Continuous Flow Perfused Cadaver Model for Endovascular Training, Research, and Development

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.

Endoscopic retrograde cholangiopancreatography training and education

Endoscopic retrograde cholangiopancreatography (ERCP) is an advanced endoscopic technique used to diagnose and treat biliary and pancreatic diseases. It is one of the most technically demanding endoscopic procedures. ERCP training programs must ensure trainees have adequate knowledge of the anatomy and physiology associated with biliopancreatic diseases. The variety of ERCP procedures included in training programs should provide sufficient basic training for novice trainees and advanced training for experienced endoscopists. The main endoscopic procedures should be trained in ascending order of difficulty. Incorporating models capable of simulating various clinical and anatomical conditions could provide an effective means of fulfilling training requirements, although they are not easily available due to expensive facilities and void of standard assessment. Competency assessment is crucial in ERCP training to ensure trainees can independently and safely perform ERCP. Because of the rapid advancement of diagnostic and therapeutic methods, postgraduate training is critical for ERCP practitioners. Once certificates are attained, practitioners are solely responsible for maintaining their competency, credentialing, and quality.

Cadaveric aortic aneurysm creation: A life-like model for training endovascular repair

The recent decline in RAAA incidence and the fast paced scenario with associated challenges regarding training calls for initiative for a better training environment to maximize learning. This led us to the creation of a pulsatile human cadaveric RAAA model. Fresh frozen cadaver was used to create RAAA with BioTissue in hybrid suite with ability to perform CBCTA for sizing. As a proof of concept, the model was used to perform REVAR with proximal CODA balloon control. The model proved to be feasible and we believe it is a better environment to train and gain adequate proficiency in RAAA management.

Continuous extracorporeal femoral perfusion model for intravascular ultrasound, computed tomography and digital subtraction angiography

OBJECTIVES

We developed a novel human cadaveric perfusion model with continuous extracorporeal femoral perfusion suitable for performing intra-individual comparison studies, training of interventional procedures and preclinical testing of endovascular devices. Objective of this study was to introduce the techniques and evaluate the feasibility for realistic computed tomography angiography (CTA), digital subtraction angiography (DSA) including vascular interventions, and intravascular ultrasound (IVUS).

METHODS

The establishment of the extracorporeal perfusion was attempted using one formalin-fixed and five fresh-frozen human cadavers. In all specimens, the common femoral and popliteal arteries were prepared, introducer sheaths inserted, and perfusion established by a peristaltic pump. Subsequently, we performed CTA and bilateral DSA in five cadavers and IVUS on both legs of four donors. Examination time without unintentional interruption was measured both with and without non-contrast planning CT. Percutaneous transluminal angioplasty and stenting was performed by two interventional radiologists on nine extremities (five donors) using a broad spectrum of different intravascular devices.

RESULTS

The perfusion of the upper leg arteries was successfully established in all fresh-frozen but not in the formalin-fixed cadaver. The experimental setup generated a stable circulation in each procedure (ten upper legs) for a period of more than six hours. Images acquired with CT, DSA and IVUS offered a realistic impression and enabled the sufficient visualization of all examined vessel segments. Arterial cannulating, percutaneous transluminal angioplasty as well as stent deployment were feasible in a way that is comparable to a vascular intervention in vivo. The perfusion model allowed for introduction and testing of previously not used devices.

CONCLUSIONS

The continuous femoral perfusion model can be established with moderate effort, works stable, and is utilizable for medical imaging of the peripheral arterial system using CTA, DSA and IVUS. Therefore, it appears suitable for research studies, developing skills in interventional procedures and testing of new or unfamiliar vascular devices.

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’.

Cadaver Simulation is Associated with Increased Comfort in Performing Open Vascular Surgery Among Integrated Vascular Surgery (0+5) Residents and Recent Graduates

BACKGROUND

With the evolution in vascular surgery toward increased endovascular therapy and decreased open surgical training, comfort with open procedures by current trainees is declining. A proposed method to improve this discomfort is simulator training. We hypothesized that open, cadaver, and endovascular surgery simulation would be associated with increased self-perceived comfort in performing corresponding procedures.

METHODS

Integrated (0 + 5) vascular surgery residents and recent graduates in the United States were asked to complete a survey quantifying comfort via a Likert scale with procedures and experience with simulation training. Simulation groups were then matched using coarsened exact matching. Ordinal logistic regression assessed the association between simulation experience and comfort in performing procedures.

RESULTS

Surveys were completed by 68 trainees and 20 attending surgeons in their first 5 years of practice. On unmatched analyses, there were no significant differences in comfort in performing any open or endovascular aorto-mesenteric or peripheral vascular procedures between respondents who reported experience with open or endovascular simulation, respectively. However, respondents who reported cadaver simulation experience (58%, 51/88) had a significantly higher reported comfort score performing open juxtarenal aortic repair (2.4 vs. 1.7), superior mesenteric artery thrombectomy or bypass (2.5 vs. 1.9), inferior vena cava or iliac vein repair (2.2 vs. 1.7), axillary-femoral artery bypass (3.4 vs. 2.5), femoral-popliteal artery bypass (3.7 vs. 2.8), and inframalleolar artery bypass (2.8 vs. 2.1; all P < 0.05). After matching on training level, number of abdominal cases completed, and number of open vascular cases completed, ordinal logistic regression demonstrated that previous cadaver simulation was significantly associated with increased comfort in performing open aortic repairs, venous repair, visceral revascularization, and peripheral bypasses.

CONCLUSIONS

In this nationally representative sample, cadaver, but not open or endovascular, simulation was associated with increased comfort in performing open vascular surgery. Providing cadaver simulation to trainees may help to improve comfort levels in performing open surgery. Integrated vascular surgery training programs should consider implementing these experiences into their curriculum.

Training in endoscopic retrograde cholangio-pancreatography: a critical assessment of the broad scenario of training programs and models

Introduction: Endoscopic Retrograde Cholangio-Pancreatography (ERCP) applications are rapidly evolving toward increasingly complex therapeutic approaches alongside with technological innovations. There are no globally agreed indications on the ERCP training path, which often requires too much time and does not always guarantee adequate skills.Areas covered: Frequency and difficulty of execution are the main objective criteria on which to draw up a training program: novel trainees should approach ERCP first through the simplest and most frequent procedures. An extensive use of training models would reduce the patient's performer-related risks. Amongst a wide variety of models, mechanical simulators have received large approval. In fact, they can be best-suited to each trainee's learning curve thanks to their precision and safety and by virtue of the unlimited repeatability of their use. However, more solid evidences are still needed.Expert opinion: Hands-on ERCP training should systematically employ mechanical simulators at least in the early stages of the learning process. An implementation of these models through sensors that objectively detect abnormalities in the movements would provide detailed feedbacks and deeper awareness. Simulators might also be useful for expert endoscopists to refine their skills. Rapid prototyping and 3D printing might be the way to create customized training models for successful training programs.

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.