SciELO - Scientific Electronic Library Online

vol.27 número1Preenchimento de alvéolos dentais de gatos com osso autógeno índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados




Links relacionados


Acta Cirurgica Brasileira

versão On-line ISSN 1678-2674

Acta Cir. Bras. vol.27 no.1 São Paulo jan. 2012 



Organic bench model to complement the teaching and learning on basic surgical skills1


Modelo de bancada orgânico para complementar o ensino-aprendizagem de habilidades cirúrgicas básicas



Rafael DenadaiI; Luís Ricardo Martinhão SoutoII

IGraduate student, School of Medical Sciences, UNIMAR, Marilia-SP, Brazil. Conception, design, intellectual and scientific content of the study; involved in technical procedures; collection of study informations and manuscript writing
IIPhD, Assistant Professor, Division of Plastic Surgery, Department of Surgery, School of Medical Sciences, UNIMAR, Marilia-SP, Brazil. Supervised all phases of the study; conception, design, intellectual and scientific content of the study; involved in technical procedures; manuscript writing and critical revision





PURPOSE: To propose an organic bench model made with fruits/vegetables as an alternative to complement the arsenal of simulators used in the teaching and learning of basic surgical skills during medical graduation and education.
METHODS: They were described the training strategies, through the use of fruits (or vegetables) to the learning of different techniques of incision, sutures, biopsies and basic principles of reconstruction. The preparation of bench model, the processes of skill acquisition, feedback and evaluation were also delineated.
RESULTS: A proposal for teaching based on an organic model with training delivered in multiple sessions, with increasing levels of difficulty, and with feedback and evaluation during all the process was structured.
CONCLUSION: The organic model, being simple, versatile, portable, reproducible, readily available, and having low cost, is another option to complement the existing simulators for teaching and learning of basic surgical skills.

Key words: Surgery. Education. Teaching Materials. Models, Educational. Learning. Training.


OBJETIVO: Propor um modelo de bancada orgânico, confeccionado com legumes/frutas, como alternativa para complementar o arsenal de simuladores aplicados no ensino-aprendizagem das competências cirúrgicas básicas durante a graduação e o ensino médico.
MÉTODOS: Foram descritas as estratégias de treinamento, através da utilização de frutas (ou legumes), para a aprendizagem de diferentes técnicas de incisão, suturas, biópsias e princípios básicos de reconstrução. A preparação do modelo de bancada, os processos de aquisição de habilidades e feedback e os métodos deavaliação também foram delineados.
RESULTADOS: Estruturou-se uma proposta de ensino baseada em um modelo orgânico com o treinamento distribuído em várias sessões, com níveis crescentes de dificuldade e com feedback e avaliação de todo o processo.
CONCLUSÃO: O modelo orgânico, por ser simples, versátil, portátil, reprodutível, disponível, de fácil aquisição e baixo custo é mais uma opção para complementar o arsenal de simuladores de ensino e aprendizagem existentes.

Descritores: Cirurgia. Educação. Materiais de Ensino. Modelos Educacionais. Aprendizagem. Capacitação.




Based on the assumption that general practitioners are routinely faced with situations that require implementation of ambulatory surgical procedures1,2, and that most physicians do not get satisfactory surgical skills during their academic training3, it is necessary to establish a training program aimed at the teaching and improving of these technical skills to undergraduates and newly graduates1,2. Although different simulators have been described to provide this training4, none of them is complete.

In an attempt to find a simulator that presents minimum requirements for storage and that can be easily discarded, one that is simple, versatile, portable, reproducible, affordable, easy to acquire, with a low financial cost, and that permits the evaluation of practice with feedback for improving the skills/surgical technique, this study proposes the use of an organic bench model made with vegetables/fruits for teaching-learning during medical school, as a complementary alternative to the existing bench simulators.

Teaching-learning with the organic bench model for the training of basic surgical skills

The organic model can be used for training medical students who never had contact with basic surgical skills and for those who had some contact with these skills but need to improve the learned technique.

The purpose of this model is based on the teaching during several training sessions (days or weeks), interspersed with periods of rest, which can be adapted and distributed in a way that complements the curriculum already established and that can be applied in the context of the disciplines of operative technique, clinical surgery, plastic surgery, and others.

