Surgical skills training for VATS: lobectomy and anatomical segmentectomy on soft-embalmed human cadavers according to Thiel and Dodge—a first pilot study

Introduction

Background

Video-assisted thoracic surgery (VATS) has transformed thoracic surgery, becoming an integral part of minimally invasive thoracic surgical procedures. This approach, which utilizes small incisions and a video camera rather than traditional open surgery techniques, has garnered significant interest due to its ability to reduce patient morbidity, enhance recovery times, and optimize surgical outcomes (1-3).

Effective training methods in VATS are particularly important for novice surgeons, as surgical competence directly impacts patient outcomes (4,5). Traditional teaching methods have increasingly integrated soft-embalmed human cadavers into training programs not only for novice surgeons and have been shown to be useful for senior surgeons (6-8). The experience gained from cadaver-based training has been shown to significantly improve technical skills and confidence, resulting in enhanced competence when transitioning to live patients or high-fidelity simulators (9,10). Studies have indicated that cadaver-based workshops enhance experiential learning and foster a deeper understanding of the surgical principles and anatomy necessary for mastering VATS techniques (11-13).

Rationale and knowledge gap

Soft-embalmed cadavers, according to Thiel’s method (14,15), offer advantages over traditional formalin-preserved specimens used in anatomical dissection rooms. Thiel-embalmed cadavers (TeCs) have been demonstrated to improve better preservation of tissue texture and color, enabling high flexibility of cadavers, supporting a lifelike learning setting (16,17). Soft-embalmed cadavers using the Dodge technique (Dodge Solutions, Dodge Co., Billerica, MA, USA) are also characterized by their remarkable realism with color fidelity of fresh tissue and notable flexibility (18,19).

Surgical training on TeCs is an effective and realistic option for practicing advanced surgical techniques, as demonstrated in prior studies (6,7,20-22). To the best of our knowledge, there have been only a limited number of studies published regarding the use of Dodge embalmed cadavers (DeCs) in surgical training (7,8,19,22). The use of DeCs in VATS has not been reported up to now.

Objective

This retrospective cross-sectional study aims to present a descriptive report of our findings with an initial pilot study using soft-embalmed cadavers according to the methods of Thiel and Dodge for surgical training in VATS. A particular focus was placed on feedback from the participants in relation to the realism of surgical training on soft-embalmed cadavers compared to living patients.

Methods

Soft-embalmed human cadavers

A total of five cadavers were available for VATS training. Three cadavers underwent embalming using the Thiel method (14,15), while two others were embalmed following the Dodge technique.

The cadavers were provided by the Department of Anatomy at Gutenberg University of Mainz (TeCs) and the non-profit organization MoViDo gGmbH based in Essen, Germany (DeCs). Following the completion of the embalming process, TeCs and DeCs were moved to the University of Witten/Herdecke for scientific examinations.

All human cadavers were used in accordance with the stringent guidelines of donation programs. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of the University of Witten/Herdecke (21.10.2024/No. S-281/2024). Human cadavers were obtained through the institutional body donation program with prior consent.

Cadaver selection

Cadavers were chosen based on the condition of the surgical area to ensure there had been no prior lung surgeries. Therefore, the selection process involved exclusion of surgical scars from the chest. Sex selection was randomized. Owing to data protection regulations for body donation, no additional information about the cadavers’ previous illnesses or surgeries could be obtained. During the training process, previous surgical interventions in the lungs were excluded at the macroscopic level.

Trainee selection

Aspirants for participation were requested to submit information about their prior surgical experience and current position. The cohort of the trainees included three specialists and seven senior physicians. Having a desired or current focus in VATS was a requirement for consideration.

General logistics

The training was organized as a one-and-a-half-day workshop, including a half-day lecture and a full day of hands-on training. Ten participants performed uniportal or multiportal VATS on five soft-embalmed cadavers under the supervision of five board-certified thoracic surgeons as VATS experts and one expert in clinical anatomy.

Each VATS expert guided a team of two trainees. The teams operated on either a TeC or DeC. The setting was designed to resemble an operating room, including the original surgical equipment such as instruments for minimally invasive thoracoscopy, lung staplers, sutures, and other surgical supplies. The purpose of the workshop was to offer novice surgeons exceptional practical experience with human cadavers, utilizing the soft-embalming techniques established by Thiel and Dodge.

