Fresh frozen cadavers: an under-utilized resource in laparoscopic colorectal training in the United Kingdom

A novel model for hands-on laparoscopic pelvic surgery training on Genelyn-embalmed body: an initial feasibility study

The human donor body provides a well-accepted ex vivo model for laparoscopic surgical training. Unembalmed, or fresh-frozen, bodies comprise high-fidelity models. However, their short life span and high cost relatively limit the hands-on training benefits. In contrast, soft embalmed body of donors has a relatively longer usability without compromising tissue flexibility. This study reports the initial experience of the utility and feasibility of human donor Genelyn-embalmed body as a novel soft-embalmed cadaveric model for laparoscopic surgical training. An expert laparoscopic surgeon, who organised many fresh-frozen body donor courses, performed deep laparoscopic pelvic dissection and laparoscopic surgical tasks including suturing and electrosurgery on a single Genelyn-embalmed body. The three sessions were performed over a course of 3 weeks. The body was fully embalmed using the Genelyn technique. The technique consisted of a single-point closed arterial perfusion of embalming solution via the carotid artery with no further exposure to or immersion in embalming fluids thereafter. The donor's Genelyn-embalmed body provided a feasible model for laparoscopic surgical training. Initial experience shows evidence of this model being feasible and realistic. There was reproducibility of these qualities across a minimum of 3 weeks in this single-donor study. Initial experience shows that donor's Genelyn-embalmed body provides a novel model for laparoscopic surgical training, which possesses fidelity and is feasible for laparoscopic training. While further studies are needed to validate these findings, this technical note provides perspectives from an expert trainer regarding this model and provides a photographic and videographic atlas of this model's use in laparoscopy.

Current and potential use of fresh frozen cadaver in surgical training and anatomical education

As surgical procedures continue to be more complex, the need for more effective training in anatomy has increased. The study of anatomy plays a significant role in the understanding of the human body as well as in basic and advanced clinical training. Among the different cadaver models, fresh frozen cadavers (FFCs) are known for their realistic tissue quality. The purpose of this article was to review and summarize the preparation procedures for and reported cases involving FFCs. PubMed, Scopus, Medline, and Web of Science were searched for relevant studies. The preparation procedures were divided into five steps: washing, irrigation, freezing, defrosting, and arterial infusion. Not all steps were reported to be mandatory, but omitting one or more could result in a loss of quality. FFCs were reported to be used for various purposes: undergraduate education, general surgery training, vascular surgery training, minimal access surgery (laparoscopic surgery) training, and microsurgery training. In all categories, expert opinions and statistical analyses indicated successful outcomes. The reasons for high satisfaction with FFCs included realistic texture, capability of reenacting actual operations, and accuracy of anatomical locations. The results also revealed the importance and advantages of the dissection courses in surgical training. Since the direct comparison between cadaver models is insufficient, future studies regarding this topic are deemed necessary. In addition, it would be advantageous to develop methods to improve FFC quality, or ideas to optimize this model for certain purposes.

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.

Preservation of neural tissue with a formaldehyde-free phenol-based embalming protocol

The adverse effects formaldehyde fixation has on tissues both gross anatomically and histologically are well documented. Consequently, researchers are seeking alternative embalming techniques that better preserve in vivo characteristics of tissues. Phenol-based embalming is one method that has shown promise in its ability to adequately preserve the in vivo qualities of tissues through preliminary explorations at the gross anatomical level. The literature on phenol-based embalming is currently scarce, especially with regard to its effects on tissues at the microscopic level. For the current study we aimed to document the histologic effects of a formaldehyde-free phenol-based embalming solution on neural tissue, with the hope of providing novel insight into the effects of soft-embalming on tissues at the microscopic level. Cerebral and cerebellar tissue obtained from porcine brains was fixed in phenol- and formaldehyde-based fixatives; the latter served as a control. Fixed samples were processed for histological analysis. The phenol-based embalming solution provided excellent preservation of the cerebral and cerebellar tissue morphology. Of note was the decrease in separation artifact seen in both tissue types relative to the control tissue, as well as anomalous circular artifacts in the white matter. The results of this study indicate that the phenol-based embalming solution preserves neural tissue at the histological level, perhaps superiorly in many aspects when compared to the formaldehyde-fixed samples. Further investigations of both gross anatomy and histology are recommended on the basis of these promising new findings to determine its potential utilities within research and education. Clin. Anat. 32:224-230, 2019. © 2018 Wiley Periodicals, Inc.

