Microsurgery Training Model Simulating Respiratory Motion

Microsurgery is an essential technique used in a wide range of reconstructive procedures, including free flap transfer and vascular reconstruction. However, microvascular anastomoses performed in the abdominal or thoracic regions are susceptible to respiratory motion. In particular, hepatic artery reconstruction is technically demanding because the anastomosis lies deep and is influenced by such motion. Consequently, temporary cessation of ventilation is sometimes required to secure a stable operative field (Katayama et al. 2025). Although a deep operative field can be simulated by adjusting the height of the working platform, reproducing a microsurgical environment influenced by respiratory motion has not yet been reported. Therefore, we developed a novel, simple, and low-cost training model that enables the simulation of a microsurgical environment affected by respiratory motion. This model was constructed using readily available materials, including components from plastic model kits manufactured by Tamiya Inc. (Shizuoka, Japan) and a commonly available low-speed motor. Tamiya kits, which include modifiable rails and casters, can each be purchased for only a few dollars, and the 10-rpm motor closely replicates the human respiration rate. The motor's rotational motion was converted into vertical displacement via a compact crank–slider mechanism that moved a small platform on which the artificial vessels were placed. The amplitude of this movement could be adjusted by changing the length of the attached linear rail; in our setup, the platform moved approximately 2 cm. Height-adjusting side blocks were placed on both sides to align the platform with the working height under the microscope. Although a 10-rpm motor was used to mimic normal respiration, the rate could be altered by replacing the motor unit. The device is entirely handmade and can be assembled in under an hour once the parts are prepared. It is not commercially available; however, all components are inexpensive and readily obtainable. By converting the rotational motion of the motor into a vertical movement, we created a platform that moves up and down at a constant rhythm, simulating the respiratory motion encountered during microsurgical anastomosis during hepatic artery reconstruction (Figure 1). Although numerous microsurgical training models have been reported, most have focused on the materials used for anastomosis (Javid et al. 2019). Our model is unique because it reproduces the intraoperative environment at a minimal cost. By replacing the motor with a higher-speed unit, this model can also simulate the motion encountered in cardiac surgery, such as coronary artery bypass grafting, indicating its broad applicability. Performing microvascular anastomosis using this model was substantially more challenging, time-consuming, and stressful compared to procedures conducted under static conditions (Video S1). However, it effectively reproduces the demanding surgical environment encountered in hepatic artery reconstruction and breast reconstruction involving anastomoses to the internal mammary vessels. It is also expected to serve as a useful tool for training under conditions of stress and periodic motion. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. The data that supports the findings of this study are available in the Supporting Information material of this article. Video S1: Demonstration of the training model in operation, showing microsurgical anastomosis of artificial training vessels performed with and without respiratory motion. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.