamental ethical principles, it also provides important guidelines for strengthening body donation, such as: ensuring respect for the dignity of the deceased, providing express consent, appointing a trustee, promoting information for both doctors and the community, and banning all forms of trade in bodies or body parts. This law is certainly an important milestone on the road to overcoming the scarcity of bodies for study and research. However, it is also essential to promote a favourable attitude to body donation and to strive to overcome obstacles to this practice by supporting continuous dialogue between anatomical institutes and the community. Further studies are necessary in order to assess the impact of the new law.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 2. Planning and implementing safe management of the patient with an anticipated difficult airway

PURPOSE

Since the last Canadian Airway Focus Group (CAFG) guidelines were published in 2013, the published airway management literature has expanded substantially. The CAFG therefore re-convened to examine this literature and update practice recommendations. This second of two articles addresses airway evaluation, decision-making, and safe implementation of an airway management strategy when difficulty is anticipated.

SOURCE

Canadian Airway Focus Group members, including anesthesia, emergency medicine, and critical care physicians were assigned topics to search. Searches were run in the Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL databases. Results were presented to the group and discussed during video conferences every two weeks from April 2018 to July 2020. These CAFG recommendations are based on the best available published evidence. Where high-quality evidence is lacking, statements are based on group consensus.

FINDINGS AND KEY RECOMMENDATIONS

Prior to airway management, a documented strategy should be formulated for every patient, based on airway evaluation. Bedside examination should seek predictors of difficulty with face-mask ventilation (FMV), tracheal intubation using video- or direct laryngoscopy (VL or DL), supraglottic airway use, as well as emergency front of neck airway access. Patient physiology and contextual issues should also be assessed. Predicted difficulty should prompt careful decision-making on how most safely to proceed with airway management. Awake tracheal intubation may provide an extra margin of safety when impossible VL or DL is predicted, when difficulty is predicted with more than one mode of airway management (e.g., tracheal intubation and FMV), or when predicted difficulty coincides with significant physiologic or contextual issues. If managing the patient after the induction of general anesthesia despite predicted difficulty, team briefing should include triggers for moving from one technique to the next, expert assistance should be sourced, and required equipment should be present. Unanticipated difficulty with airway management can always occur, so the airway manager should have a strategy for difficulty occurring in every patient, and the institution must make difficult airway equipment readily available. Tracheal extubation of the at-risk patient must also be carefully planned, including assessment of the patient's tolerance for withdrawal of airway support and whether re-intubation might be difficult.

Simulation training for emergency skills: effects on ICU fellows' performance and supervision levels

BACKGROUND

The application of manual emergency skills is essential in intensive care medicine. Simulation training on cadavers may be beneficial. The aim of this study was to analyze a skill-training aiming to enhance ICU-fellows´ performance.

METHODS

A skill-training was prepared for chest tube insertion, pericardiocentesis, and cricothyroidotomy. Supervision levels (SL) for entrustable professional activities (EPA) were applied to evaluate skill performance. Pre- and post-training, SL and fellows´ self- versus consultants´ external assessment was compared. Time on skill training was compared to conventional training in the ICU-setting.

RESULTS

Comparison of pre/post external assessment showed reduced required SL for chest tube insertion, pericardiocentesis, and cricothyroidotomy. Self- and external assessed SL did not significantly correlate for pre-training/post-training pericardiocentesis and post-training cricothyroidotomy. Correlations were observed for self- and external assessment SL for chest tube insertion and pre-assessment for cricothyroidotomy. Compared to conventional training in the ICU-setting, chest tube insertion training may further be time-saving.

CONCLUSIONS

Emergency skill training separated from a daily clinical ICU-setting appeared feasible and useful to enhance skill performance in ICU fellows and may reduce respective SL. We observed that in dedicated skill-training sessions, required time resources would be somewhat reduced compared to conventional training methods.

Comparison of Hands-On Versus Online Learning in Teaching Ultrasound Skills for Achilles Tendon Rupture: A Pilot Study

Introduction

In the emergency department, the diagnosis of an Achilles tendon rupture (ATR) is reportedly missed in greater than 20% of cases. A limited number of studies evaluate the use of cadaver models as a potential ultrasound teaching and training modality. We hypothesize that emergency medicine residents can effectively utilize point-of-care ultrasound (POCUS) on cadaver models and a focused teaching intervention to assess their ability to detect ATRs.

Methods

A prospective study of 23 EM residents was performed. All participants in the study were divided into two learner groups: (a) independent and (b) hands-on. The independent learner group received a 30-minute online didactic lecture demonstrating how to diagnose ATRs. The hands-on learner group received direct instruction on cadaver lower leg models with a ruptured and normal Achilles tendon (AT). Both groups then participated in identifying either normal or ruptured ATs on six cadaver lower leg models.

Results

The sensitivity and specificity were 89% and 82% in the independent learner group 96% and 100% in the hands-on learner group, respectively. The overall sensitivity and specificity were 91% and 88%, respectively. There was a trend toward successful identification with increased years of residency training.

Conclusions

In this study, lower leg and ankle cadaver models were found to be as effective as an independent learner model for potential POCUS teaching and training modality in both novice and more advanced trainees.

