Experimental Models for LVA in Large Animals

Experimental models are crucial in surgical research and training, especially for complex procedures like lymphaticovenous anastomoses (LVA), which require supramicrosurgical techniques. Domestic pigs (Sus scrofa domesticus) are particularly useful in LVA training due to their similar vascular and lymphatic anatomy to humans, making them ideal for simulating human lymphatic microsurgery. Magnification, including an operating microscope and loupes, is critical during surgery due to the small size of the vessels involved. The surgical site is chosen based on the location of lymphatic channels and lymph nodes, and lymphatic vessels are visualized using indocyanine green mapping. In this chapter, the detailed step-by-step procedure of performing LVAs in pigs is described and illustrated, emphasizing the choice of suture material and instruments for different vessel sizes, providing recommendations for knotting techniques during the procedure, discussing the assessment of anastomosis patency, and highlighting the surgical site closure process. Results regarding the size of lymphatic vessels in pigs, the correlation between vessel size and patency rate, and objective methods for assessing flow rate and anastomosis patency are described, together with the advantages, disadvantages, limitations, and complications associated with using the pig model for LVA training and research. In conclusion, pigs are an excellent animal model for lymphedema training, given their large lymphatic vessels and ease of acquisition, with great potential for future investigations on lymphatic regeneration using this model.