Perfused fresh cadavers: method for application to surgical simulation

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.

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.

Simulation training of laparoscopic biliary-enteric anastomosis with a three-dimensional-printed model leads to better skill transfer: a randomized controlled trial

AIM

A new simulation model and training curriculum for laparoscopic bilioenteric anastomosis has been developed. Currently, this concept lacks evidence for the transfer of skills from simulation to clinical settings. This study was conducted to determine whether training with a three-dimensional (3D) bilioenteric anastomosis model result in greater transfer of skills than traditional training methods involving video observation and a general suture model.

METHODS

Fifteen general surgeons with no prior experience in laparoscopic biliary-enteric anastomosis were included in this study and randomised into three training groups: video observation only, practice using a general suture model, and practice using a 3D-printed biliary-enteric anastomosis model. Following five training sessions, each surgeon was asked to perform a laparoscopic biliary-enteric anastomosis procedure on an isolated swine organ model. The operative time and performance scores of the procedure were recorded and compared among the three training groups.

RESULTS

The operation time in the 3D-printed model group was significantly shorter than the suture and video observation groups ( P =0.040). Furthermore, the performance score of the 3D-printed model group was significantly higher than those of the suture and video observation groups ( P =0.001). Finally, the goal score for laparoscopic biliary-enteric anastomosis in the isolated swine organ model was significantly higher in the 3D model group than in the suture and video observation groups ( P =0.004).

CONCLUSIONS

The utilisation of a novel 3D-printed model for simulation training in laparoscopic biliary-enteric anastomosis facilitates improved skill acquisition and transferability to an animal setting compared with traditional training techniques.

Lessons Learned: Large-Scale Perfused Cadaver Training in Three Different Curricular Environments

BACKGROUND

Perfused cadavers are viable training models for operating room surgical skills, increasing fidelity of vascular anatomy, dissection, and tissue handling. In addition, perfused cadavers may have benefits in military medical training environments with a focus on hemorrhage control and vascular access.

OBJECTIVES

We created a large-scale training exercise with perfused cadavers in three different environments and aim to share the curricular design and feedback from the exercise.

METHODS

We conducted a 4-day simulation training exercise with 13 perfused cadavers in 3 different environments: hospital environment, the austere echelons of care environment, and a controlled-settings tent for hemorrhage control and needle decompression training. Through an anonymous online survey and an after-action review (AAR), we elicited feedback on advantages, disadvantages, costs, and comparison to models of porcine and fresh cadavers for procedures and existing courses.

RESULTS

A total of 324 participants were trained with 13 perfused cadavers for over 4 days from a variety of specialties and on different procedures and surgical skills. Based on 130 respondents to the survey and the AAR, perfused cadavers were rated to have realistic arterial bleeding and bleeding control training. In addition, perfused cadavers provided increased realism and fidelity for surgical skills. There were disadvantages of logistical requirements, cleanup, costs, and mobility.

CONCLUSION

Perfused cadavers can be implemented effectively for hemorrhage control training, surgical and procedure skills, and even exercises in austere environments, but require significant logistical and planning considerations. The training value is maximized with a progressive curriculum from hemorrhage control iterations to more invasive surgical procedures, such as thoracotomy and exploratory laparotomy.

Continuous Instrument Tracking in a Cerebral Corticectomy Ex Vivo Calf Brain Simulation Model: Face and Content Validation

BACKGROUND AND OBJECTIVES

Subpial corticectomy involving complete lesion resection while preserving pial membranes and avoiding injury to adjacent normal tissues is an essential bimanual task necessary for neurosurgical trainees to master. We sought to develop an ex vivo calf brain corticectomy simulation model with continuous assessment of surgical instrument movement during the simulation. A case series study of skilled participants was performed to assess face and content validity to gain insights into the utility of this training platform, along with determining if skilled and less skilled participants had statistical differences in validity assessment.

METHODS

An ex vivo calf brain simulation model was developed in which trainees performed a subpial corticectomy of three defined areas. A case series study assessed face and content validity of the model using 7-point Likert scale questionnaires.

RESULTS

Twelve skilled and 11 less skilled participants were included in this investigation. Overall median scores of 6.0 (range 4.0-6.0) for face validity and 6.0 (range 3.5-7.0) for content validity were determined on the 7-point Likert scale, with no statistical differences between skilled and less skilled groups identified.

CONCLUSION

A novel ex vivo calf brain simulator was developed to replicate the subpial resection procedure and demonstrated face and content validity.

A cost-effective model for training in Robot-Assisted Sacrocolpopexy

BACKGROUND

The number of robotically assisted sacrocolpopexy procedures are increasing; therefore, experienced clinicians are needed. Simulation-based cadaver models are challenging in aspects of cost and availability. Therefore, we need to look at alternative and more cost-effective models.

OBJECTIVE

The objective of this video was to design a new surgical model for the training of robotic-assisted sacrocolpopexy, which is affordable and accessible.

METHODS

We used a whole chicken model to simulate the female pelvic floor. We used Medtronic's Hugo™ RAS system as the robotic console in that procedure. A vaginal cuff was prepared from the proventriculus (stomach), and a Y shaped mesh was secured to the ischium to simulate the sacrocolpopexy procedure.

CONCLUSION

This model is easily constructed and in our view is cost-effective. We have demonstrated a new valuable education tool that can serve as a practical simulation model to teach the sacrocolpopexy procedure and to improve trainees' skills. A larger cohort study size is essential to demonstrate the learning curve among young trainees using this simulation model.

Assessment of a Perfusion and Ventilation Method for Detecting Lung and Liver Injury in a Cadaveric Model

Surgical simulation models have been developed using post-mortem human subjects (PMHS). These models involve the pressurization and ventilation of the PMHS to create a more realistic environment for training and the practice of surgical procedures. The overall objective of this study was to determine the feasibility of a previously developed surgical simulation model to detect soft tissue injuries during a ballistic impact to the torso. One of the main limitations of using PMHS for the assessment of soft tissue injuries in the field of injury biomechanics is the lack of physiological blood flow. To overcome this limitation, the assessment of the surgical simulation model for use in injury biomechanics applications was conducted based on data collected from behind armor blunt trauma (BABT) case studies. Documented injuries in real-world cases included anterior lung contusion, posterior lung contusion, and liver contusion. These real-world injuries were compared to those seen post-impact in the PMHS using pathological and histological techniques. Discussion of limitations and future work is presented.

Robotic Medtronic Hugo™ RAS System Is Now Reality: Introduction to a New Simulation Platform for Training Residents

The use of robotic surgery (RS) in urology has grown exponentially in the last decade, but RS training has lagged behind. The launch of new robotic platforms has paved the way for the creation of innovative robotics training systems. The aim of our study is to test the new training system from Hugo™ RAS System-Medtronic. Between July 2020 and September 2022, a total of 44 residents from urology, gynaecology and general surgery at our institution participated in advanced robotic simulation training using the Hugo™ RAS simulator. Information about sex, age, year of residency, hours spent playing video games, laparoscopic or robotic exposure and interest in robotics (90.9% declared an interest in robotics) was collected. The training program involved three robotic exercises, and the residents performed these exercises under the guidance of a robotics tutor. The residents' performance was assessed based on five parameters: timing, range of motion, panoramic view, conflict of instruments and exercise completion. Their performance was evaluated according to an objective Hugo system form and a subjective assessment by the tutor. After completing the training, the residents completed a Likert scale questionnaire to gauge their overall satisfaction. The rate of the residents' improvement in almost all parameters of the three exercises between the first and the last attempts was statistically significant (p < 0.02), indicating significant progress in the residents' robotic surgical skills during the training. The mean overall satisfaction score ± standard deviation (SD) was 9.4 ± 1.2, signifying a high level of satisfaction among the residents with the training program. In conclusion, these findings suggest that the training program utilizing the Hugo™ RAS System is effective in enhancing robotic surgical skills among residents and holds promise for the development of standardized robotics training programs in various surgical specialties.

