Advanced training in laparoscopic gastrointestinal surgical procedures using Genelyn®-embalmed human cadavers: A novel model.

BACKGROUND: Human cadaver is ideal for learning and acquiring new surgical skills. While cadavers preserved using Thiel's embalming method are commonly used for training in laparoscopic surgery, it is a cumbersome technique. We report our experience of using Genelyn®-embalmed cadavers for training in advanced laparoscopic gastrointestinal procedures.
MATERIALS AND METHODS: A cross-sectional satisfaction survey corresponding to level 1 of the Kirkpatrick model for training evaluation was performed among 19 participants of advanced laparoscopy surgical skills training workshop, in December 2019, using Genelyn®-embalmed cadavers. Visual, haptic and tactile characteristics of the organs and tissues were assessed along with overall satisfaction of the workshop using Likert scale.
RESULTS: Five Genelyn®-embalmed cadavers were used for the workshop. All the 19 participants perceived that the cadavers were odourless and allowed adequate insufflation for laparoscopic procedures. Most of the participants(n=16, 84%) agreed that the appearance and tactile fidelity of the solid organs, luminal structures and tissues in Genelyn®-embalmed cadavers were similar to that of a live patient. There was a strong agreement among participants that the workshop will help improve the laparoscopic skills(median Likert score-4).
CONCLUSION: The participants of the surgical skill training workshop felt that the Genelyn®-embalmed cadavers were ideal for use in practicing advanced laparoscopic procedures.

INTRODUCTION

Minimally invasive surgery using a laparoscopic approach is preferred for most of the elective abdominal procedures as it reduces post-operative pain, enhances recovery and improves post-operative outcomes. However, learning laparoscopy skills is a challenging task as it poses multiple visual(lack of depth perception, decoupling and reduced field of vision) and mechanical constraints(limited degree of freedom and diminished tactile feedback). The learning curve for laparoscopic skills is long and time intensive and the skills cannot be directly learnt on live patients without compromising their safety.[1] The existing postgraduate residency programmes are grossly inadequate to teach basic and advanced laparoscopic surgical skills. Hence, there is a general agreement among surgeons that additional training on simulated patients is essential to improve the advanced laparoscopic surgical skills.[2] Simulation is an essential prerequisite for learning and practicing new surgical skills, and it significantly improves patient safety.[3]

For learning the basic laparoscopic skills, computer-based low fidelity and high-fidelity virtual reality(VR) simulators serve as a safe, ethical and repeatable learning tool. The real-time feedback provided by VR simulators facilitates an objective assessment of the learning skills.[4] However, crucial training features such as the influence of patient positioning on surgical steps, setup of equipment, optimal trocar placement, creation of pneumoperitoneum and appropriate tissue handling with more realistic haptic feedback cannot be learnt using VR simulators.[5] Another disadvantage of the VR model is that the fulcrum effect of the anterior abdominal wall on the laparoscopic instruments cannot be learnt.[6]

Anaesthetised animal models, formalin-embalmed cadavers and Thiel’s embalmed cadavers are currently available options for training in advanced laparoscopic skills. Anaesthetised animal models offer a good simulation with accurate colour, consistency and plasticity of the organs. In addition, animal models allow surgeons to practice the technique of securing haemostasis during surgery.[7] However, the anatomical dissimilarity between animals and humans and the need for sacrificing the animals remain a limitation.[58] Advanced laparoscopic surgical skill training is not possible in cadavers preserved using conventional embalming fluids such as formalin due to alteration in the colour and tissue rigidity.[9] Although the preservation of cadavers using Thiel’s embalming gives good results, it is a difficult procedure requiring meticulous preparation and application into the cadaver.[810] Genelyn® is a relatively new embalming fluid to preserve cadavers for surgical skill training. In our quest to find out an ideal preservative for cadavers used in surgical skill training, we started using Genelyn® in surgical skill training. The present manuscript intends to briefly describe the methodology of embalming and storage of Genelyn®-embalmed cadavers and present the results of usage of Genelyn®-embalmed cadavers for teaching advanced laparoscopic procedures in gastrointestinal(GI) surgery. This study corresponds to level 1(out of 4) of the Kirkpatrick model for training evaluation as it describes the participant’s reaction towards a laparoscopic skill training programme along with the subjective perception of the haptic characteristics of Genelyn®-embalmed cadavers.