Surgical logistics

The training took place in the dissection hall at the Anatomical Institute of Witten/Herdecke University. Anatomical tables were utilized as operating tables. These could not be adjusted, raised, lowered, or tilted. The cadavers were manually positioned in the lateral decubitus position for anterolateral thoracotomy. A semicircular neck holder was placed below the thoracoabdominal transition site to ensure optimal situs exposure. In addition to the endoscopic systems and staplers, the original surgical instruments for thoracotomy and thoracoscopy were used. For the thoracotomy part, 360° atraumatic circumferential wound protector retractors were utilized for an optimal overview of the situs. Figures 1,2 show the settings during training on TeC and DeC.

Figure 1 Setting during VATS training showing trainees performing on Thiel embalmed cadaver. This image is published with the participants’ consent. VATS, video-assisted thoracic surgery.

Figure 2 Trainees during VATS training on Dodge embalmed cadaver. This image is published with the participants’ consent. VATS, video-assisted thoracic surgery.

Surgical technique

The lectures were completed on day one. On day two, hands-on training was performed on the soft-embalmed cadavers. Video-assisted lobectomy and anatomical segmentectomy are considered standard procedures in minimally invasive tumor surgery for bronchial carcinomas and were therefore selected as procedures for practical VATS training. Each trainee performed upper lobe lobectomy and anatomical segmentectomy. Both surgical procedures were performed in adherence with regular surgical practices conducted on living patients. The surgical procedures were completed by the trainees on their own under the guidance and supervision of an expert. The roles of the surgeon and first assistant were alternated by the trainees. The first trainee performed surgical procedures on the right lung. Once completed, the cadaver was turned onto its right side, and the second trainee performed surgical procedures on the left lung.

Evaluation

The structured questionnaire developed in this study was formulated according to the model by Jaeger et al. (6,8). The questionnaire was based on the training procedures conducted for the VATS workshop. It was developed in collaboration with the workshop leader, a board-certified thoracic surgeon [Fellow of the American College of Surgeons (FACS), Fellow of the Royal College of Physicians (FRCP)], with over 15 years of professional experience.

The questionnaire aimed to examine the essential surgical steps of lobectomy and anatomical segmentectomy in terms of their realism in relation to surgery on living patients. Trainees and experts were asked to provide anonymous subjective feedback on nineteen questions. The questions were rated on a 5-point Likert scale, ranging from 1 (“strongly disagree”) to 5 (“strongly agree”). The questionnaire contained a section with general questions according to Jaeger et al. (8) (Module G) about the training experience (e.g., general realism of the training, recommendation) and specific questions with modules A-C about the main surgical steps in lobectomy and segmentectomy, including the feasibility and realism of the surgery on soft-embalmed cadavers. The questionnaire, which included all general and specific questions, is presented in Table 1. The evaluation did not incorporate any measures to ascertain the effectiveness of the surgical skills training imparted during the class.

Table 1 provides an overview of the questionnaire.

Statistical analysis

The evaluation results of the questionnaires according to the Likert scale (1 to 5) were analyzed using the software “R” (R Foundation for Statistical Computing, Version 4.3.1, 2023) and presented using medians.

Results

Participation in the evaluation process was voluntary. Fourteen questionnaires were used in the analysis. Five questionnaires were completed by VATS experts and nine questionnaires were completed by trainees. One trainee was unable to participate in the evaluation due to scheduling conflicts. The evaluation results refer to the trainees and experts. A distinction was made between the evaluation results for TeCs and DeCs.

General questions—training experience

In the general questions (Figure 3, Module G) the participants recommended the performed hands-on training on soft-embalmed cadavers (G4) with a median of 5 (totally agree) in both groups, DeCs and TeCs.

Figure 3 General questions—training experience, Module G.

The training on the soft-embalmed cadavers was rated as realistic [G3, median =4 (agree) for TeCs; median =4/5 (agree or totally agree) for DeCs] and as a good preparation for surgery on a live patient [G1, median =4/5 (agree or totally agree) for TeCs; median =5 (totally agree) for DeCs]. The question of whether training under supervision could make inexperienced surgeons more confident in performing the operations (G2) was rated with a median of 4 (agree) for TeCs and a median of 5 (totally agree) for DeCs.