Comparing the volume of vascular intersection of two femoral neck fracture fixation implants using an In silico technique

Femoral neck fracture displacement with subsequent vascular disruption is one of the factors that contribute to trauma-induced avascular necrosis of the femoral head. Iatrogenic damage of the intraosseous arterial system during fixation of femoral neck fracture is another possible cause of avascular necrosis that is less well understood. Recently, Zhao et al (2017) reconstructed 3D structures of intraosseous blood supply and identified the epiphyseal and inferior retinacular arterial system to be important structures for maintaining the femoral head blood supply after femoral neck fracture. The authors therefore recommended placing implants centrally to reduce iatrogenic vascular injuries. Our in vitro study compared the spatial footprint of a traditional dynamic hip screw with an antirotation screw versus a newly developed hip screw with an integrated antirotation screw on intraosseous vasculature.

Methods

Three dimensional (3D) µCT angiograms of 9 cadaveric proximal femora were produced. Three segmented volumes-porous or cancellous bone, filled or cortical bone, and intraosseous vasculature-were converted to surface files. 3D in silico models of the fixation systems were sized and implanted in silico without visibility of the vascular maps. The volume of vasculature that overlapped with the devices was determined. The ratio of the vascular intersection to the comparator device was calculated, and the mean ratio was determined. A paired design, noninferiority test was used to compare the devices.

Results

Results indicate both significant (P < 0.001) superiority and noninferiority of the hip screw with an integrated antirotation screw when compared with a dynamic hip screw and antirotation screw for the volume of vasculature that overlapped with each device in the femoral neck.

Conclusions

Combining established methods of vascular visualization with newer methods enables an implant's impact on vascular intersection to be assessed in silico. This methodology suggests that when used for femoral neck fracture management, the new device intersects fewer blood vessels than the comparator. Comparative clinical studies are needed to investigate whether these findings correlate with the incidence of avascular necrosis and clinical outcomes.

Endoscopic neuroanatomy study using embalmed cadavers

Objectives

A firm understanding of anatomy is foundational for all medical students and residents. As opportunities for cadaveric study dwindle, we propose a simplified perfusion model for formalin fixed cadavers that allow for endoscopic neuroanatomical study and procedural practice. This model is easily accessible, cost effective, and valuable in medical training.

Materials and Methods

Cadavers were fixed through accepted methods that included formalin injection into the cranial vault. The perfusion system was set up using a series of catheters, tubing, and pressurized saline bag that forced saline into the various neuroanatomical spaces chosen for study.

Results

A neuroendoscope was subsequently introduced to explore and identify relevant neuroanatomical structures as well as to perform a 3rd ventriculostomy and filum sectioning.

Conclusion

Using formalin fixed cadavers for neuroendoscopic studies and procedural practice is a cost effective, multipurpose tool that can provide medical trainees with a strong understanding of anatomy as well as procedural practice.

Morphodynamic study of the corona mortis using the SimLife® technology

PURPOSE

Open book pelvic ring fractures are potentially life-threatening, due to their instability and major hemorrhage risk. During the open reduction and internal fixation, the pelvic approach remains a technical challenge, as the surgeon wants to prevent any iatrogenic damage of the vascular loop located in the retro-pubic area called corona mortis (CMOR). Recently, the cadaver perfused SimLife^® technology has been developed to improve the surgeon training, out of the operating room. This study aimed to compare two models of cadaveric dissection, to assess the interest of the perfused SimLife^® in providing dynamic aspect of anatomy in the identification of CMOR and its topography.

METHODS

Twelve human cadaveric pelvises have been dissected, following two protocols. 12 hemi-pelvises of the dissections were performed without perfusion (Model A), whereas the 12 other hemi-pelvises have been prepared with the SimLife^® pulsatile perfusion (Model B). The prevalence and morphologic parameters determined: length, diameter and distance between the CMOR and the pubic symphysis.

RESULTS

The CMOR has been found in 66.67% of the cases. The length, the diameter, and the distance between the CMOR and the pubic symphysis were significantly higher in model B (respectively p = 0.029, p = 0.01, and p = 0.022).

CONCLUSION

These results suggest that the CMOR is easier to identify and to dissect with the SimLife^® perfusion. As part of the surgical training of any trauma surgeon, this model could help him to keep in mind the CMOR topography, to improve the open book lesion management.

Development of a post-mortem human specimen flow model for advanced bleeding control training

INTRODUCTION

Prompt and effective hemorrhage control is paramount to improve survival in patients with catastrophic bleeding. In the ever-expanding field of bleeding control techniques, there is a need for a realistic training model to practice these life-saving skills. This study aimed to create a realistic perfused post-mortem human specimen (PMHS) flow model that is suitable for training various bleeding control techniques.

MATERIALS AND METHODS

This laboratory study was conducted in the SkillsLab & Simulation Center of Erasmus MC, University Medical Center Rotterdam, the Netherlands. One fresh frozen and five AnubiFiX® embalmed PMHS were used for the development of the model. Subsequent improvements in the exact preparation and design of the flow model were made based on model performance and challenges that occurred during this study and are described.

RESULTS

Circulating arteriovenous flow with hypertonic saline was established throughout the entire body via inflow and outflow cannulas in the carotid artery and jugular vein of embalmed PMHS. We observed full circulation and major hemorrhage could be mimicked. Effective bleeding control was achieved by placing a resuscitative endovascular balloon occlusion of the aorta (REBOA) catheter in the model. Regional perfusion significantly reduced the development of tissue edema.

CONCLUSION

Our perfused PMHS model with circulating arterial and venous flow appears to be a feasible method for the training of multiple bleeding control techniques. Regional arteriovenous flow successfully reduces tissue edema and increases the durability of the model. Further research should focus on reducing edema and enhancing the durability of the model.

Efficacy of a perfused cadaver model for simulated trauma resuscitation in advanced surgical skills training

Background

To develop a perfused cadaveric model for trauma surgery simulation, and to evaluate its efficacy in trauma resuscitation advanced surgical skills training.