In classrooms, a group of four students should train under the direct supervision of an instructor (according to previously described by Dubrowski and MacRae5) and they should be encouraged to practice and refine skills at home, later bringing the model with the performed procedures for evaluation with feedback. Instructors can be faculty physicians or nonphysicians, such as laboratory technicians, surgical technicians or students who can master the technique (monitoring format); these nonphysician surgical skills coaches should be trained by a faculty surgeon to administer teaching and practice sessions.

It is important to set teaching goals in an increasing order of difficulty, which must be distributed at the sessions. The basic structure of each session is a brief talk with pictures and videos-classes on the proposals of the day, followed by training. Additional explanations can be made during practice. Initially, the procedures can be demonstrated by the instructors to the student group. After that, specific points of the techniques can be addressed individually.

Training should be directed to the student. In the beginning of the process, the goals can be similar for all group members. However, in subsequent sessions, the proposals can vary according to the differences in the acquirement of students' abilities. As the student acquires simpler skills, the degree of difficulty should be increased.

The basic objectives proposed and described in this study include handling of surgical instruments, training of suture techniques, incisions, surgical resection with or without safety margins and incisional/excisional biopsies, and basic principles of reconstruction, such as "grafts".

Making an organic bench model

To make the model, it is only needed to have the chosen fruit (or vegetable), a plate of Styrofoam, needles (size and quantity vary according to fruit or vegetable) and a ballpoint pen or marker. For the chosen fruit (or vegetable) not sip during training, it should be fixed in the Styrofoam with needles. It is also needed No. 15 blade and No. 3 scalpel cable, anatomic and tooth rat tweezers, Mayo scissors, needled threads and Mayo-Hegar needle holder (Figure 1).



The fruits (or vegetables) are acquired in commercial establishments, and preference should be given to those which have thicker peels and are not softened. The choice of a specific fruit or vegetable is variable. For training of sutures it is preferable to use orange, lemon or eggplant. Lemon presents the risk of staining the skin if there is exposure to sunlight after contact. On the acquirement of skills such as removal of debris in spindles and "skin" biopsies, it is preferable to use banana, lemon or orange. Differences in costs and seasonal availability of products may also affect the choice.

Training incisions and sutures

Incisions and sutures can be trained concurrently. For this, students make a mark on the peel of the fruit or vegetable, and then make the incision in the previous mark, simulating an injury and using the taught technique. Then, sutures are made to close the edges of the incised area, also applying the teachings about the technique. Different incisions (linear, circular, vertical and horizontal) and sutures (single interrupted sutures, vertical mattress suture according to Donati and McMillen, modified vertical mattress suture according to Allgöwer, horizontal mattress suture, running simple suture and running locked suture) (Figure 2) can be trained.



Training of basic surgical techniques for the handling of "skin lesions"

The simulation of different skin lesions, through drawings on peels of the chosen model, for students to make their respective diagnoses and/or treatment and repairs, makes the surgical training (resections with and without safety margins, incisional/excisional biopsies, and grafts of "skin") more attractive and rewarding (Figure 3). Each of these procedures should be taught separately to the student, so that he can learn about every technique in details.



For example, by simulating a non-melanoma skin cancer, the student should do the marking of safety margins, the incision in the margins, the removal of the surgical piece and the correction of the defect with the graft or flap advancement/rotation (Figure 4).



Feedback and evaluation

Feedback and evaluation are important to improve the learning of each taught technique. Feedback should be performed during and after each stage of training in the classroom, or at specific times scheduled after the training at home, in which the student will improve the taught fundamentals on his own. Instructors must evaluate each motion, searching for specific items that are not being adequately carried out (errors and failures) so that they provide a constructive feedback to students, enabling them to learn from their mistakes and as a result they can acquire skills over time. The marking lines can serve as an evaluation parameter; one should point out and correct incisions outside them. Regardless of the feedback, it is important to encourage students to clear up their doubts during training and after completion of extracurricular tasks.

The Global Rating Scale6, which assesses students during performance of tasks in eight main areas (Table 1), can be used to evaluate and monitor the gain of students' abilities; each area presents a five-point scale (one corresponds to a minimum score and five corresponds to a maximum score), with a maximum total score of 40. Instructors can apply this scale at the end of each teaching session and in subsequent sessions they can follow the acquirement of students' skills and the specific points, among the eight evaluated ones, that deserve greater attention. The assessment can also be used to ensure that most students have trained and understood the proposed techniques. For an individual task, the candidate must achieve a score of 24 or more to be considered competent7.



Although the acquisition of basic techniques and surgical skills have been only a part of the surgical learning, such knowledge is relevant to the general practitioners because it has important implications in the care of patients. Despite the importance of the topic, these skills are not acquired by a large percentage of students during their training3.

