[Epidemiology from the Trans Atlantic Inter-Society Consensus Group Guidelines II].

Although there is little direct information or prospective cohort study on the incidence and prevalence of critical limb ischemia (CLI), it can be calculated that the incidence of CLI is approximately 500 to 1,000 per million per year in Western countries and 100 to 200 in Japan. The most important risk factor for the development of CLI is diabetes as well as age, cigarette smoking, lipid abnormalities, and low ankle brachial pressure index. Without pharmacotherapy or interventions, approximately 40% of CLI patients will lose their leg within 6 months, whereas up to 20% will die. As most generally have widespread atherothrombosis in various organs such as ischemic heart disease, cerebrovascular disease, and renal dysfunction, patients with CLI have 20% mortality in the first year. The early hospital mortality rate after amputation is high and the long-term survival rate of amputees is low. An attempt to perform optimal revascularization to keep the level of amputation below the knee is mandatory to prevent above-knee amputation resulting in poor life expectancy and loss of full mobility.