MATERIALS AND METHODS

The surgical gastroenterology department in collaboration with the department of anatomy organised a 2-day advanced hands-on cadaveric course on laparoscopic GI surgery. General and GI surgeons from across the country attended the course conducted in December 2019.

Cadavers

The cadavers were procured from the voluntary whole-body donations made to the department of anatomy. The cadavers were embalmed using Genelyn® solution which is a proprietary solution manufactured by an Australian-based company. Some of the constituents of the Genelyn® embalming solution reported in the literature are formaldehyde, methanol and 2-Butoxyethanol.[9] However, the full composition is not revealed by the manufacturers. Each Genelyn®-embalming solution kit consists of 2500 ml of embalming solution and costs INR 7500. One Genelyn® embalming kit is diluted with 5000 ml of distilled water to make a total of 7500 ml of embalming solution that can be used to preserve an average-built 70 kg human cadaver. Cadavers are embalmed using Genelyn® embalming solution within 24 h after death. Voluntarily donated bodies were specifically chosen for Genelyn® embalming as this embalming technique needs fresh cadavers that generally have clear blood vessels for the perfusion of arterial embalming solution and venous drainage of blood and embalming solution. Arterial embalming was done using the common carotid artery, and supplemental hypodermic injection was done to adequately perfuse the cadaver, ensuring even distribution to all parts of the body. The cadavers were then transferred to plastic body bags and stored in cold chambers at 4°C. Once in a week, the cadavers were cleaned using a surface disinfectant supplied by the Genelyn® manufacturer, till their utilisation for the workshop. The median time interval between the embalming of the cadavers and their utilisation for the workshop was 14 weeks.

Workshop structure

The eligibility criteria for workshop participants are that surgeons should have:

Completed or pursuing super-speciality course(M.Ch/DNB) in GI surgery or general surgeons who regularly perform GI surgery

Assisted at least 25 laparoscopic GI procedures

Completed formal basic laparoscopy training course using VR simulators or training course in animals.

The criteria are framed to ensure that the participants are well versed with the basic laparoscopic techniques. Five laparoscopy stations were arranged with a complete laparoscopic video system and instruments. The cadavers were positioned on the tables with head-end or leg elevation as per the surgical procedure. The workshop started with a short lecture on the technique of Genelyn® embalming, followed by operative videos highlighting the important steps of the surgical procedure to be performed by the participants. One cadaver was allotted to a team of three to four surgeons guided by one faculty. On the 1st day, the participants performed laparoscopic Nissen fundoplication, laparoscopic subtotal gastrectomy, laparoscopic splenectomy and laparoscopic hepaticojejunostomy. On the 2nd day, laparoscopic right hemicolectomy, laparoscopic anterior resection and laparoscopic left lateral sectionectomy were performed by the surgeons. During the entire session, the participants at each station were guided by the respective faculty. At the end of the workshop, the participants and the resource persons were asked to complete a questionnaire based on their experience of performing surgical procedures in the Genelyn®-embalmed cadavers.

Questionnaire

A team of two anatomists prepared the questionnaire after individually reviewing relevant literature. It included three domains namely(1) profile of participants,(2) subjective perception regarding the haptic and tactile characteristics of soft embalmed cadaver and(3) perceived learning outcomes and satisfaction of the workshop. In an initial meeting, the questionnaire was discussed among the team of anatomists and modified as per the discussion. Later, in a second meeting, the questionnaire was discussed with a surgical gastroenterologist for final consensus.

The questionnaire was validated by an independent team of anatomists and surgical gastroenterologists not involved in the preparation of the questionnaire. The questionnaire was then administered to another independent anatomy faculty to test for its repeatability. After completion of all the surgical procedures, the participants were asked to fill up the printed hand-outs of the questionnaire.