Methods

Fourteen fourth-year general surgery residents attended this workshop at Siriraj Hospital (Bangkok, Thailand). Inflow and outflow cannulae and a cardiopulmonary bypass pump were used to create the perfusion circuit. Inflow was achieved by cannulating the right common carotid artery, and outflow by cannulation of both the right common femoral artery and the internal jugular vein. Arterial line monitoring was used to monitor resuscitation response and to control perfusion pressure. The perfusion solution comprised saline solution mixed 1:1 with glycerol (50%) and water with red food dye added. Advanced surgical skills during life-threatening injuries and damage control resuscitation operations were practiced starting from the airway to the neck, chest, peripheral vessels, abdomen, and pelvis. Resuscitative endovascular balloon occlusion of the aorta (REBOA) was also practiced. Post-workshop survey questions were grouped into three categories, including comparison with previous training methods; the realism of anatomical correlation and procedures; and, satisfaction, safety, and confidence. All questions and tasks were discussed among all members of the development team, and were agreed upon by at least 90% of experts from each participating medical specialty/subspecialty.

Results

The results of the three main groups of post-workshop survey questions are, as follows: (1) How the training compared with previous surgical training methods—mean score: 4.26/5.00, high score: 4.73/5.00; (2) Realism of anatomical correlation and procedures—mean score: 4.03/5.00, high score: 4.60/5.00; and, (3) Satisfaction, safety, and confidence—mean score: 4.24/5.00, high score: 4.47/5.00.

Conclusion

The developed perfused cadaveric model demonstrated potential advantages over previously employed conventional surgical training techniques for teaching vascular surgery at our center as evidenced by the improvement in the satisfaction scores from students attending perfused cadaveric training compared to the scores reported by students who attended earlier training sessions that employed other training techniques. Areas of improvement included ‘a more realistic training experience’ and ‘improved facilitation of decision-making and damage control practice during trauma surgery’.

The use of a surgical boot camp combining anatomical education and surgical simulation for internship preparedness among senior medical students

BACKGROUND

Senior medical students feel unprepared for surgical procedures and care for surgery patients when they begin their internship. This study sought to introduce and evaluate a surgical boot camp training for senior medical students.

METHODS

A 44-h surgical boot camp program of lectures on clinical practice simulation, anatomical dissections, and simulated operation on cadavers was designed, implemented, and evaluated during the 2018 to 2019 academic year. A self-administered questionnaire was used to assess students' perceptions of the content, delivery, and self-confidence. The mini-Clinical Evaluation Exercise (mini-CEX) and the Operative Performance Rating System were used to assess skills essential to good clinical care and to facilitate feedback.

RESULTS

Over 93% of the students were satisfied with the surgical boot camp, training equipment, and learning materials provided. After six sessions of training, 85.3% reported gaining self-confidence and performed better in some surgical procedures such as major gastrectomy. The mini-CEX scores suggested significant improvement in the students' clinical skills, attitudes, and behaviors (P < 0.01). Ninety-eight percent of students felt that the anatomical knowledge taught met their needs. The scores of the Operative Performance Rating System suggested that the students' surgical skills such as instruments handling, incising, treatment of surrounding tissues (blood vessels, nerves), and smoothness of the whole operation had increased significantly following the surgical boot camp (All P < 0.01).

CONCLUSION

The surgical boot camp curriculum improved students' satisfaction and confidence in core clinical practice competencies. Therefore, medical schools the world over should continue to seek ways to bridge the gaps between pre-clinical, clinical, and internship training.

Updates on cadaver surgical training in Japan: a systematic facility at Chiba University

Cadaver surgical training (CST), which ensures medical safety by improving the skills of surgeons, is popular overseas. However, training involves ethical issues given the use of cadavers. In 2012, the Japan Surgical Society and the Japanese Association of Anatomists compiled and opened the “Guidelines for Cadaver Dissection in Education and Research of Clinical Medicine (Guideline 2012)” to the public. This has allowed Japan to conduct CST or research under the regulations of Postmortem Examination and Corpse Preservation Act and the Body Donation Act. However, its dissemination has been sluggish. The Clinical Anatomy Lab (CAL), established in 2010 at Chiba University, is a facility for conducting CST and research. In the 11 years since its inception, 250 programs have been implemented. Orthopedics had the most implemented in the clinical field, with 120 (48%), followed by emergency and critical care medicine with 27 (10.8%), and neurological surgery with 27 (10. 8%). Based on the purpose of the training, the most common objective for the programs (approximately 83%) was education. Further, the highest number of programs was recorded in 2018 (34) and participants in 2017 (631). The implementation of CST requires more than just guiding surgeons to a dissection practice room. There are several methods of preserving cadavers to make them suitable for CST. For various surgical simulations, an operating table is more suitable than a dissection table. The current paper provides information on how to implement CST in universities that have so far only worked on anatomy education for medical students.

Validation of standardized training system for robot-assisted radical prostatectomy: comparison of perioperative and surgical outcomes between experienced surgeons and novice surgeons at a low-volume institute in Japan

INTRODUCTION

Although robot-assisted radical prostatectomy (RARP) has become a standard treatment modality in patients with prostate cancer (PCa), RARP is a complicated and difficult surgical procedure due to the risk of serious surgery-related complications. This study aimed to evaluate the validation of a standardized training system for RARP in patients with PCa at a single institute.

MATERIAL AND METHODS

We retrospectively reviewed the clinical and pathological records of 155 patients with PCa who underwent RARP at Gifu University between August 2018 and April 2021. We developed an institutional program for new surgeons based on the separation of the RARP procedure into six checkpoints. The primary endpoints were surgical outcomes and perioperative complications among three groups (expert, trainer, and novice surgeon groups).

RESULTS

The console time was significantly longer in the novice surgeon group than in the other groups. Regarding bladder neck dissection, ligation of lateral pedicles, and vesicourethral anastomosis, the operative time was significantly shorter in the expert group than in the other groups. Surgery-related complications occurred in 15 patients (9.7%).

CONCLUSIONS

Our training system for RARP might help reduce the influence of the learning curve on surgical outcomes and ensure that the surgeries performed at low-volume institutions are safe and effective.

Latex-injected, non-decapitated, saturated salt method-embalmed cadaver technique development and application as a head and neck surgery training model

Published cerebrovascular injection techniques have mostly used decapitated, fresh cadavers or heads embalmed with 10% formaldehyde. There have been no reports using vascular-injected cadavers for head and neck surgical training models or using vascular injections in saturated salt method-embalmed cadavers. Thus, we performed vascular labeling of five saturated salt method-embalmed cadavers without decapitation. Latex mixed with red ink was injected into the common carotid artery via a 3D-printed vascular adapter. The injection force was provided by a peristaltic pump. Thyroidectomy, submandibular gland excision, neck dissection, parotidectomy, and mandibulotomy were performed on both sides of each cadaver (n = 10). The consistency of the cadavers was softer than fresh ones. Subcutaneous tissues were well preserved, and muscles were moist and elastic. Five physicians graded the resemblance of the heads and necks of the latex-injected, saturated salt method-embalmed, non-decapitated of five cadavers compared to living humans using a Likert scale from 0 (no resemblance) to 5 (maximum resemblance). Fifty-two percent of the head and neck region resemblance scale ratings were four or five. Although the cadavers were practical for head and neck surgical simulations, the brain parenchyma was only partially preserved and unsuitable for use. The most distal arterial branches reached by the injected latex were measured. The external caliber of the smallest vessels reached were lacrimal arteries (mean caliber ± SD, 0.04 ± 0.04 mm; 95% CI [0, 0.09]). There were no significant differences in the mean caliber of the smallest vessels reached between the left- and right-sided arterial branches (all p < 0.05).