Mentor Tutoring: An Efficient Method for Teaching Laparoscopic Colorectal Surgical Skills in a General Hospital

OBJECTIVE

We retrospectively assessed the efficacy of our mentor tutoring system for teaching laparoscopic colorectal surgical skills in a general hospital.

MATERIALS AND METHODS

A series of 55 laparoscopic colectomies performed by 1 trainee were evaluated. Next, the learning curves for high anterior resection performed by the trainee (n=20) were compared with those of a self-trained surgeon (n=19).

RESULTS

Cumulative sum analysis and multivariate regression analyses showed that 38 completed cases were needed to reduce the operative time. In high anterior resection, the mean operative times were significantly shorter after the seventh average for the tutored surgeon compared with that for the self-trained surgeon. In cumulative sum charting, the curve reached a plateau by the seventh case for the tutored surgeon, but continued to increase for the self-trained surgeon.

CONCLUSIONS

Mentor tutoring effectively teaches laparoscopic colorectal surgical skills in a general hospital setting.

What to consider when designing a laparoscopic colorectal training curriculum: a review of the literature

Multiple studies have demonstrated the benefits of laparoscopic colorectal surgery (LCS), but in several countries it has still not been widely adopted. LCS training is associated with several challenges, such as patient safety concerns and a steep learning curve. Current evidence may facilitate designing of efficient training curricula to overcome these challenges. Basic training with virtual reality simulators has witnessed meteoric advances and may be essential during the early parts of the learning curve. Cadaveric and animal model training still constitutes an indispensable training tool, due to a higher degree of difficulty and greater resemblance to real operative conditions. In addition, recent evidence favors the use of novel training paradigms, such as proficiency-based training, case selection and modular training. This review summarizes the recent advances in LCS training and provides the evidence for designing an efficient training curriculum to overcome the challenges of LCS training.

Laparoscopic training model using fresh human cadavers without the establishment of penumoperitoneum

BACKGROUND:

Laparoscopy is a well-established alternative to open surgery for treating many diseases. Although laparoscopy has many advantages, it is also associated with disadvantages, such as slow learning curves and prolonged operation time. Fresh frozen cadavers may be an interesting resource for laparoscopic training, and many institutions have access to cadavers. One of the main obstacles for the use of cadavers as a training model is the difficulty in introducing a sufficient pneumoperitoneum to distend the abdominal wall and provide a proper working space. The purpose of this study was to describe a fresh human cadaver model for laparoscopic training without requiring a pneumoperitoneum.

MATERIALS AND METHODS AND RESULTS:

A fake abdominal wall device was developed to allow for laparoscopic training without requiring a pneumoperitoneum in cadavers. The device consists of a table-mounted retractor, two rail clamps, two independent frame arms, two adjustable handle and rotating features, and two frames of the abdominal wall. A handycam is fixed over a frame arm, positioned and connected through a USB connection to a television and dissector; scissors and other laparoscopic materials are positioned inside trocars. The laparoscopic procedure is thus simulated.

CONCLUSION:

Cadavers offer a very promising and useful model for laparoscopic training. We developed a fake abdominal wall device that solves the limitation of space when performing surgery on cadavers and removes the need to acquire more costly laparoscopic equipment. This model is easily accessible at institutions in developing countries, making it one of the most promising tools for teaching laparoscopy.

Development and evaluation of a cadaveric training curriculum for low rectal cancer surgery in the English LOREC National Development Programme

AIM

The National Development Programme for Low Rectal Cancer in England (LOREC) was commissioned in response to wide variation in the outcome of patients with low rectal cancer. One of the aims of LOREC was to enhance surgical techniques in managing low rectal cancer. This study reports on the development and evaluation of a novel national technical skills cadaveric training curriculum in extralevator abdominoperineal excision.

METHOD

Three sites were commissioned for the cadaveric workshops, each delivering the same training curriculum. Training was undertaken in pairs using a fresh-frozen cadaveric model under the supervision of expert mentors. Global assessment score (GAS) forms were developed to promote reflective learning. Feedback on the impact of the workshop was obtained from a sample of delegates at the end of the course, and also after 3-23 months via an online questionnaire.

RESULTS

Overall 112 consultant colorectal surgeons attended one of 15 cadaveric technical skills training workshops. Seventy-six per cent of delegates reported easy identification of anatomy in the cadaveric model; 67% found tissue planes easy to interpret. Ninety-six per cent of delegates felt the workshop would influence their future practice; 96% reported increased awareness of important anatomy. Only 2% of delegates wished to pursue supplementary formal training from LOREC.