Ethical approval

The ethical committee clearance was not required for this study as the study involved only cadavers and not living individuals. The cadavers were sourced under the rules of the Anatomy Act, which allows the use of cadaveric material that is donated to the authorised teaching medical institution for therapeutic purposes or for the purpose of medical education and research, including anatomical examination and dissection.

Data collection and statistical analysis

For qualitative assessment of the haptic quality and the appearance of the cadaver, a Likert scale(1: strongly disagree, 2: disagree, 3: undecided, 4: agree and 5: strongly agree) was used. Other details pertaining to their surgical experience and previous exposure to learning using Genelyn®-embalmed cadavers were collected as yes/no questions. The quantitative variables were expressed either in a bivariate form(yes/no) or in measures for central tendency(median of Likert-scale responses). The median scores were analysed for the Likert’s scores of each parameter using Microsoft Office Excel 365 (Microsoft corporation, Redmond, Washington, USA).

RESULTS

Nineteen male surgeons participated in the workshop conducted using five Genelyn®-embalmed cadavers, with two cadavers as a backup. Of the 19 surgeons, majority were practicing GI surgeons(n=10) followed by surgeons from academic institutes(n=6, one additional professor, one associate professor and four assistant professors) and trainee surgeons(n=2). Most of the participants had >8years of surgical experience(n=11). Of the 19 surgeons, majority completed super-speciality course in surgical gastroenterology(n=13) followed by hepatobiliary surgery(n=2) and surgical oncology(n=2). The remaining two were general surgeons. Three in-house and two external GI surgeons were the resource persons for the workshop. Participants’ knowledge and prior experience with surgical skill training using cadaver are summarised in Table 1. Four participants had prior experience with training in cadavers, mostly formalin embalmed, for learning new surgical skills. The participants unanimously agreed that the Genelyn®-embalmed cadavers are a superior model for laparoscopic surgical skill training for GI procedures [Table 2]. Most of the participants(n=18) agreed that the Genelyn®-embalmed cadavers allow manipulation of tissues similar to that of live patients [Table 2]. Seventeen participants rated the workshop as excellent or good. Most of the participants(n=16, 84%) agreed that the appearance and tactile fidelity of the Genelyn®-embalmed cadavers were similar to those of live patients [Table 3].

Table 1

Participants’ knowledge and prior experience with cadaveric dissection for surgical skill training (n=19)

Question number	Question	Response, n
1	Do you consider that practicing surgical skills on the cadaver models should be mandatory before performing the laparoscopic surgeries in vivo?	Yes – 10No – 9
2	Prior to this workshop, have you attended any cadaver-based surgical skills workshops?	Yes – 4No – 15
3	If yes to the question number 2, what was the embalming method used in that workshop?	Formalin – 2Thiel’s – 1Genelyn® – 1
4	What were the surgical skills taught in that workshop that you attended in the past?	a) Open liver surgeries in formalin-embalmed cadaversb) Open surgical procedures in formalin-embalmed cadaversc) Laparoscopic procedures in formalin-embalmed cadavers

Table 2

Participants’ opinion on Genelyn®-embalmed cadavers used for laparoscopic surgical skill training (n=19)

Question number	Question	Response, n
		Yes	No
1	Have you ever worked with Genelyn®-embalmed cadavers?	1	18
2	Do you think that the consistency of the tissues in the Genelyn®-embalmed cadavers permits a realistic manipulation?	18	1
3	In the Genelyn®-embalmed cadaver, does the absence of bleeding reduce believability?	9	10
4	Do you consider that Genelyn®-embalmed cadaver is a better model for practicing laparoscopic GI surgery?	19	0
5	Do you consider whether practicing surgical skills in the Genelyn®-embalmed cadaver has been useful for you?	19	0
6	Do you consider whether Genelyn®-embalmed cadavers are superior to formalin-embalmed cadavers for use in surgical skill training workshops?	18	1

GI: Gastrointestinal

Table 3

Participants’ opinion regarding the general features of the Genelyn®-embalmed cadavers used for laparoscopic surgical skill training (n=19)