Evaluation of a 3D-Printed Transoral Robotic Surgery Simulator Utilizing Artificial Tissue

OBJECTIVES/HYPOTHESIS

Transoral robotic surgery (TORS) poses challenges for operators in training, with limited robot access on a platform requiring distinct surgical skills. Few simulators exist, and current virtual reality training modules exclude head and neck simulations. This study evaluates the construct validity for a novel low-cost TORS simulator.

STUDY DESIGN

Single institution prospective observational study.

METHODS

Using 3D-printed oral cavity structures and replaceable artificial tissue components, a modular TORS simulator was constructed for short-duration hands-on simulations with the da Vinci SI robot. Sixteen surgeons of differing robotic skill levels, no experience (novice), prior experience, and formal robot training, participated in simulated tonsil and tongue base tumor resections. Video recordings of each participant were graded by a blinded robotically trained surgeon using a 35-point Global Evaluative Assessment of Robotic Surgery (GEARS) criterion adapted for the TORS simulator.

RESULTS

Operators reporting formal robotic training or prior robot experience achieved significantly higher mean total GEARS scores compared to novice operators (32 vs. 20.5; P < .001). Overall, mean total GEARS scores correlated with reported experience level; novice operators scored 54% of total points at 19 (4.5), operators with prior experience scored 82.3% of total points at 28.8 (2.6), and robotically trained operators scored 97.1% of total points at 34 (1.7).

CONCLUSION

With a GEARS criterion, our simulator successfully differentiated novice from experienced and robotically trained operators of the da Vinci SI robot during simulated tonsillectomy and base of tongue resections. These findings support the construct validity of this prototype simulator and offer a foundation for further testing of predictive validity.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

The PASS Course: Practical Anatomy and Surgical Skills Course as a Pragmatic Primer for Senior Medical Students Pursuing Surgical Residency

The senior year of undergraduate medical education has been scrutinized for lacking emphasis from educators and value for students. Surgical residency program directors and medical students have reported different sets of perceived weaknesses as surgical trainees enter residency. With this in mind, we developed a novel rotation for senior medical students pursuing surgical residency. The rotation incorporates practical didactics, robust skill and simulation training, and an enriching anatomy experience that entails dissections and operations on embalmed and fresh tissue cadavers. To our knowledge, this is the first reported formal training experience for medical students that involves working with fresh tissue cadavers, which have been described as effective models for live human tissue in the operating room. We describe our multifaceted curriculum in detail, discuss its organization, and elaborate on its potential value. We also provide detailed explanations of the curriculum components so that other surgical educators may consider adopting them.

The utilization of perfused cadaver simulation in urologic training: a pilot study

Background

We sought to determine if participating in a surgical training session using perfused fresh human cadavers (PFHC) had a positive effect on urology residents’ confidence in performing open and endoscopic procedures.

Methods

Urology residents at our institution participated in a surgical training session in the West Virginia University Fresh Tissue Training Program, which utilized fresh cadavers with vascular perfusion. The session consisted of performing different urologic procedures (open and endoscopic) on the perfused fresh human cadavers (PFHC). Residents were given a survey to rate their confidence in different urologic procedures before, after, and 6 months after the session. Each procedure on the survey had 3–6 questions associated with it, with scores ranging from 0 (no confidence) to 4 (great confidence). Scores for each procedure before and after the session were compared.

Results

Six residents participated in the session. There was an increase in the score for every procedure performed after the session. Scores at 6 month follow up remained higher than the pre-session scores.

Conclusion

PFHCs offer an excellent opportunity to teach a wide variety of urologic procedures to residents. Incorporation of PFHCs may be very useful in urologic training, and further studies on its use are warranted.

A review of simulation training and new 3D computer-generated synthetic organs for robotic surgery education

We conducted a comprehensive review of surgical simulation models used in robotic surgery education. We present an assessment of the validity and cost-effectiveness of virtual and augmented reality simulation, animal, cadaver and synthetic organ models. Face, content, construct, concurrent and predictive validity criteria were applied to each simulation model. There are six major commercial simulation machines available for robot-assisted surgery. The validity of virtual reality (VR) simulation curricula for psychomotor assessment and skill acquisition for the early phase of robotic surgery training has been demonstrated. The widespread adoption of VR simulation has been limited by the high cost of these machines. Live animal and cadavers have been the accepted standard for robotic surgical simulation since it began in the early 2000s. Our review found that there is a lack of evidence in the literature to support the use of animal and cadaver for robotic surgery training. The effectiveness of these models as a training tool is limited by logistical, ethical, financial and infection control issues. The latest evolution in synthetic organ model training for robotic surgery has been driven by new 3D-printing technology. Validated and cost-effective high-fidelity procedural models exist for robotic surgery training in urology. The development of synthetic models for the other specialties is not as mature. Expansion into multiple surgical disciplines and the widespread adoption of synthetic organ models for robotic simulation training will require the ability to engineer scalability for mass production. This would enable a transition in robotic surgical education where digital and synthetic organ models could be used in place of live animals and cadaver training to achieve robotic surgery competency.

A systematic review of virtual reality for the assessment of technical skills in neurosurgery

OBJECTIVE

Virtual reality (VR) and augmented reality (AR) systems are increasingly available to neurosurgeons. These systems may provide opportunities for technical rehearsal and assessments of surgeon performance. The assessment of neurosurgeon skill in VR and AR environments and the validity of VR and AR feedback has not been systematically reviewed.

METHODS

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted through MEDLINE and PubMed. Studies published in English between January 1990 and February 2021 describing the use of VR or AR to quantify surgical technical performance of neurosurgeons without the use of human raters were included. The types and categories of automated performance metrics (APMs) from each of these studies were recorded.

RESULTS

Thirty-three VR studies were included in the review; no AR studies met inclusion criteria. VR APMs were categorized as either distance to target, force, kinematics, time, blood loss, or volume of resection. Distance and time were the most well-studied APM domains, although all domains were effective at differentiating surgeon experience levels. Distance was successfully used to track improvements with practice. Examining volume of resection demonstrated that attending surgeons removed less simulated tumor but preserved more normal tissue than trainees. More recently, APMs have been used in machine learning algorithms to predict level of training with a high degree of accuracy. Key limitations to enhanced-reality systems include limited AR usage for automated surgical assessment and lack of external and longitudinal validation of VR systems.

CONCLUSIONS

VR has been used to assess surgeon performance across a wide spectrum of domains. The VR environment can be used to quantify surgeon performance, assess surgeon proficiency, and track training progression. AR systems have not yet been used to provide metrics for surgeon performance assessment despite potential for intraoperative integration. VR-based APMs may be especially useful for metrics that are difficult to assess intraoperatively, including blood loss and extent of resection.

Surgical anatomy of the axillary artery: clinical implications for open shoulder surgery

BACKGROUND

Axillary artery injury is a devastating complication related to anterior shoulder surgery and can result in significant morbidity and/or mortality. The purpose of our study was to evaluate the course of the axillary artery in relation to bony landmarks of the shoulder and identify variations in artery position with humeral external rotation.

