Animal Models of Secondary Lymphedema: New Approaches in the Search for Therapeutic Options.

Secondary lymphedema is still a worldwide problem. Symptomatic approaches to lymphedema therapy have been mainly used, with complete decongestive therapy as the cornerstone. Due to a lack of regenerative therapy, researchers have established various animal models to obtain insights into pathomechanisms and to reveal the best therapeutic option. Since the first reproducible and reliable animal model of lymphedema was reported in dogs, the technique of circumferential excision of lymphatic tissue has been translated mainly to rodents to induce secondary lymphedema. In these models, various promising pharmacological and surgical approaches have been investigated to improve secondary lymphedema therapy. Imaging modalities are crucial to detect the extent of lymphatic dysfunction and decide the best therapy. The gold standard of lymphoscintigraphy is currently limited by poor spatial resolution and lack of quantification. Animal models could help to bridge a gap in improving morphological correlation and quantifying lymphatic functionality. This review summarizes the animal models used in lymphatic research and focuses on new therapeutic options and requirements for imaging modalities to visualize the lymphatic system.