Meta-analysis of the prevalence, incidence and natural history of critical limb ischemia.

Critical limb ischemia (CLI) is a significant morbid condition among the elderly. The epidemiology and natural history of this condition are poorly defined.Systematic review and meta-analysis of studies evaluating the prevalence, incidence and natural history of CLI were performed.Six studies reported on the prevalence of severe lower limb ischemia (ABI <0.60, ankle pressure <70 mmHg or Fontaine III-IV) in 82,923 subjects and its pooled prevalence was 800/100,000 population (95%CI 300-1400). The Oxford Vascular Study assessed the incidence of vascular events in the general population and estimated an incidence of CLI of 22/100,000 population per year (95%CI 17-28). Two studies reported an incidence of CLI in subjects >65 years old of 113 and 200/100,000 population per year, respectively. Nine studies reported on the treatment strategy in 2144 legs with CLI: the pooled rate of any revascularization procedure was 70.4%, of primary amputation 8.4%, and of conservative treatment 20.3%. After conservative treatment for CLI, one-year pooled leg salvage rate was 57.4% (95%CI 45.1-69.7%, ten studies reporting on 734 legs included), survival 75.4% (95%CI 59.2-91.6%, four studies included) and amputation-free survival 51.4% (95%CI 32.7-71.2%, five studies included).The incidence of CLI in the elderly is rather high. Series reporting on treatment strategies in these patients showed that a revascularization is attempted in 70% of cases. Conservative treatment in patients with unreconstructable CLI, high operative risk and/or refusing any revascularization procedure is associated with acceptable one year leg salvage.