Indicators	Strongly disagree, n	Disagree, n	Undecided, n	Agree, n	Strongly agree, n	Median Likert score*
The cadaver tissue appears similar to live patient tissue (visual fidelity)	0	2	1	11	5	4
The cadaver tissue feels and dissects similar to live patient tissue (tactile fidelity)	0	2	1	12	4	4
The odour of the cadaver is unpleasant	6	9	3	1	0	2
The cadaver is suitable for surgical skills training	0	0	1	4	14	5

*Likert Score - 1: Strongly disagree, 2: Disagree, 3: Undecided, 4: Agree, 5: Strongly agree

The participants agreed in general that the colour, consistency and anatomical condition of the abdominal viscera were similar to invivo conditions [Table 4]. The participants observed that the colour of the stomach, spleen and pancreas was similar to in vivo conditions, whereas the consistency of spleen and pancreas in Genelyn®-embalmed cadavers more closely resembled that of live patients [Figures 1 and 2]. Most of the participants felt that the distensibility of the abdomen, the consistency of the fibrous tissue and the ability to stretch and manipulate the tissues were equivalent, meaning neither hard nor soft [Table 5]. Overall, the participants were satisfied with the laparoscopic training and strongly agreed that the workshop was useful to them [Table 6]. Qualitative comments from the participants regarding the workshop included increasing the duration of workshop time, provision of better scope and display unit, advanced table manipulation facility to simulate the scenario in the operation theatre and avoidance of obese cadavers for the workshop.

Table 4

Participants’ opinion regarding the appearance of each organ in Genelyn®-embalmed cadavers used for laparoscopic surgical skill training (n=19)

Indicators	Liver, gall bladder and bile duct (median score)	Appendix and intestines (median score)	Stomach (median score)	Spleen and pancreas (median score)	Colon (median score)	Blood vessels (median score)	Overall median Likert score*
Is the quality of organ colour in cadavers comparable to that of in vivo findings?	4	4	4	4	4	3	4
Is the quality of organ consistency of cadavers comparable to that of in vivo findings?	4	4	4	4	4	4	4
Is the anatomical condition on cadavers authentic and comparable to the in vivo findings?	4	4	4	4	4	4	4

*Likert score - 1: Too hard, 2: Moderately hard, 3: Equivalent, 4: Moderately soft, 5: Too soft

Figure 1

Photograph of the advanced laparoscopic surgical skills workshop

Figure 2

Laparoscopic view of the abdominal organs in Genelyn®-embalmed cadaver. (a) Colour and consistency of the transverse mesocolon, and the colon resembles tissues in live patients. (b) Ileocolic artery and vein dissected and isolated during laparoscopic right hemicolectomy. (c) Extravasated fluid accumulated in the dependent areas resembling blood gives a realistic feeling to the surgeon. (d) Tissue plane (marked as***) between mesocolic fascia and retroperitoneal fascia during mesocolic excision could be clearly demonstrated and small colic vessels (arrow) can be easily identified

Table 5

Participants’ opinion regarding the tissue pliability in Genelyn®-embalmed cadavers used for laparoscopic surgical skill training (n=19)

Tissue characteristics	Too hard, n	Moderately hard, n	Equivalent, n	Moderately soft, n	Too soft, n	Median Likert score*
Distensibility of the abdomen	4	8	5	2	0	2
Ability to stretch and manipulate the tissues	0	5	8	5	1	3
Consistency of fibrous tissue between the layers	0	3	9	7	0	3

*Likert score - 1: Too hard, 2: Moderately hard, 3: Equivalent, 4: Moderately soft, 5: Too soft

Table 6

Participants’ opinion regarding the laparoscopic surgical skill training workshop in Genelyn®-embalmed cadavers (n=19)

Indicators	Strongly disagree, n	Disagree, n	Undecided, n	Agree, n	Strongly agree, n	Median Likert score*
The workshop will help me to improve my laparoscopic skills	0	0	2	7	10	5
I am satisfied with the training	0	1	1	8	9	5
I will recommend the training to my peers	0	1	1	6	11	5

