Low-cost, synthetic model for training and simulation of open and semi-open rhinoplasty
Modelo sintético e de baixo custo para o treinamento e simulação de rinoplastia aberta e semiaberta

INTRODUCTION

Rhinoplasty is the surgery indicated for performing aesthetic repairs in the nose, being functional when it aims to improve respiratory function. Its first report was described in India, around 500 BC, by Sushruta, considered the father of plastic surgery, who used various reconstructive techniques on individuals who had their nose cut off. From this report, the techniques were improving more and more, and publications about this procedure became common. In the late 1500s, Professor Gaspare Tagliacozzi showed the possibility of nasal reconstruction using an arm flap; in the mid-1800s, Johann Friedrich Dieffenbach’s textbook entitled “Operative surgery” described techniques for reducing the size of the nose. Since then, rhinoplasty has become increasingly refined based on theoretical and practical training provided by trained professionals¹.

Today, rhinoplasty is a widespread procedure. The evaluation of its results is based on improving the quality of life and patient satisfaction, which also depends on factors such as preoperative appearance, expectations and the doctor-patient relationship, and adequate training². According to Oni et al. (2011)³, more than half of the residency program directors evaluated did not feel confident in the residents’ ability to perform rhinoplasty. Much of this is due to the absence of early exposure and little training time⁴. Despite this, several techniques were introduced, such as educational videos, simulations, studies on cadavers and clinical skills laboratories, but the training base remains the master-apprentice relationship in surgical procedures, which limits the resident’s development⁵. It is essential to emphasize that many alternative educational tools involve high financial costs and training in patients may face restrictions due to the lack of hospital structure and resources for the procedure.

Rhinoplasty is considered the most difficult of all cosmetic surgeries, as the nasal anatomy is highly variable, the procedure must correct form and function, and the result must meet the expectations of patients⁶. Therefore, it is necessary to reinforce surgical learners’ anatomical knowledge and technical skills, using strategies to increase training time and tools that, preferably, are low-cost and easily accessible.

OBJECTIVE

This article aims to present a synthetic, novel and practical model for training in rhinoplasty techniques, developed to be easy to perform and low cost.

METHODS

The study was carried out at the University of Fortaleza (UNIFOR), in Fortaleza/CE, from September 2020 to December 2020. All ethical aspects of the research were followed and respected.

Figure 1 - Materials needed for making the model.

Figure 1 - Materials needed for making the model.

To assemble the proposed model, the following materials were used: hot glue, basin, water, detergent, epoxy putty, spatulas for crafts, nose mold (Carnival mask), suture threads and white acetic silicone (Figure 1). To color the parts of skin and cartilage, it is necessary to use dye and a disposable cup and spoon.

Cartilages

Cartilage construction was made from acetic silicone and an epoxy mass mold (Figure 3). This mold was handcrafted, simulating the shape of the upper and lower lateral cartilages (Figure 4).

The epoxy putty was prepared and allowed to rest for 10 minutes to gain sufficient consistency to be carved with the craft spatulas. After the mass had dried, the silicone was poured into the mold and kept until it hardened. Then, it was removed from the mold and placed in a ventilated place for complete drying and reduction of the intense odor (Figure 5).

Figure 2 - Bone part made with hot glue.

Figure 2 - Bone part made with hot glue.

Figure 3 - Silicone cartilages and the material for their manufacture.

Figure 3 - Silicone cartilages and the material for their manufacture.

Figure 4 - Cartilage molds made of epoxy putty using a craft spatula.

Figure 4 - Cartilage molds made of epoxy putty using a craft spatula.

Figure 5 - Inferior lateral cartilages ready.

Figure 5 - Inferior lateral cartilages ready.

Skin

For confection, the dye was added to white acetic silicone in a disposable container. Then, the mixture was placed in a basin with water and neutral detergent, being kneaded and rolled by hand until, after a few minutes, a slight hardening of the mass was observed (Figure 6).

Figure 6 - Ready-made leather and the materials needed for its construction.

Figure 6 - Ready-made leather and the materials needed for its construction.

The most consistent silicone was placed in a plastic mold similar to a nose greased with oil and left to dry. Silicone has a powerful smell and, in contact with the skin, can cause dry hands. So, protection with gloves and a mask is essential.