Since nowadays the traditional method of training based on practice with patients violates ethical and medico-legal issues8, there are simulation laboratories aimed at providing training techniques and surgical skills; these should be integrated into the educational program4,9 and have clearly defined learning goals9.

As was demonstrated that the training of novices in surgical skills laboratories can leads to improved technical performance during periods of increased attention demands10 and that the training in basic skills can lead to better performance of more complex tasks11, students should practice in increasing levels of difficulty, from an individual9, deliberate, repetitive, and participatory basis, rather than learning only by observation12. The improvement of the technique is also possible based on performance errors13 without the worry of harming the patient14.

In these learning scenarios, there is a variety of simulators that must be seen as complementary tools since they provide the training and accelerate the learning curve of practical surgical skills, enabling a better use in further contact with patients; this contact represents the cornerstone of medical teaching4.

The available simulators vary with regard to the level of fidelity (realism) when compared with a live human4. The higher fidelity models, such as human cadavers, discarded surgical specimens in surgical procedures, postmortem and live animals, and virtual reality simulators, are more attractive to the trainees4. However, during the training of surgical skills with beginner students, it was demonstrated that the transfer of skills to the clinical environment is independent of fidelity15. Thus, low-fidelity models can reduce costs and provide more material and training opportunities without jeopardizing the results12,15.

Because of the ethical/legal problems, the financial impact and the access difficulties inherent to training on human cadavers, live laboratory animals and virtual reality simulators, numerous bench models have been described as options for the training of surgical techniques4. Based on this, the main focus of this study is to propose the use of a bench model made of organic fruits or vegetables as a complementary alternative to teaching and learning; this model is accessible, portable, reproducible and of low cost and it can be used to complement the teaching of the surgery basis during medical education.

Similar organic models, with different indications, were described previously; they were made with oranges to the learning of skills in plastic surgery and debridement of necrotic ulcers, and with bananas, tomatoes and melons for the training of Mohs micrographic surgery and biopsy16-20. The bench model and its proposed form of use in this study provide the teaching-learning for beginners in surgical techniques training and, as students acquire the pre-set requirements (simple skills), training can be enhanced with the teaching of more complex procedures in the model itself or in other simulators.

Backstage models and latex gloves are also reproducible, they are readily available and are inexpensive; therefore, they do not allow the training of procedures such as excisions and three-dimensional reconstructions. Synthetic materials such as polyurethane21 (Allevyn®), microfoam tape7 (3M®) and latex skin pad7 (Limbs & Things®) enable the training of these procedures; however, not in three-dimensional plane and they are difficult to acquire compared to vegetables and fruits.

The training of some surgical techniques could be carried out on models such as discarded surgical specimens22 or postmortem animals4. However, for the use of human organs, donation is required by the consent of patients and/or family, and also the existence of a collection/storage service in the institution itself. The postmortem animals need adequate facilities for storage and disposal, which often complicates and impedes training. There are also risks of infection in both cases (human organs and postmortem animal).

Nevertheless, the proposed bench model should not necessarily replace the teaching simulators used in different educational institutions. Indeed, the proposal is that it is complementary or adapted to the existing teaching. Some fruits (lemon, orange and banana), besides the three-dimensional spatial concept, allow students to have an idea of different layers and, even though being of low fidelity, they can mimic human skin – for example, the colored surface of peel may represent the epidermis, the white portion below may be similar to the subcutaneous cellular tissue and the fruit pulp can be compared to muscles.

Recently, a combination of self-directed training with feedback was described as the most effective method to teach basic technical skills, distributed intermittently over a pre-determined period (weeks)11. In training, feedback can be immediate (during training) and/or later (after training) and it is associated with better and faster learning, and also with a greater store up of knowledge over time9. In order to obtain an even longer store up and a larger transfer of competences, it is preferable the interspersed practice with periods of rest, in contrast to the single exposure to the method23.

Some limitations to this form of teaching (several days or weeks) would be: the higher financial costs, the shortage of faculty experts8 and the available time of faculty experts11,24. One way to reduce costs would be the adoption of bench models such as the organic model proposed here. This model can be reused if stored in proper cooling conditions.