*Likert score - 1: Strongly disagree, 2: Disagree, 3: Undecided, 4: Agree, 5: Strongly agree

DISCUSSION

The present study is one of the first to evaluate the feasibility of using Genelyn®-embalmed cadavers in an advanced laparoscopic surgical skill training workshop for GI procedures. Furthermore, detailed feedback was obtained from the surgeons with prior experience in laparoscopic surgery. The results of the present study demonstrate that adequate pneumoperitoneum, a critical requirement for laparoscopic surgery, was achievable using Genelyn®-embalmed cadavers. The intra-abdominal solid viscera, including liver, gall bladder and luminal structures including stomach, small and large intestine, were easily identifiable. The bowel, mesentery and omentum were mobile and displaceable. All the loose areolar tissues and adipose tissues were well preserved. The participants appreciated the lifelike colour, consistency and tactile fidelity of the tissues. Three workshop participants with experience on formalin(n=2)-embalmed cadavers and Thiel’s(n=1) embalmed cadavers opined that the Genelyn® cadavers are lifelike with respect to the tissue planes, colour and tactile fidelity and are comparable to that of Thiel’s embalmed cadavers. There was a unanimous agreement that Genelyn®-embalmed cadavers permit realistic manipulation of tissues and are better than formalin-embalmed cadavers for surgical skill training.

Although any skill training model has its advantages and limitations, training using cadavers remains the most appropriate tool, especially for surgical skills. Human cadavers are indispensable resources for learning new surgical skills, given the shorter duration available for training in laparoscopic surgical procedures during the residency period.[11] Laparoscopy is increasingly used for GI surgeries as it is associated with lesser post-operative pain, shorter hospital stay and superior cosmetic outcome. Hence, it is imperative for surgeons to acquire laparoscopic surgical skills, and embalmed human cadavers serve as an ideal learning model.[12] Embalming is aimed at preserving human cadavers as lifelike as possible. Cadavers preserved using formalin offer excellent disinfection and complete preservation of the tissues. However, they are not suitable for learning laparoscopy as the tissues become rigid and lose the tactile fidelity.[13] Formalin embalming causes tissue hardening, loss of plasticity and discolouration of the tissues. In addition, laparoscopic training in formalin-embalmed human cadavers is not possible because of the inability to create a pneumoperitoneum.

Thiel’s embalmed cadavers are superior to formalin-embalmed cadavers for surgical skill training and are only ranked next to fresh frozen cadavers.[1415] In Thiel’s embalmed cadavers, the colour, consistency, plasticity and transparency of the tissues and range of joint movement are lifelike.[5] In addition, Thiel’s embalmed cadavers are odourless.[916] However, the cost per cadaver is high in Thiel’s embalming(1000 USD) compared to the Genelyn® embalming(200 USD).[16] Furthermore, Thiel’s embalming is an expensive and time-intensive method, which requires a minimum of 3 months of immersion in Thiel’s solution after Thiel’s arterial embalming.[17] Unlike Thiel’s, Genelyn® is a cost-effective alternative that requires no additional facilities apart from cold storage chambers. Genelyn® embalming is a comparatively faster technique and involves just the infusion of arterial fluid into the carotid arteries and drainage by internal jugular vein. The immersion of embalmed cadavers in a preservative solution is not required.