MATERIALS AND METHODS

Dissection of 18 shoulders (9 fresh whole-body cadavers) with simulated vessel perfusion using radiopaque dye was performed. The axillary artery position was measured from multiple points including 2 points on the coracoid base (C1 and C2), 3 points on the coracoid tip (C3-C5), 4 points on the glenoid: superior, middle, and inferior glenoid (D1-D4), and 2 points on the lesser tuberosity (L1 and L2). Fluoroscopic measurements were taken and compared at 0° and 90° of external rotation (F1 vs. F1' and F2 vs. F2'). Manual and fluoroscopic measurements were compared with one another using Kendall's τ_b correlation.

RESULTS

There were 6 male and 3 female cadavers with an average age of 67.2 ± 9.3 years (range: 49-77 years). The mean distance from the axillary artery to the coracoid base (C1 and C2) measured 21.1 ± 7.3 and 22.3 ± 7.4 mm, respectively, whereas the mean distance to the coracoid tip (C3, C4, and C5) measured 30.7 ± 9.3, 52.1 ± 20.2, and 46.5 ± 14.3 mm, respectively. Measurements relative to the glenoid face (D1, D2, and D3) showed a progressive decrease in mean distance from superior to inferior, measuring 31.6 ± 10.3, 16.5 ± 7.5, and 10.3 ± 7.3 mm, respectively, whereas D4 (inferior glenoid to axillary artery) measured 17.8 ± 10.7 mm. The minimum distance from the axillary artery to any point on the glenoid was as close as 4.1 mm (D3). There was a statistically significant difference in F1 (0° external rotation) vs. F1' (90° external rotation) (18.5 vs. 13.4 mm, P = .03). Kendall's τ_b correlation showed a strong, positive correlation between manual and fluoroscopic measurements (D4: 16.0 ± 12.5 mm vs. F1: 18.5 ± 10.7 mm) (τ_b = 0.556, P = .037).

CONCLUSION

The axillary artery travels an average of 1-1.8 cm from the inferior glenoid margin, which puts the artery at significant risk. In addition, the artery is significantly closer to the inferior glenoid with humeral external rotation. Surgeons performing anterior shoulder surgery should have a thorough understanding of the axillary artery course and understand changes in the position of the artery with external rotation of the humerus.

Evaluation of the efficacy of commercial and noncommercial tourniquets for extremity hemorrhage control in a perfused cadaver model

BACKGROUND

Tourniquets are a critical tool in the immediate response to life-threatening extremity hemorrhage; however, the optimal tourniquet type and effectiveness of noncommercial devices remain unclear. Our aim was to evaluate the efficacy of five tourniquets in a perfused-cadaver model.

METHODS

This prospective study used a perfused-cadaver model with standardized superficial femoral artery injury bleeding at 700 mL/min. Five tourniquets were tested: combat application tourniquet; rapid application tourniquet system; Stretch, Wrap, And Tuck Tourniquet; an improvised triangle bandage windlass; and a leather belt. Forty-eight medical students underwent a practical hands-on demonstration of each tourniquet. Using a random number generator, they placed the tourniquets on the bleeding cadaver in random order. Time to hemostasis, time to secure devices, estimated blood loss, and difficulty rating were assessed. A one-way repeated measures analysis of variance was used to compare efficacy between the tourniquets in achieving the outcomes.

RESULTS

The mean ± SD participant age was 25 ± 2.6 years, and 29 (60%) were male. All but one tourniquet was able to stop bleeding, but the rapid application tourniquet system had a 4% failure rate. Time to hemostasis and estimated blood loss did not differ significantly (p > 0.05). Stretch, Wrap, And Tuck Tourniquet required the longest time to be secured (47.8 ± 17.0 seconds), whereas the belt was the fastest (15.2 ± 6.5 seconds; p < 0.001). The improvised windlass was rated easiest to learn and apply, with 22 participants (46%) assigning a score of 1.

CONCLUSION

Four of five tourniquets evaluated, including both noncommercial devices, effectively achieved hemostasis. A standard leather belt was the fastest to place and was able to stop the bleeding. However, it required continuous pressure to maintain hemostasis. The improvised windlass was as effective as the commercial devices and was the easiest to apply. In an emergency setting where commercial devices are not available, improvised tourniquets may be an effective bridge to definitive care.

Brief report on combat trauma surgical training using a perfused cadaver model

BACKGROUND

Surgical combat casualty care presents difficult training challenges. Although several high-fidelity simulation (SIM) techniques have emerged, none are able to fully integrate the many intricacies involved in the care of a complex trauma patient. Herein, we report the use of perfused fresh human cadaver model for training and assessment of forward surgical teams (FSTs).

METHODS

Forward surgical teams attend a 4-day combat trauma surgical skills course including focused on trauma exposures. A half-day SIM involves the entire surgical team in four sequential surgical scenarios that involve the neck, chest, abdomen, and extremities, as well as airway management and resuscitation. Teams undergo immediate debriefing and videotape review of team dynamics and technical skills, as well as times to completion of critical interventions.

RESULTS

The data evaluated include five initial demonstration courses in which training metrics were available. Each team included both a junior and experienced surgeon, anesthesiologists, and surgical scrub technicians. As FSTs progressed through SIMs, they demonstrated improvements in team dynamics and technical skills evaluations. There was considerable variability in the times to completion of critical intervention, particularly for control of cardiac and vascular injuries.

CONCLUSION

Initial evaluations support the use of this novel perfused cadaver model for the training and evaluation of military FSTs. Preliminary data highlight the utility for open vascular, thoracic, and other high-acuity/low-volume procedures critical to combat casualty care. Larger studies are needed for model optimization and further validation of an objective structured technical assessment tool.

LEVEL OF EVIDENCE

Care management, level V.

Feasibility of fresh frozen human cadavers as a research and training model for endovascular image guided interventions

Objective

To describe the feasibility of a fresh frozen human cadaver model for research and training of endovascular image guided procedures in the aorta and lower extremity.

Methods

The cadaver model was constructed in fresh frozen human cadaver torsos and lower extremities. Endovascular access was acquired by inserting a sheath in the femoral artery. The arterial segment of the specimen was restricted by ligation of collateral arteries and, in the torsos, clamping of the contralateral femoral artery and balloon occlusion of the supratruncal aorta. Tap water was administered through the sheath to create sufficient intraluminal pressure to manipulate devices and acquire digital subtraction angiography (DSA). Endovascular cannulation tasks of the visceral arteries (torso) or the peripheral arteries (lower extremities) were performed to assess the vascular patency of the model. Feasibility of this model is based on our institute’s experiences throughout the use of six fresh frozen human cadaver torsos and 22 lower extremities.

Results

Endovascular simulation in the aortic and peripheral vasculature was achieved using this human cadaver model. Acquisition of DSA images was feasible in both the torsos and the lower extremities. Approximately 84 of the 90 target vessels (93.3%) were patent, the remaining six vessels showed signs of calcified steno-occlusive disease.

Conclusions

Fresh frozen human cadavers provide a feasible simulation model for aortic and peripheral endovascular interventions, and can potentially reduce the need for animal experimentation. This model is suitable for the evaluation of new endovascular devices and techniques or to master endovascular skills.

