Related Experiment Video
Updated: Aug 8, 2026
Non-invasive Assessment of Microvascular and Endothelial Function
Published on: January 29, 2013
Critical leg ischaemia: an appraisal of clinical definitions. Joint Vascular Research Group
1St Mary's Hospital Regional Vascular Unit, London, UK.
Insights
Predicting critical limb ischemia (CLI) is challenging. Current definitions poorly predict amputation risk, especially in diabetics, and graft occlusion, highlighting the need for improved diagnostic tools.
Area of Science:
- Vascular Surgery
- Clinical Medicine
- Medical Diagnostics
Background:
- Predicting critical limb ischemia (CLI) and subsequent amputation is a significant clinical challenge.
- Existing definitions of CLI from the International Vascular Symposium and European working parties lack prospective validation.
- Diabetic patients face a higher risk of amputation compared to non-diabetics, irrespective of initial ankle artery pressures.
Purpose of the Study:
- To prospectively evaluate the reliability of existing and modified definitions of critical limb ischemia in predicting amputation.
- To assess the ability of these definitions to predict graft occlusion and associated mortality.
- To investigate the specific challenges in predicting outcomes for diabetic patients with CLI.
Main Methods:
- Prospective data collection over 3 years for 213 patients with critical limb ischemia.
- Evaluation of two established definitions of critical limb ischemia and one simplified modification.
- Analysis of amputation rates, graft occlusion, and mortality in relation to the applied definitions, with subgroup analysis for diabetic patients.
Main Results:
- All evaluated definitions demonstrated poor sensitivity, specificity, and positive predictive values for identifying patients requiring amputation without successful arterial reconstruction.
- No definition could reliably predict amputation risk in diabetic patients, who had higher amputation rates than non-diabetics.
- Graft occlusion was not reliably predicted by any definition, and associated with a 3-year mortality rate of approximately 35%.
Conclusions:
- Current definitions of critical limb ischemia are inadequate for reliably predicting amputation risk, particularly in diabetic patients.
- Arterial reconstruction significantly reduces mortality and amputation rates in patients with critical limb ischemia.
- The study did not support the hypothesis that critical limb ischemia is associated with a higher graft occlusion rate than less severe ischemia.
Abstract:
The reliable prediction of imminent limb death remains a clinical problem. The International Vascular Symposium and European working parties each produced similar definitions of 'critical ischaemia', but this is the first attempt to address the issue with prospectively collected data. Complete 3-year follow-up data were available for 213 patients. In addition to the above two definitions, a simplified modification has been evaluated, after review of the data 1 year into this study. All three definitions were able to identify patients likely to require amputation in the absence of successful reconstruction. The sensitivity, specificity and positive predictive values with which they were able to do so was, however, poor. None of the definitions was able to predict which diabetic patients would require amputation. Diabetics were more likely to undergo amputation than non-diabetics. There was, however, no significant difference in the initial ankle artery pressures between the diabetic and non-diabetic patient subgroups. None of the definitions reliably predicted which grafts would occlude, in which event the 3-year mortality rate was approximately 35 per cent. Critical ischaemia by any of these definitions is associated with a high mortality rate. Arterial reconstruction is associated with a reduction in both mortality and amputation rates These data do not support the hypothesis that critical ischaemia is associated with a greater graft occlusion rate than lesser degrees of severe ischaemia.
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