Ng et al., in a pilot study comparing raising of the microvascular flap in formalin-embalmed cadaver and Genelyn® cadaver, reported that the ease of identification of different tissues and the colour and lifelike pliability of organs were superior with Genelyn®-embalmed cadavers.[18] However, some studies reported Genelyn® as a hard fixative producing pale-coloured tissues with rigid consistency, resulting in difficult identification of surgical planes.[9192021] Balta et al. reported Genelyn® as a hard fixative by studying only the range of joint movements without dissecting the cadavers to see tissue pliability, separation of tissue planes and tissue colour.[2021] Jaung et al. compared three embalming solutions: Graz fluid(Thiel’s): one cadaver, Dodge fluid: four cadavers and Genelyn®: five cadavers with fresh frozen cadavers.[9] They reported that Graz fluid(Thiel’s) fared well, followed by Genelyn® and Dodge fluid in the parameters such as joint flexibility, tissue pliability, fungicidal properties and lifelike tissue colour. However, none of the embalming fluids could match the parameters of the fresh frozen cadaver. The drawback of their study is the authors just observed the tissues by gross dissection of the anterolateral chest wall to measure tissue pliability and lifelike tissue colour and did not assess the utility of Genelyn® cadavers for laparoscopic training. In the present study, the colour and consistency of organs in Genelyn®-embalmed cadavers were lifelike with supple and pliable tissue permitting easy identification and separation of different tissue planes during laparoscopic surgery. The reasons for inferior tissue preservation reported in some studies could be delay in shifting the cadaver organ into the cold storage, resulting in decomposition. Furthermore, cadavers should be embalmed using Genelyn® after adequate thawing. The thawing time varies between different climate zones and the built of the cadavers.

Jaung et al. reported that Genelyn®-embalmed cadavers might be susceptible to fungal mould growth.[9] However, whether samples to determine mould growth were collected immediately after embalming or after a certain period was not documented. Furthermore, the decomposed body used in the study is prone to mould growth. Balta et al. studied the presence of fungal moulds in Genelyn®-embalmed cadavers and reported that the Genelyn®-embalmed cadavers were mould free immediately after the embalming.[22] In addition, certain regions were mould free for a certain amount of time after embalming namely, the axillary region for 8 months, the inguinal region for >8 months and the internal organs for >8 months. In the present study, the Genelyn®-embalmed cadavers were used for the workshop within 5 months, and we did not observe any visible moulds on the exterior of the cadaver or within the abdominal cavity when visualised during laparoscopy. Furthermore, we have utilised the same Genelyn®-embalmed cadavers for another workshop in general surgery(neck surgeries) after 6 months and plastic surgery(brachial plexus and major flaps) after 8 months of embalming, and we have not noticed any visible growth of moulds either on the exterior of the cadaver or in the thoracic and abdominal cavities, which were explored during plastic surgery workshop for tissue assessment. Although we did not conduct a microbiological evaluation for fungal moulds, we can reasonably conclude that the Genelyn®-embalmed cadavers are not susceptible to mould at least 6–8 months after embalming and can be reused.

From our experience in embalming, we observed that factors such as the cause of death, time delay between death and the preservation of the body, inadequate thawing after cold storage, embalming during rigor mortis, excess arterial perfusion of tissues by embalming solution without drainage, inappropriate constitution and dilution of the embalming solution(Genelyn®) and excessive injection pressure may affect the tissue consistency of the embalmed cadaver. Ideally, the time interval between the death and embalming should be within 6 h of death, without cold storage, and within 24 h after death, with cold storage. The optimal injection pressure and the amount of arterial solution perfused might have contributed to better results in the present study compared to that of previous Genelyn®-embalmed cadaver studies.

We have analysed the workshop participants’ subjective perception of various parameters during advanced surgical skill training in Genelyn®-embalmed cadavers. While the small sample size is a limitation of the present study, studies comparing different embalming solutions typically use a sample size of 2–5 cadavers per each study group. Furthermore, the stringent cadaver criteria limit the number of eligible cadavers suitable for laparoscopy training. Another limitation of the present study is the lack of comparison of Genelyn®-embalmed cadavers with other techniques. A comparative objective evaluation of parameters such as distensibility of anterior abdominal wall, tissue pliability, ability to separate tissue planes, displaceability of the small and large bowel and lifelike tissue colour as observed during laparoscopy among cadavers embalmed using different embalming techniques will add more information to the knowledge database of Genelyn®.

CONCLUSION

The findings of the current study based on the feedback from surgical skill training workshop participants using a validated questionnaire suggest that the Genelyn®-embalmed human cadavers are effective teaching tools for training advanced laparoscopic surgical skills in GI surgery.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.