Specific questions—lobectomy and anatomical segmentectomy

Module A—surgical access

In Module A (Figure 4), specific questions regarding the realism of surgical access for thoracotomy were evaluated. The realism of the skin incision was rated with a median of 5 (totally agree) for both, TeCs and DeCs, and the preparation of the tissue for the thoracotomy was rated with a median of 4/5 (agree/totally agree) for both, TeCs and DeCs.

Figure 4 Specific questions—lobectomy and anatomical segmentectomy, Module A. Module A: surgical access/thoracotomy.

Module B 1–3—hilus dissection—vein, artery and bronchus

In module B 1–3 (Figure 5-7), all specific questions about the realism of hilus dissection and the anatomical detection and preparation of the vein, artery, and bronchus were rated with a median of 4 or better (agree or totally agree) for both embalming methods, TeCs, and DeCs. The results are shown in Figures 5-7.

Figure 5 Specific questions—lobectomy and anatomical segmentectomy, Module B1. Module B1: hilus dissection—vein.

Figure 6 Specific questions—lobectomy and anatomical segmentectomy, Module B2. Module B2: hilus dissection—artery.

Figure 7 Specific questions—lobectomy and anatomical segmentectomy, Module B3. Module B3: hilus dissection—bronchus.

Module C—Cutting the parenchyma

In module C (Figure 8), all specific questions about the realism of cutting the parenchyma were rated with a median score of 4 or better (agree or totally agree) for TeCs and DeCs.

Figure 8 Specific questions—lobectomy and anatomical segmentectomy, Module C. Module C: cutting the parenchyma.

The inspection reveals clearly recognizable tissue layers for layer-appropriate preparation (C1, median =4/5 (agree/totally agree), for TeCs and DeCs) and the tissue layers could be easily moved against each other (C3, median =4/5 (agree/totally agree), for TeCs and DeCs). The tissue was rated as soft and elasticated (C2), with a median of 5 (totally agree) for TeCs and a median of 4 (agree) for DeCs. Tissue preparation offers a realistic surgical experience (C4), with a median of 4 for TeCs (agree) and a median of 4/5 for DeCs (agree/totally agree).

Discussion

Key findings

The present study introduces a novel method for VATS training using soft-embalmed cadavers according to Thiel and Dodge. The evaluation results, as rated by the participants, demonstrated a high degree of realism in comparison to surgery on living patients, confirming a realistic anatomical orientation and tissue characteristics for TeCs and DeCs. All specific aspects of the surgical procedure, such as surgical access for thoracostomy, hilar dissection, and preparation of the tissue, were assessed as realistic for both soft-embalming methods, Thiel and Dodge. However, this pilot study had certain limitations.

Strengths and limitations

First, the insights provided by the trainees and experts are useful for the initial reports of surgical training in VATS on soft-embalmed cadavers, according to Thiel and Dodge. However, it was based on the subjective experiences of the participants. Future studies should include a larger number of cases to ensure the credibility and generalizability of the findings. These additional cases could facilitate extended statistical analyses and verify the results of the present study.

Second, the present study did not incorporate objective metrics to assess the efficacy of skills training imparted during supervised teaching on cadavers. The implementation of before and after teaching tests or the utilization of a reference group (e.g., simulator, synthetic model, cadavers) has the potential to enhance the objectivity of the findings and educational significance. The transfer of newly acquired skills to living patients could be investigated in a follow-up study and provide valuable insights into the overall concept of surgical training.

Third, the questionnaire was predefined based on participants’ impressions of the training. Consequently, it is reasonable to hypothesize that other factors that influence participants’ impressions may be undetected. The incorporation of supplementary remarks, open-ended inquiries, or a separate module comprising interviews, has the potential to reveal previously unconsidered aspects.

Another critical aspect to consider is potential variability among cadavers. Despite adherence to the standard protocol for embalming, individual differences between cadavers can lead to variations in embalming quality itself. Finally, the choice of the embalming method (e.g., Thiel or Dodge) is also of consequence, as it can lead to disparities in the quality of the tissue of the organs (e.g., color, flexibility, soft/hard).

