Supermicrosurgical Anastomosis Training Using Chick Embryos within the Egg-in-Cube System.

Summary: Although supermicrosurgery techniques are essential skills for lymphatic surgery or perforator-flap surgery, an ideal training model is yet to be introduced. Living animal models, such as rodents, are considered to be ideal microsurgical training models. However, the use of living animal models is costly and involves bioethical considerations. Hence, the authors developed a novel, cost-effective, highly reproducible, and easy-to-handle supermicrosurgical anastomosis training system using the chicken embryo within the egg-in-cube system. Chick embryos were fertilized in the artificial cubic eggshell, which was fabricated by integrating a polycarbonate frame structure and five polydimethylsiloxane membranes. Seven days later, the trainees underwent supermicrosurgical training using the vitelline artery of the chick embryo. The trainees were able to perform supermicrosurgical training using all 11 surviving chicken embryos. The average diameter of the vitelline artery was 0.43 mm. Patency and pulsation were observed after the anastomosis in four of the 11 cases. The supermicrosurgical training system using the chicken embryo within the egg-in-cube system has several advantages. This system is ethically acceptable, less costly and easier to manage than other animal models, and suitable as a supermicrosurgical training model, such as for lymphovenular anastomosis, because the diameter of the vitelline artery was similar to that of the lymphatic vessels in patients with lymphedema. Moreover, the trainee can confirm patency and leakage after the anastomosis because this model has a circulation system. The trainee can practice the supermicrosurgical technique efficiently with simultaneous feedback on anastomosis results.

Clinical Relevance Statement: This study introduces a novel, cost-effective supermicrosurgical training system using chicken embryos within an egg-in-cube, offering a practical and ethical alternative. Its close simulation to human lymphatic vessels supports skill enhancement for practicing surgeons.