Multi-institutional validation of a perfused robot-assisted partial nephrectomy procedural simulation platform utilizing clinically relevant objective metrics of simulators (CROMS)

OBJECTIVE

To conduct a multi-institutional validation of a high-fidelity, perfused, inanimate, simulation platform for robot-assisted partial nephrectomy (RAPN) using incorporated clinically relevant objective metrics of simulation (CROMS), applying modern validity standards.

MATERIALS AND METHODS

Using a combination of three-dimensional (3D) printing and hydrogel casting, a RAPN model was developed from the computed tomography scan of a patient with a 4.2-cm, upper-pole renal tumour (RENAL nephrometry score 7×). 3D-printed casts designed from the patient's imaging were used to fabricate and register hydrogel (polyvinyl alcohol) components of the kidney, including the vascular and pelvicalyceal systems. After mechanical and anatomical verification of the kidney phantom, it was surrounded by other relevant hydrogel organs and placed in a laparoscopic trainer. Twenty-seven novice and 16 expert urologists, categorized according to caseload, from five academic institutions completed the simulation.

RESULTS

Clinically relevant objective metrics of simulators, operative complications, and objective performance ratings (Global Evaluative Assessment of Robotic Skills [GEARS]) were compared between groups using Wilcoxon rank-sum (continuous variables) and parametric chi-squared (categorical variables) tests. Pearson and point-biserial correlation coefficients were used to correlate GEARS scores to each CROMS variable. Post-simulation questionnaires were used to obtain subjective supplementation of realism ratings and training effectiveness.

RESULTS

Expert ratings demonstrated the model's superiority to other procedural simulations in replicating procedural steps, bleeding, tissue texture and appearance. A significant difference between groups was demonstrated in CROMS [console time (P < 0.001), warm ischaemia time (P < 0.001), estimated blood loss (P < 0.001)] and GEARS (P < 0.001). Six major intra-operative complications occurred only in novice simulations. GEARS scores highly correlated with the CROMS.

CONCLUSIONS

This perfused, procedural model offers an unprecedented realistic simulation platform, which incorporates objective, clinically relevant and procedure-specific performance metrics.

Design, Development, and Validation of a High-Fidelity “Ganglion Cyst” Model for Cadaveric Hand Surgery Training

Introduction This study presents a design and developmental model with prospective validation. This study was aimed to design, develop, and validate a cadaveric model simulator of a ganglion cyst to train surgeons in its surgical excision.

Materials and Methods A novel “ganglion cyst” was designed using a latex powder-free glove and water-based, water-soluble lubricant (K-Y jelly). This “ganglion cyst” was then inserted subcutaneously into a cadaveric hand, positioned over the dorsum of the wrist to simulate a ganglion lesion. This simulation model was prospectively validated using postsimulation surveys conducted on novices and experts in hand surgery. The simulation was conducted during a basic hand surgery cadaveric workshop that included a practical station on ganglion excision.

Results Both the novices and experts had a concurrent agreement that the simulator provided relevance, realism, and value as a simulator for the teaching, excision and procedural assessment of ganglions in the hand.

Conclusion The role of high-fidelity simulation has been documented in the literature for surgical procedures. This simple and affordable model that we have developed and validated allows for the creation of a high-fidelity ganglion simulator in the cadaveric hand for teaching, excision, and procedural assessment among trainees.

How Does Cadaveric Simulation Influence Learning in Orthopedic Residents?

OBJECTIVE

The objectives of this study were to understand how cadaveric simulation impacts learning in orthopedic residents, why it is a useful training tool, and how skills learnt in the simulated environment translate into the workplace.

DESIGN

This is a qualitative research study using in-depth, semistructured interviews with orthopedic residents who underwent an intensive cadaveric simulation training course.

SETTING

The study was conducted at the University Hospital Coventry & Warwickshire, a tertiary care center with integrated cadaveric training laboratory in England, United Kingdom.

PARTICIPANTS

Orthopedic surgery residents in the intervention group of a randomized controlled trial comparing intensive cadaveric simulation training with standard "on the job" training were invited to participate. Eleven of 14 eligible residents were interviewed (PGY 3-6, 8 male and 3 female).

RESULTS

Learning from cadaveric simulation can be broadly categorized into intrinsic, surgeon-driven factors, and extrinsic environmental factors. Intrinsic factors include participant ability to "buy-in" to the simulation exercise, willingness to push one's own learning boundaries in a "safe space" and take out on resident experience and self-reported confidence, with the greatest learning gains seen at around the PGY4 stage in individuals who reported low preintervention operative confidence. Extrinsic factors included; the opportunity to perform operations in their entirety without external pressures or attending "take-over," leading to subjective improvement in participant operative fluency and confidence. The intensive supervision of subspecialist attending surgeons giving real-time performance feedback, tips and tricks, and the opportunity to practice unusual approaches was highly valued by participants, as was paired learning with alternating roles as primary surgeon/assistant and multidisciplinary involvement of scrub-staff and radiographers. Cadaveric simulation added educational value beyond that obtained in low-fidelity simulation training by "stirring into practice" and "becoming through doing." In providing ultrarealistic representation of the space, ritualism, and costuming of the operating theater, cadaveric simulation training also enabled the development of a range of nontechnical skills and sociocultural "nontechnical" lessons of surgery.

CONCLUSIONS

Cadaveric simulation enhances learning in both technical and nontechnical skills in junior orthopedic residents within a single training package. Direct transfer of skills learnt in the simulation training to the real-world operating theater, with consequent patient benefit, was reported. Cadaveric simulation in the UK training system of orthopedics may be of greatest utility at around the PGY 4 stage, at which point operative fluency, independence, and confidence can be rapidly improved in the cadaveric laboratory, to enable the attainment of competence in index trauma operations.

Cadaveric Simulation Training in Cardiothoracic Surgery: A Systematic Review

Simulation training has become increasingly relevant in the educational curriculum of surgical trainees. The types of simulation models used, goals of simulation training, and an objective assessment of its utility and effectiveness are highly variable. The role and effectiveness of cadaveric simulation in cardiothoracic surgical training has not been well established. The objective of this study was to evaluate the current medical literature available on the utility and the effectiveness of cadaveric simulation in cardiothoracic surgical residency training. A literature search was performed using PubMed, Cochrane Library, Embase, Scopus, and CINAHL from inception to February 2019. Of the 362 citations obtained, 23 articles were identified and retrieved for full review, yielding ten eligible articles that were included for analysis. One additional study was identified and included in the analysis. Extraction of data from the selected articles was performed using predetermined data fields, including study design, study participants, simulation task, performance metrics, and costs. Most of these studies were only descriptive of a cadaveric or perfused cadaveric simulation model that could be used to augment clinical operative training in cardiothoracic surgery. There is a paucity of evidence in the literature that specifically evaluates the utility and the efficacy of cadavers in cardiothoracic surgery training. Of the few studies that have been published in the literature, cadaveric simulation does seem to have a role in cardiothoracic surgery training beyond simply learning basic skills. Additional research in this area is needed.