Comparison with similar research

VATS has become an essential component of minimally invasive thoracic surgeries, due to its capacity to accelerate recovery times and reduce patient morbidity (1-3). Research indicates that cadaver-based workshops improve the understanding of the specific anatomy and essential surgical principles in VATS (11-13). Nevertheless, effective and realistic training methods are of particular importance for novice surgeons as surgical competence directly affects patient outcomes (4,5). Conventional surgical training methods increasingly incorporate embalmed human cadavers into the educational concepts for novice surgeons in several surgical disciplines (6-8,20-22), including urology, general surgery, gynecology, and many others. Technical skills and confidence have been shown to be significantly improved through cadaver-based training, resulting in enhanced competence when transitioning to live patients or high-fidelity simulators (9,10).

Although traditional educational methods and high-fidelity simulators have their own benefits, cadavers provide trainees with a distinct advantage in terms of tactile feedback and realistic handling of tissues (9,23). Furthermore, the cadaver model has been identified as a superior anatomical simulator compared to high-fidelity virtual reality systems (11,12). Additionally, soft-embalmed cadavers maintain a similarity to living tissues, thereby enabling the training of essential surgical skills in a controlled setting (11,12).

Explanations of findings

The present study presents the evaluation results of subjective feedback from VATS training on Thiel and Dodge cadavers. The use of Dodge cadavers for VATS training is a novelty and represents a first pilot report. Participants rated the training for both Thiel and Dodge as realistic compared to operating on living patients and recommended VATS training on TeCs and DeCs. The feedback collected was of a subjective nature. Objective measures were not used in the current study.

However, the findings provide an encouraging new approach to surgical education for VATS procedures, offering a promising method for training in both embalming techniques.

Implications and actions needed

The stated limitations of the study have the potential to exert a substantial influence on participants’ perceptions of the realism of the cadaveric training experience. Therefore, it is essential that these aspects be incorporated into the questionnaire in future studies. A subsequent step is a thorough, systematic comparison of Thiel’s and Dodge’s soft-embalming methods. In this case, a comprehensive analysis should consider factors such as the local availability of soft-embalmed cadavers, cost-effectiveness, preservation period, and other factors.

The implementation of TeCs and DeCs in conventional training programs as a realistic training method for VATS is conceivable.

Conclusions

In conclusion, the implementation of VATS training on soft-embalmed human cadavers represents a promising method in surgical education. It provides a realistic anatomical training of VATS to prepare trainees for clinical practice and underpins the ongoing evolution of surgical methodologies aimed at improving patient safety and outcomes.

According to the participants of the VATS study, surgical training on soft-embalmed human cadavers according to Thiel and Dodge received a high level of recommendation. The evaluation results demonstrated a remarkable degree of realism in both embalming techniques when compared to surgical procedures performed on living patients. Significant results require confirmation by further studies with larger sample sizes.

Acknowledgments

The authors sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially increase mankind’s overall knowledge which can then improve patient care. Therefore, these donors and their families deserve our highest gratitude.

The authors thank the Institute of Anatomy at the University Medical Center of Johannes Gutenberg-University Mainz and the non-profit prosecture MoViDo gGmbH for supporting postgraduate training by providing human cadavers for surgical education.

Footnote

Data Sharing Statement: Available at https://vats.amegroups.com/article/view/10.21037/vats-25-38/dss