With the cartilages adequately dried, they were fixed to the bone structure with suture threads (Figure 7). After that, the skin was used to cover the structure and fixed with a suture to remain immobile (Figure 8).

The skin was made to provide a better visual appearance to the model, as its construction will not significantly influence the training period.

Figure 7 - Cartilages attached to the bone structure.

Figure 7 - Cartilages attached to the bone structure.

Figure 8 - Fixed skin covering the structure.

Figure 8 - Fixed skin covering the structure.

Figure 9 - Cartilage exposure using open and semi-open techniques.

Figure 9 - Cartilage exposure using open and semi-open techniques.

Figure 10 - Completion of the simulation using open and semi-open techniques.

Figure 10 - Completion of the simulation using open and semi-open techniques.

RESULTS

A format similar to the real one was obtained regarding the bone and cartilaginous structure, as shown in the following images. In addition, color differentiation between cartilages and nasal bones helps identify each structure (Figure 9).

The complete structure allows for a very real rhinoplasty simulation, making it possible to perform a columellar incision for open access and perform maneuvers on the nasal tip and the back, such as the execution of sutures and the eventual placement of grafts (Figure 10).

DISCUSSION

Surgical training involves complex practical and theoretical concepts, mainly related to the surgical technique and its fundamental bases, among which the development of skills is considered essential. In general, psychomotor skills are acquired through the observational model, known as “see, do and repeat”⁷.

In order to expand skills training beyond operating rooms, it is essential to develop viable options with as much similarity as possible to the patient’s tissue. An obvious option would be to study fresh cadavers, but due to legal obstacles that make it challenging to obtain this material in Brazil, it is still scarcely available⁸.

Some experimental models for training surgical skills related to rhinoplasty have already been published, such as the animal model proposed by Dini et al. (2012)⁸, which revealed great applicability. However, the use of a non-human material also presents several ethical and bureaucratic complications and does not show complete similarity. Furthermore, there is a conflict with modern concepts of animal welfare. Students’ misinformation about ethics and the use of animals, associated with the obligation to participate in educational activities that use this teaching method, without the legal right to conscientious objection or the option of alternatives, have been related as a cause of desensitization professionals⁹.

Therefore, the current diversity and complexity of medical-surgical knowledge require a new direction in teaching through innovative strategies. Several alternative precepts, also called “substitutives,” have been exercised to ensure the acquisition of skills, seeking to fulfill the educational/scientific function without harming the animals. The intention should be to disseminate, at the ideal time, the knowledge necessary for adequate professional training, enhancing learning and reducing or abolishing the use of animals⁷.

The new synthetic model developed allows for excellent identification of structures, adequate mobilization of nasal cartilages and easy handling of the overlying synthetic skin, with consistency, texture and resistance similar to the real thing. Allows good simulation of some steps of the open and semi-open techniques of rhinoplasty. The upper and lower lateral cartilages made with silicone, when sutured, provide a tactile sensation close to that of this surgical stage in patients. Synthetic skin has a certain elasticity, like what is observed when performing an open rhinoplasty. It should be noted that this model has already been used in a hands-on course, at the XV North-Northeast Congress of Otorhinolaryngology, in August 2019, when several surgeons were able to learn about the model and realize its similarity to the real one.

In addition to all these technical characteristics of the model, it should be noted that it does not raise ethical or legal questions that animal models or training in fresh human corpses inevitably impose due to its synthetic nature. In addition, another strong point is its low cost, which favors its replication in medical schools. In this way, it can provide more time and training options for apprentices in this refined surgery.

On the other hand, the main limitation of this model is that it requires relatively complex manual skills for its construction. In addition, some steps, for example, making the bone structure with hot glue, require some abstraction capacity for construction, as there is no sketch of the three-dimensional shapes of the face.

Finally, with the presentation of this model, the authors hope to make a relevant contribution to medical education and, at the same time, encourage the emergence of new models that improve it, based above all on the creative use of simple, easily accessible materials and low cost.

CONCLUSION

The exposed model has the potential to positively impact the rhinoplasty learning process, revealing itself as an accessible and helpful tool for training in the various stages of the technique of this complex surgery.