Aortic inflation with agar injection is a useful method of cadaveric preparation which creates a mediastinal anatomy that better mimics the living body for surgical training

In cadavers, even Thiel-embalmed cadavers, the arteries (especially the thoracic aorta) are extremely collapsed. This is in marked contrast to the state of the arteries in a living body. Aortic inflation is necessary to improve this unfavorable situation for anatomical observation or dissection. To inflate the aorta, we injected 500 ml of hot liquid agar into the aorta using a 18-Fr catheter inserted into the common femoral artery and subclavian artery. The injected agar then rapidly cools to room temperature and solidifies. As a result, the thoracic aorta remains sufficiently and constantly inflated in the mediastinum. This method is not only easy and inexpensive, but also useful and effective for achieving a life-like anatomy in cadavers used in surgical training for operations involving mediastinal organs, with the exception of the heart and great vessels.

Review of the First 108 Free Flaps at Public Health Concern Trust-NEPAL Hospitals: Challenges and Opportunities in Developing Countries

BACKGROUND

Free tissue transfer is one of the most important and essential techniques in reconstructive surgery. The underlying complexity, steep learning curve, high cost, and fear of failure make it very difficult to establish as a regular service in developing countries such as Nepal.

METHODS

A retrospective cohort study design was used to analyze the challenges with and opportunities for reconstructive surgery in Nepal. Medical records were reviewed for patient demographics, indications, types of free flaps, hospital stay, complications, and involvement of a microsurgery teaching workshop.

RESULTS

A total of 16 microsurgical workshops were carried out by 3 international organizations over the study period (2007-2017). Altogether 108 free flaps in 103 subjects were reviewed during the study period at different hospitals of the Public Health Concern Trust-NEPAL (phect-NEPAL) and National Trauma Center. Of 103 patients, 60 were males and 43 were females with an average age of 34.5 years (range, 8-73 years). The most common indications for microsurgical reconstruction were tumor, trauma, and burns. Radial artery forearm flap, anterolateral thigh flap, and free fibular flap were the most common types of flaps. Ten different types of flaps were performed. Four cases needed more than 1 flap; one of them needed 3 flaps. Flap success rate approached 90%. Four patients died in the hospital postoperatively.

CONCLUSION

Reconstructive microsurgery is challenging in Nepal and more generally in developing settings. However, persistent technical support such as training and workshops can make it feasible.

Mechanical and functional validation of a perfused, robot-assisted partial nephrectomy simulation platform using a combination of 3D printing and hydrogel casting

INTRODUCTION AND OBJECTIVES

There is a scarcity of high-fidelity, life-like, standardized and anatomically correct polymer-based kidney models for robot-assisted partial nephrectomy (RAPN) simulation training. The purpose of this technical report is to present mechanical and functional testing data as evidence for utilizing a perfused hydrogel kidney model created utilizing 3D printed injection casts for RAPN simulation and training.

METHODS

Anatomically correct, tumor-laden kidney models were created from 3D-printed casts designed from a patient's CT scan and injected with poly-vinyl alcohol (PVA). A variety of testing methods quantified Young's modulus in addition to comparing the functional effects of bleeding and suturing among fresh porcine kidneys and various formulations of PVA kidneys.

RESULTS

7% PVA at three freeze-thaw cycles (7%-3FT) was found to be the formula that best replicates the mechanical properties of fresh porcine kidney tissue, where mean(± SD) values of Young's modulus of porcine tissue vs 7%-3FT samples were calculated to be 85.97(± 35) kPa vs 80.97(± 9.05) kPa, 15.7(± 1.6) kPa vs 74.56(± 10) kPa and 87.46(± 2.97) kPa vs 83.4(± 0.7) kPa for unconfined compression, indentation and elastography testing, respectively. No significant difference was seen in mean suture tension during renorrhaphy necessary to achieve observable hemostasis and capsular violation during a simulated perfusion at 120 mmHg.

CONCLUSIONS

This is the first study to utilize extensive material testing analyses to determine the mechanical and functional properties of a perfused, inanimate simulation platform for RAPN, fabricated using a combination of image segmentation, 3D printing and PVA casting.

Systematic review of the current status of cadaveric simulation for surgical training

Background

There is growing interest in and provision of cadaveric simulation courses for surgical trainees. This is being driven by the need to modernize and improve the efficiency of surgical training within the current challenging training climate. The objective of this systematic review is to describe and evaluate the evidence for cadaveric simulation in postgraduate surgical training.

Methods

A PRISMA‐compliant systematic literature review of studies that prospectively evaluated a cadaveric simulation training intervention for surgical trainees was undertaken. All relevant databases and trial registries were searched to January 2019. Methodological rigour was assessed using the widely validated Medical Education Research Quality Index (MERSQI) tool.

Results

A total of 51 studies were included, involving 2002 surgical trainees across 69 cadaveric training interventions. Of these, 22 assessed the impact of the cadaveric training intervention using only subjective measures, five measured impact by change in learner knowledge, and 23 used objective tools to assess change in learner behaviour after training. Only one study assessed patient outcome and demonstrated transfer of skill from the simulated environment to the workplace. Of the included studies, 67 per cent had weak methodology (MERSQI score less than 10·7).

Conclusion

There is an abundance of relatively low‐quality evidence showing that cadaveric simulation induces short‐term skill acquisition as measured by objective means. There is currently a lack of evidence of skill retention, and of transfer of skills following training into the live operating theatre.

A novel model for minimally invasive left ventricular assist device implantation training

Background: Significant advances in minimally invasive implantation of mechanical circulatory support devices have been made. These approaches are technically challenging and associated with a learning curve. Simulation and training opportunities in these techniques are limited. We developed a high-fidelity novel model for minimally invasive left ventricular assist device implantation.Material and methods: Using a modified inanimate simulator (LSI SOLUTIONS^®) and an animal tissue model, a hybrid simulator was created, with a porcine ex vivo heart secured within the inanimate simulator in the normal anatomic position. Key components of the minimally invasive left ventricular assist device implantation were performed, including left ventricular apical coring, attachment of the apical ring, attachment of the assist device, and creation of the aortic-outflow graft anastomosis.Results: A novel composite inanimate and tissue model for minimally invasive left ventricular assist device implantation was successfully developed. These simulation techniques were reproducible, and the model demonstrated ability to successfully simulate key components of the procedure.Conclusions: This high-fidelity, reproducible hybrid model allows for crucial components of minimally invasive LVAD implantation to be performed. This model has the potential to be used as an adjunct to surgical training, providing a safe and controlled learning environment for trainees to acquire skills in minimally invasive LVAD implantation.

A Reusable Perfused Human Cadaver Model for Surgical Training: An Initial Proof of Concept Study

OBJECTIVES

Today's surgical trainees have less exposure to open vascular and trauma procedures. Lightly embalmed cadavers may allow a reusable model that maximizes resources and allows for repeat surgical training over time.

METHODS

This was a three-phased study that was conducted over several months. Segments of soft-embalmed cadaver vessels were harvested and perfused with tap water. To test durability, vessels were clamped, then an incision was made and repaired with 5-0 polypropylene. Tolerance to suturing and clamping was graded. In a second phase, both an arterial-synthetic graft and an arterial-venous anastomosis were performed and tested at 90 mmHg perfusion. In the final phase, lower extremity regional perfusion was performed and vascular control of a simulated injury was achieved.