Development and Implementation of an Educational Simulation Workshop in Fiberoptic Laryngoscopy for Radiation Oncology Residents

PURPOSE

Fiberoptic laryngoscopy (FOL) is a critical tool for the diagnosis, staging, assessment of treatment response, and detection of recurrence for head and neck (H&N) malignancies. No standardized recommendations exist for procedural FOL education in radiation oncology. We therefore implemented a pilot simulation workshop to train radiation oncology residents in pertinent H&N anatomy and FOL technique.

METHODS AND MATERIALS

A 2-phase workshop and simulation session was designed. Residents initially received a lecture on H&N anatomy and the logistics of the FOL examination. Subsequently, residents had a practical session in which they performed FOL in 2 simulated environments: a computerized FOL program and mannequin-based practice. Site-specific attending physicians were present to provide real-time guidance and education. Pre- and postworkshop surveys were administered to the participants to determine the impact of the workshop. Subsequently, postgraduate year (PGY)-2 residents were required to complete 6 supervised FOL examinations in clinic and were provided immediate feedback.

RESULTS

Annual workshops were performed in 2017 to 2019. The survey completion rate was 14 of 18 (78%). Participants ranged from fourth-year medical students to PGY-2 to PGY-5 residents. All PGY-2 residents completed their 6 supervised FOL examinations. On a 5-point Likert scale, mean H&N anatomy knowledge increased from 2.4 to 3.7 (standard deviation = 0.6, P < .0001). Similarly, mean FOL procedural skill confidence increased from 2.2 to 3.3 (standard deviation = 0.7, P < .0001). These effects were limited to novice (fourth-year medical students to PGY-2) participants. All participants found the exercise clinically informative.

CONCLUSIONS

A simulation-based workshop for teaching FOL procedural skills increased confidence and procedural expertise of new radiation oncology residents and translated directly to supervised clinical encounters. Adoption of this type of program may help to improve resident training in H&N cancer.

Investigation of a three-dimensional printed dynamic cervical spine model for anatomy and physiology education

INTRODUCTION

Three-dimensional (3D) printing of anatomical structures is a growing method of education for students and medical trainees. These models are generally produced as static representations of gross surface anatomy. In order to create a model that provides educators with a tool for demonstration of kinematic and physiologic concepts in addition to surface anatomy, a high-resolution segmentation and 3D-printingtechnique was investigated for the creation of a dynamic educational model.

METHODS

An anonymized computed tomography scan of the cervical spine with a diagnosis of ossification of the posterior longitudinal ligament was acquired. Using a high-resolution thresholding technique, the individual facet and intervertebral spaces were separated, and models of the C3-7 vertebrae were 3D-printed. The models were placed on a myelography simulator and subjected to flexion and extension under fluoroscopy, and measurements of the spinal canal diameter were recorded and compared to in-vivo measurements. The flexible 3D-printed model was then compared to a static 3D-printed model to determine the educational benefit of demonstrating physiologic concepts.

RESULTS

The canal diameter changes on the flexible 3D-printed model accurately reflected in-vivo measurements during dynamic positioning. The flexible model also was also more successful in teaching the physiologic concepts of spinal canal changes during flexion and extension than the static 3D-printed model to a cohort of learners.

CONCLUSIONS

Dynamic 3D-printed models can provide educators with a cost-effective and novel educational tool for not just instruction of surface anatomy, but also physiologic concepts through 3D ex-vivo modeling of case-specific physiologic and pathologic conditions.

Investigation and Feasibility of Combined 3D Printed Thermoplastic Filament and Polymeric Foam to Simulate the Cortiocancellous Interface of Human Vertebrae

Disorders of the spine are among the most common indications for neurosurgical and orthopedic surgical interventions. Spinal fixation in the form of pedicle screw placement is a common form of instrumentation method in the lower cervical, thoracic, and lumbar spine. A vital principle to understand for the safe and accurate placement of pedicle screws is the palpable difference between the cortical and cancellous bone, both of which have different material properties and compositions. Probing and palpation of the hard cortical bone, also known as the “ventral lamina”, covering the neural elements of the spinal canal during screw placement provides manual feedback to the surgeon, indicating an impending breach if continued directional force is applied. Generally, this practice is learned at the expense of patients in live operating room scenarios. Currently, there is a paucity of human vertebra simulation designs that have been validated based on the in vivo ultrastructure and physical properties of human cortical and cancellous bone. In this study, we examined the feasibility of combining three-dimensionally printed thermoplastic polymers with polymeric foam to replicate both the vertebral corticocancellous interface and surface anatomy for procedural education.

Where do these cadavers come from?

Cadaveric surgical courses are highly useful in developing operative skills, however, the provenance of the cadavers themselves remains opaque. Trade in cadaveric parts is an important source of material for courses, and this has spawned the unique service of body brokerage. Body brokers, however, operate in an unregulated market and obtain bodies by exploiting family members' altruistic instincts and financial concerns. Unethical and illegal sale of body parts has been well-documented, while the use of cadavers for uses other than that consented by donors is also a key concern. Undoubtedly, cadaveric surgical courses would have used bodies sourced from brokers, and questions remain about the moral and ethical implications of this. We discuss this issue using an ethical and historical context as well as offering solutions to ensure the ethical sourcing of cadavers for surgical training.