Among all chronic ulcers of the lower extremities, the proportion of ulcers caused by venous diseases is more than 90%, and the remaining less than 10% are caused by arterial diseases, thrombo-occlusive vasculitis, lymphatic obstruction, as well as neurological diseases, metabolic disorders, hematological disorders and lipofuscinosis. It can be seen that chronic ulcers of the lower extremities are mainly caused by peripheral vascular diseases, which can be roughly divided into the following two categories: one is stasis ulcers, i.e. venous ulcers, mainly caused by stasis of blood in the veins of the lower extremities; one is ischemic ulcers, which can also be called arterial ulcers, mainly caused by insufficient blood supply to the arteries of the lower extremities, and ulcers caused by thrombo-occlusive vasculitis are also classified as such. The above two types of ulcers can also be intermingled and seen at the same time. Zhao Donghong, Department of Plastic and Reconstructive Surgery, General Hospital of Jinan Military Region