New silicone model for training surgical skills
Researchers at Karl Landsteiner University developed a new, cost-effective training model for suturing gastric perforations. By bundling various competencies from the organisational units "Division of Biomechanics", “Division of Surgery” at the Tulln site, “Division of Radiotherapy” at the Krems site and the study programme “Human Medicine”, it was possible to design a cost-effective, reproducible, and reusable silicone model meant for the training of medical students. The model was compared and evaluated with real pig stomachs regarding their haptic and mechanical properties as well as their behaviour during suturing.
Gastric perforation can be life-threatening
Gastric perforation can occur due to various causes and can even be fatal. Rapid therapy is necessary. The various surgical techniques used to treat gastric perforation must be well-practised and the gastric mucosa has to stay intact during surgery. Neither training on humans nor on animal tissues is always possible to a sufficient extent, which is why there is a great need for suitable artificial models. The researchers at Karl Landsteiner University set themselves the goal of producing a silicone model that is as similar as possible to the stomach wall and can thus be ideally used for suture training of gastric perforations. Three different models were produced with the help of a 3D printer. These consisted of two or three different silicone layers. To obtain realistic suturing behaviour, one of the layers of each of the three models was enriched with PU foam.
How realistic are the resulting silicone models?
To test how realistically the silicone models behave, their properties were compared with the stomach wall of pigs. Porcine stomachs are similar in structure to the human stomach wall and were obtained from a butcher and stored and prepared in compliance with the appropriate hygiene and freshness regulations. The subjectively perceived haptic properties between the silicone models and the porcine stomach wall were evaluated by selected surgeons and technicians using a four-part scale on six different properties (overall structure, stiffness in the transverse and longitudinal directions, force required for cutting and piercing, resistance to tearing out the thread). During a mechanical penetration test, a needle pierces the silicone or porcine stomach wall sample with the same force and speed. Therefore, the test sample was clamped in a specially-made holder. It turns out that none of the silicone models can completely replicate porcine stomach tissue, but two models come very close to the natural tissue. In the haptic evaluation, the 3-layer model performs best.
Relevance of the development
The evaluation of the silicone training model was not carried out in comparison with human tissue but with very similar animal tissue. Even though not all properties can be reproduced 100%, the model allows a very good approximation of the properties of porcine stomachs, and it can be assumed that training on the silicone model will bring advantages for the training of surgeons and their suturing techniques. The study authors have ensured that the training silicone model can be easily and inexpensively replicated. The complementary skills of translational research and clinical need in the work have resulted in an easy-to-implement extension in the field of medical education. The results were published freely available in the journal BMC Medical Education.