Peer Review File: Available at https://vats.amegroups.com/article/view/10.21037/vats-25-38/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://vats.amegroups.com/article/view/10.21037/vats-25-38/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of the University of Witten/Herdecke (21.10.2024/No. S-281/2024). Human cadavers were obtained through the institutional body donation program with prior consent.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Klapper J, D'Amico TA. VATS versus open surgery for lung cancer resection: moving toward a minimally invasive approach. J Natl Compr Canc Netw 2015;13:162-4. [Crossref] [PubMed]
2. Wang Z, Pang L, Tang J, et al. Video-assisted thoracoscopic surgery versus muscle-sparing thoracotomy for non-small cell lung cancer: a systematic review and meta-analysis. BMC Surg 2019;19:144. [Crossref] [PubMed]
3. Zhao H, Bu L, Yang F, et al. Video-assisted thoracoscopic surgery lobectomy for lung cancer: the learning curve. World J Surg 2010;34:2368-72. [Crossref] [PubMed]
4. Asbjornsson V, Johannsdottir G, Myer D, et al. A successful shift from thoracotomy to video-assisted thoracoscopic lobectomy for non-small cell lung cancer in a low-volume center. Interdiscip Cardiovasc Thorac Surg 2024;38:ivae018. [Crossref] [PubMed]
5. Abdel Jalil R, Abou Chaar MK, Al-Qudah O, et al. Early surgical and oncological outcomes during adoption of a single port VATS lung resection in a tertiary cancer center: a retrospective analysis. J Cardiothorac Surg 2022;17:26. [Crossref] [PubMed]
6. Jaeger D, Maghaireh O, Shaleva A, et al. Surgical cystectomy training using human cadavers embalmed using Thiel's method: a pilot study. BJU Int 2024;134:834-40. [Crossref] [PubMed]
7. Jaeger D, Hinrichs E, Eichbaum M, et al. Surgical training in gynecological oncology using soft-embalmed human cadavers: first pilot study. Arch Gynecol Obstet 2025;312:473-85. [Crossref] [PubMed]
8. Jaeger D, Hinrichs E, Schoppe R, et al. Pancreaticoduodenectomy on soft-embalmed human cadavers according to Dodge - a pilot feasibility report. Surg Open Sci 2025;26:107-12. [Crossref] [PubMed]
9. Takayesu JK, Peak D, Stearns D. Cadaver-based training is superior to simulation training for cricothyrotomy and tube thoracostomy. Intern Emerg Med 2017;12:99-102. [Crossref] [PubMed]
10. Abraham J. Practicing on Newly Dead. SAGE Open 2015;5:215824401559527.
11. Sharma M, Horgan A. Comparison of fresh-frozen cadaver and high-fidelity virtual reality simulator as methods of laparoscopic training. World J Surg 2012;36:1732-7. [Crossref] [PubMed]
12. Gilbody J, Prasthofer AW, Ho K, et al. The use and effectiveness of cadaveric workshops in higher surgical training: a systematic review. Ann R Coll Surg Engl 2011;93:347-52. [Crossref] [PubMed]
13. Nesbitt CI, Tingle SJ, Williams R, et al. Educational Impact of a Pulsatile Human Cadaver Circulation Model for Endovascular Training. Eur J Vasc Endovasc Surg 2019;58:602-8. [Crossref] [PubMed]
14. Thiel W. An arterial substance for subsequent injection during the preservation of the whole corpse. Ann Anat 1992;174:197-200.
15. Thiel W. Ergänzung für die Konservierung ganzer Leichen nach W. Thiel. Ann Anat 2002;184:267-9. [Crossref] [PubMed]
16. Barton DP, Davies DC, Mahadevan V, et al. Dissection of soft-preserved cadavers in the training of gynaecological oncologists: report of the first UK workshop. Gynecol Oncol 2009;113:352-6. [Crossref] [PubMed]
17. Villacorta P, Hernando H, Abdulla A, et al. A Comparative Study of Thiel Soft-embalmed and Formalin Preserved Cadavers for Anatomy Dissection. Acta Medica Philippina 2019;53:12-20.
18. Thompson B, Green E, Scotcher K, et al. A Novel Cadaveric Embalming Technique for Enhancing Visualisation of Human Anatomy. Adv Exp Med Biol 2022;1356:299-317. [Crossref] [PubMed]
19. Jaung R, Cook P, Blyth P. A comparison of embalming fluids for use in surgical workshops. Clin Anat 2011;24:155-61. [Crossref] [PubMed]
20. Usami T, Fujioka T, Yoshida A, et al. Assessment of laparoscopic training for gynecological malignancies using Thiel-embalmed human cadavers. Mol Clin Oncol 2018;9:511-4. [Crossref] [PubMed]
21. Yiasemidou M, Roberts D, Glassman D, et al. A Multispecialty Evaluation of Thiel Cadavers for Surgical Training. World J Surg 2017;41:1201-7. [Crossref] [PubMed]
22. Jaeger D, Hinrichs E, Kösek V, et al. Training of tube thoracostomy on soft embalmed cadavers according to Thiel and Dodge - what do experts say? Ann Thorac Surg Short Rep 2025;3:1161-5. [Crossref] [PubMed]
23. Chandran R, Koo SH, Lim YY, et al. Enhanced Experiential Learning in Airway Management: Surgical Modification of Cadavers. Simul Healthc 2021;16:142-50. [Crossref] [PubMed]