RESULTS

Seven arteries and six veins from four cadavers were explanted. All vessels accommodated suture repair over 6 weeks. There was minor leaking at all previous clamp sites. In the anastomotic phase, vessels tolerated grafting, clamping, and perfusion without tearing or leaking. Regional perfusion provided a life-like training scenario.

CONCLUSIONS

Explanted vessels of soft-embalmed cadavers show adequate durability over time with realistic vascular surgery handling characteristics. This shows promise as initial proof of concept for a reusable perfused cadaver model. Further study with serial regional and whole-body perfusion is warranted.

A Randomized Controlled Trial using iTClamp, Direct Pressure, and Balloon Catheter Tamponade to Control Neck Hemorrhage in a Perfused Human Cadaver Model

BACKGROUND

Penetrating neck wounds are common in the civilian and military realms. Whether high or low velocity, they carry a substantial morbidity and mortality rate.

OBJECTIVES

We endeavored to ascertain whether the iTClamp is equivalent to direct manual pressure (DMP) and Foley catheter balloon tamponade (BCT).

METHODS

Using a perfused cadaver, a 4.5-cm wound was made in Zone 2 of the neck with a 1-cm carotid arteriotomy. Each of the hemorrhage control modalities was randomized and then applied to the wound separately. Time to apply the device and fluid loss with and without neck motion was recorded.

RESULTS

There was no significant difference between the fluid loss/no movement (p > 0.450) and fluid loss/movement (p > 0.215) between BCT and iTClamp. There was significantly more fluid lost with DMP than iTClamp with no movement (p > 0.000) and movement (p > 0.000). The iTClamp was also significantly faster to apply than the Foley (p > 0.000).

CONCLUSIONS

The iTClamp and BCT were associated with significantly less fluid loss than DMP in a perfused cadaver model. The iTClamp required significantly less time to apply than the BCT. Both the iTClamp and the BCT were more effective than simple DMP. The iTClamp offers an additional option for managing hard-to-control bleeding in the neck.

Pathophysiology Study of Filler-Induced Blindness

Background

A number of authors have proposed retrograde arterial embolism as the responsible mechanism for filler-induced blindness. However, no previous human study has substantiated this proposed mechanism.

Objectives

The aim of this study was to investigate the pathophysiology of filler-induced blindness using a fresh cadaver perfusion technique.

Methods

A fresh cadaver head perfusion model that simulates both physiologic blood pressure and flow rate of the carotid artery, ophthalmic artery, and supratrochlear artery was used. The common carotid artery was cannulated and the internal jugular vein exposed for open venous drainage. A plasma-based perfusate was circulated through the cadaver head, which was connected to a perfusion system consisting of a roller pump, preload reservoir, and pressure monitor. The hyaluronic acid filler mixed with methylene blue was injected into the cannulated superficial branch of the supratrochlear artery. Cadaver dissection, angiographic study, and histology were used to investigate filler-induced blindness.

Results

Cannulation of the superficial branch of the supratrochlear artery was successful in all six cadavers. Emboli to the ophthalmic artery was successfully demonstrated in the three out of 6 fresh cadaver heads. The C-arm angiogram documented a cut-off sign in the ophthalmic artery due to hyaluronic acid filler emboli. An average intravascular volume of the intraorbital part of the supratrochlear artery was 50.0 µL. The average depth of location of the superficial branch of the supratrochlear artery from the epidermal surface was 1.5 mm.

Conclusions

Our cadaveric study demonstrated that retrograde hyaluronic acid filler emboli to the ophthalmic artery could be produced by the cannulation of the supratrochlear artery. The superficial location of the supratrochlear artery, the rich vasculature surrounding it, and the variability in the anatomy make this possible.

Redefining the Anatomic Boundaries for Safe Dissection of the Skin Paddle in a Gracilis Myofasciocutaneous Free Flap: An Indocyanine Green Cadaveric Injection Study

The gracilis free flap remains a versatile option in the reconstructive ladder. The flap itself can be harvested with or without a skin paddle. The gracilis myocutaneous free flap, however, is known for partial skin flap necrosis, especially in the distal one-third of the skin island. The gracilis myofasciocutaneous flap has been previously described as a technique to improve perfusion to the skin by harvesting surrounding deep fascia in a pedicled flap. However, limitations to this study required injection of multiple pedicles to demonstrate its perfusion. We demonstrate a novel technique using a cadaveric model that shows perfusion through injection via a single dominant pedicle (medial circumflex) with a large cutaneous paddle (average 770 cm²) with included deep fascia, using indocyanine green and near-infrared imaging. For comparison, we are also able to confirm the lack of perfusion to the distal cutaneous paddle when the fascia is not harvested, correlating with previous findings and ink injection studies. This novel technique is versatile, relatively inexpensive, and can demonstrate perfusion patterns via perforasomes that were otherwise not possible from previous techniques. Additionally, real-time imaging is possible, helping to elucidate the sequence of flow into the flap and potentially predict areas of flap necrosis.

Teaching courses in the management of visceral trauma

Several changes introduced in the management of trauma during the last two decades have considerably decreased the practical exposure to bleeding trauma patients by residents and young surgeons. Hemorrhage still represents the second cause of death from trauma worldwide, and the surgical maneuvers required for its control must be learned and practised in specific courses. These courses address the "second hour" of trauma, beyond ATLS^©, and also emphasize the decision-making process, communication among team members, and discussion of clinical scenarios. The significant progress made in simulation technologies and virtual reality systems have yet to replace living tissue models to train surgeons in the rapid control of active bleeding, although that replacement is probably not far away.

Vascularized dermal autograft for the treatment of irreparable rotator cuff tears

BACKGROUND

Irreparable rotator cuff tears (IRCTs) are a challenging problem with diverse treatment modalities. We propose a technique for the treatment of IRCTs in which a vascularized dermal autograft is transferred to the posterosuperior region of the rotator cuff using the supraclavicular artery (SCA) island flap.

MATERIALS AND METHODS

Dissection of 11 fresh cadavers (19 shoulders) was performed, and the SCA island flap was harvested in all specimens. A full-thickness posterosuperior rotator cuff defect was created, and the flap was tunneled under the acromion and secured into position over the defect using multiple suture anchors. Simulated flap perfusion was then assessed, and flap measurements were recorded.

RESULTS

There were 4 male and 7 female cadavers (19 shoulders). Flap perfusion was assessed in 10 shoulders. On average, the flap thickness was 4.7 mm (range, 3.5-7.1 mm); width, 32.6 mm (range, 25.5-38.0 mm); and length, 169.2 mm (range, 132.0-235.0 mm). The average distance from the flap tip to the Neviaser portal was 76.2 mm (range, 48.0-99.6 mm), and that from the flap tip to the anterolateral acromial edge was 54.1 mm (range, 29.5-75.1 mm). The pedicle-to-footprint distance was 113.7 mm (range, 88.5-147.0 mm). The average flap length exceeded the pedicle-to-footprint distance by 55.5 mm (range, 43.5-88.0 mm), indicating adequate excursion of the flap. All flaps demonstrated adequate simulated perfusion after fixation.

CONCLUSION

The SCA island flap may be an option for a vascularized dermal autograft for IRCTs, as shown in this cadaveric study. This illustrates a possible technique with vascular viability.