The modified placenta model for microsurgery training: Recommended methods for comprehensive microsurgery experience.

Purpose: Currently, rats are the most preferred models for microsurgery training. However, living rats come with several limitations. The use of the placenta in this field is still restricted. Our aim was to increase the realism of the placenta model by introducing several improvements such as pulsation and thrombus models. Additionally, it was also aimed to provide a specific time schedule for the reliable use of the placenta.

Methods: The study included 30 placentas and 10 participants. Placentas were divided into three groups; Group A (ten placentas) were allocated for training. At the end of each training day, trainees were asked to complete a questionnaire. To obtain samples for histopathological evaluation another group (Group B) was formed. The placentas of both of the groups (A and B) were used as fresh at the first day and then stored in the refrigerator (under 4 ​°C) for the following 3 days. The remaining ten placentas (Group C) were kept at room temperature. This group was also subjected to histopathological analysis. Histopathological evaluation was performed to determine the necrosis ratio within the layers of Endothelium and Media (E/M). Vessels were divided into 6 levels and microscopically analysis was performed to determine the diameters of these vessels.

Results: The average questionnaire scores throughout the first three days were high enough to indicate a better/significantly better microsurgery experience compared to that on rats. Subsequent necrosis ratios (E/M) were relatively low during the first three days which confirms the results of the questionnaire. This is mainly attributed to the cold ischemia precautions taken during the study. The vessel diameters (A/V) of the placenta from level 1 to level 6 were as follows; 2.95/6.64, 3.56/3.84, 2.65/2.97, 1.63/1.82, 1.19/1.48 and 0.56/0.49 ​mm respectively.

Conclusion: The inclusion of pulsation and thrombus models in the modified placenta model enhances the realism of the microsurgery training experience. According to trainee feedback, the modified placenta model offered a superior training experience compared to living rats during the first three days. We recommend integrating this model with a living rat in a hybrid approach to obtain a comprehensive microsurgery training program.