The practice outside the classroom, at home, can reduce the length of supervised training, while the feedback from the instructor would be just on the procedures already performed (e.g., sutures and incisions), reducing the time of supervision; for this, it is necessary that students have learned, initially under the direct supervision of the instructor. The comments generated by computers could also be an option; however, the retention of skills over time is significantly larger when learned through direct feedback from an instructor8. The incorporation of trained students25,26 and of trained nonsurgeon skills coaches14 could also reduce the time spent by faculty instructors in the teaching of basic surgical skills. So, faculty surgeon would focus on teaching complex tasks and cognitive aspects of clinical training (decision making), that are not duties of the nonphysician skills coach14 neither to trained students27.

In the teaching of surgical skills, the objective assessment is an important component, it is essential for evaluating the performance and evolution of the acquired skills and to provide feedback on training12,28; and it helps to identify whether the proposed fundamentals have been learned by the student7. The student can attend the next stage of training since the predefined evaluation criteria are met12. If it does not happen, another step in the teaching-learning should be held and a new evaluation should be carried out7.

Currently, the Objective Structured Assessment of Technical Skills6 is the gold standard for this evaluation28,and it consists of a Global Rating Scale and a Task-Specific Checklist6. The Global Rating Scale adopted as an evaluation tool in this study is used to assess the generic aspects of technical performance and it has wide applicability without the need to develop specific lists for each procedure7.

The present proposal is structured only in the development of some skills and surgical tasks, it does not meet all the needs of students in training and it should include the acquisition of other skills (dissections, ligating structures, anastomosis and other)11 that can also be trained in simulation environments24.



The bench model made with fruits and/or vegetables, being simple, versatile, portable, reproducible, affordable, easy to purchase, and of low cost, is an option for supplementing the existing simulators for teaching and learning; it is aimed at preparing medical students before they can apply the surgical techniques in daily professional practice.



The authors thank to Dr. Cassio Eduardo Adami Raposo do Amaral for his comments and editorial suggestions concerning this manuscript.



1. Collins AM, Ridgway PF, Hassan MS, Chou CW, Hill AD, Kneafsey B. Surgical instruction for general practitioners: how, who and how often? J Plast Reconstr Aesthet Surg. 2010;63(7):1156-62.         [ Links ]

2. Gmajnić R, Pribić S, Lukić A, Ebling B, Cupić N, Marković I. Effect of surgical training course on performance of minor surgical procedures in family medicine physicians' offices: an observational study. Croat Med J. 2008;49(3):358-63.         [ Links ]

3. Hamadani F, Moroz PJ, Fairfull-Smith R. Proposal to improve the surgical skills of Canadian medical school graduates: the experiences of a medical student and staff surgeon with the Essential Surgical Skills Course in Kilimanjaro, Tanzania. Can J Surg. 2010;53(1):E5-6.         [ Links ]

4. Hammoud MM, Nuthalapaty FS, Goepfert AR, Casey PM, Emmons S, Espey EL, Kaczmarczyk JM, Katz NT, Neutens JJ, Peskin EG; Association of Professors of Gynecology and Obstetrics Undergraduate Medical Education Committee. To the point: medical education review of the role of simulators in surgical training. Am J Obstet Gynecol. 2008;199(4):338-43.         [ Links ]

5. Dubrowski A, MacRae H. Randomised, controlled study investigating the optimal instructor: student ratios for teaching suturing skills. Med Educ. 2006;40(1):59-63.         [ Links ]

6. Faulkner H, Regehr G, Martin J, Reznick R. Validation of an objective structured assessment of technical skill for surgical residents. Acad Med. 1996;71(12):1363-5.         [ Links ]

7. Khan MS, Bann SD, Darzi AW, Butler PE. Assessing surgical skill using bench station models. Plast Reconstr Surg. 2007;120(3):793-800.         [ Links ]

8. Porte MC, Xeroulis G, Reznick RK, Dubrowski A. Verbal feedback from an expert is more effective than self-accessed feedback about motion efficiency in learning new surgical skills. Am J Surg. 2007;193(1):105-10.         [ Links ]

9. Cannon-Bowers JA, Bowers C, Procci K. Optimizing learning in surgical simulations: guidelines from the science of learning and human performance. Surg Clin North Am. 2010;90(3):583-603.         [ Links ]

10. Grierson L, Melnyk M, Jowlett N, Backstein D, Dubrowski A. Bench model surgical skill training improves novice ability to multitask: a randomized controlled study. Stud Health Technol Inform. 2011;163:192-8.         [ Links ]