CONCLUSION

Fresh-frozen cadavers could provide an effective training model for low rectal surgery. A structured 1-day cadaveric workshop has facilitated the dissemination of technical skills for management of low rectal cancer. Attending the cadaveric workshop enhanced delegates' confidence in performing this procedure.

On the suitability of Thiel cadavers for natural orifice transluminal endoscopic surgery (NOTES): surgical training, feasibility studies, and anatomical education

BACKGROUND

Surgical training in virtual, animal and cadaver models is essential for minimally invasive surgery. Thiel cadavers are suitable for laparoscopy, but there are few data about the use of embalmed (Tutsch method) and slightly embalmed (Thiel method) cadavers in procedures of Natural Orifice Transluminal Endoscopic Surgery (NOTES), which are usually developed and learned on swine models and fresh frozen cadavers. The aim of this study was thus to assess the use of these cadavers for NOTES approaches.

METHODS

The following surgical procedures were evaluated: transanal total mesorectal excision (four cadavers: one Tutsch, two Thiel, one fresh frozen), transanal ileorectal bypass (five cadavers: one Tutsch, three Thiel, one fresh frozen), and transvaginal appendectomy (two Tutsch cadaver).

RESULTS

The Thiel method ensured tissue flexibility and consistency suitable for performing the above surgical procedures with good results and without complications, with only a small increase in rigidity with respect to fresh specimens. Cadavers embalmed with higher formalin concentrations (Tutsch method) were more difficult to use, due to high tissue rigidity and resistance of the abdominal wall to pneumoperitoneum, although NOTES accesses were possible.

CONCLUSIONS

Thiel cadavers are suitable for transanal/transrectal and transvaginal NOTES approaches, for training surgical residents/specialists and also for surgical research. In minimally invasive surgery (and particularly in NOTES), integration between cadaver (fresh frozen and/or Thiel) and animal models would represent the gold standard, allowing guaranteed knowledge of and respect for human surgical anatomy and correct management of surgery on living subjects. NOTES approaches to human cadavers may also be proposed for the anatomical education of medical students.

Enhancing paramedics procedural skills using a cadaveric model

BACKGROUND

Paramedic education has evolved in recent times from vocational post-employment to tertiary pre-employment supplemented by clinical placement. Simulation is advocated as a means of transferring learned skills to clinical practice. Sole reliance of simulation learning using mannequin-based models may not be sufficient to prepare students for variance in human anatomy. In 2012, we trialled the use of fresh frozen human cadavers to supplement undergraduate paramedic procedural skill training. The purpose of this study is to evaluate whether cadaveric training is an effective adjunct to mannequin simulation and clinical placement.

METHODS

A multi-method approach was adopted. The first step involved a Delphi methodology to formulate and validate the evaluation instrument. The instrument comprised of knowledge-based MCQs, Likert for self-evaluation of procedural skills and behaviours, and open answer. The second step involved a pre-post evaluation of the 2013 cadaveric training.

RESULTS

One hundred and fourteen students attended the workshop and 96 evaluations were included in the analysis, representing a return rate of 84%. There was statistically significant improved anatomical knowledge after the workshop. Students' self-rated confidence in performing procedural skills on real patients improved significantly after the workshop: inserting laryngeal mask (MD 0.667), oropharyngeal (MD 0.198) and nasopharyngeal (MD 0.600) airways, performing Bag-Valve-Mask (MD 0.379), double (MD 0.344) and triple (MD 0.326,) airway manoeuvre, doing 12-lead electrocardiography (MD 0.729), using laryngoscope (MD 0.726), using Magill® forceps to remove foreign body (MD 0.632), attempting thoracocentesis (MD 1.240), and putting on a traction splint (MD 0.865). The students commented that the workshop provided context to their theoretical knowledge and that they gained an appreciation of the differences in normal tissue variation. Following engagement in/ completion of the workshop, students were more aware of their own clinical and non-clinical competencies.

CONCLUSIONS

The paramedic profession has evolved beyond patient transport with minimal intervention to providing comprehensive both emergency and non-emergency medical care. With limited availability of clinical placements for undergraduate paramedic training, there is an increasing demand on universities to provide suitable alternatives. Our findings suggested that cadaveric training using fresh frozen cadavers provides an effective adjunct to simulated learning and clinical placements.