11. Jensen AR, Wright AS, Levy AE, McIntyre LK, Foy HM, Pellegrini CA, Horvath KD, Anastakis DJ. Acquiring basic surgical skills: is a faculty mentor really needed? Am J Surg. 2009;197(1):82-8.         [ Links ]

12. Sanfey H, Dunnington G. Verification of proficiency: a prerequisite for clinical experience. Surg Clin North Am. 2010;90(3):559-67.         [ Links ]

13. Rogers DA, Regehr G, MacDonald J. A role for error training in surgical technical skill instruction and evaluation. Am J Surg. 2002;183(3):242-5.         [ Links ]

14. Kim MJ, Boehler ML, Ketchum JK, Bueno R Jr, Williams RG, Dunnington GL. Skills coaches as part of the educational team: a randomized controlled trial of teaching of a basic surgical skill in the laboratory setting. Am J Surg. 2010;199(1):94-8.         [ Links ]

15. Grober ED, Hamstra SJ, Wanzel KR, Reznick RK, Matsumoto ED, Sidhu RS, Jarvi KA. The educational impact of bench model fidelity on the acquisition of technical skill: the use of clinically relevant outcome measures. Ann Surg. 2004;240(2):374-81.         [ Links ]

16. Köse AA, Karabağli Y, Arici M, Cetin C. Various materials may aid in teaching surgical procedures. Plast Reconstr Surg. 2004;114(2):611.         [ Links ]

17. Chen TM, Mellette JR. Surgical pearl: Tomato-an alternative model for shave biopsy training. J Am Acad Dermatol. 2006;54(3):517-8.         [ Links ]

18. Whallett EJ, McGregor JC. An alternative model for teaching basic principles and surgical skills in plastic surgery. J Plast Reconstr Aesthet Surg. 2011;64(2):272-4.         [ Links ]

19. Wanitphakdeedecha R, Nguyen TH, Chen TM. The banana: a surgery training model to refine blade control for Mohs layer removal and skin incisions. Dermatol Surg. 2008;34(8):1088-90.         [ Links ]

20. Empkie TM. Another exciting use for the cantaloupe. Fam Med. 1987;19(6):430.         [ Links ]

21. Bjellerup M. Novel method for training skin flap surgery: polyurethane foam dressing used as a skin equivalent. Dermatol Surg. 2005;31(9 Pt 1):1107-11.         [ Links ]

22. Boriani F, Degano K, Bruschi S. Basic surgical practice on discarded adipocutaneous flaps in massive weight loss surgery. J Plast Reconstr Aesthet Surg. 2010;63(2):e186.         [ Links ]

23. Moulton CA, Dubrowski A, Macrae H, Graham B, Grober E, Reznick R. Teaching surgical skills: what kind of practice makes perfect?: a randomized, controlled trial. Ann Surg. 2006;244(3):400-9.         [ Links ]

24. Klingensmith ME, Brunt LM. Focused surgical skills training for senior medical students and interns. Surg Clin North Am. 2010;90(3):505-18.         [ Links ]

25. Tolsgaard MG, Gustafsson A, Rasmussen MB, Høiby P, Müller CG, Ringsted C. Student teachers can be as good as associate professors in teaching clinical skills. Med Teach. 2007;29(6):553-7.         [ Links ]

26. Weyrich P, Celebi N, Schrauth M, Möltner A, Lammerding-Köppel M, Nikendei C. Peer-assisted versus faculty staff-led skills laboratory training: a randomised controlled trial. Med Educ. 2009;43(2):113-20.         [ Links ]

27. Robinson Z, Hazelgrove-Planel E, Edwards Z, Siassakos D. Peer-assisted learning: a planning and implementation framework. Guide supplement 30.7-practical application. Med Teach. 2010;32(9):e366-8.         [ Links ]

28. van Hove PD, Tuijthof GJ, Verdaasdonk EG, Stassen LP, Dankelman J. Objective assessment of technical surgical skills. Br J Surg. 2010;97(7):972-87.         [ Links ]



Rafael Denadai
Faculdade de Ciências Médicas
Universidade de Marília
Rua Paula Fabiana Tudela, 161
17516-707 Marília – SP Brasil
Tel./Fax: (55 14)3453-5456

Received: August 11, 2011
Review: October 16, 2011
Accepted: November 16, 2011
Conflict of interest: none
Financial source: none



1 Research performed at Division of Plastic Surgery, Department of Surgery, School of Medical Sciences, Marilia University (UNIMAR), Sao Paulo, Brazil.

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons