In vivo Microscopic Study of Microcirculatory Perfusion of the Skin of the Foot in Peripheral Vascular Disease

Abstract

Objectives: the aim of this study was to determine the proportion of perfused capillaries in the skin of the foot in patients with peripheral vascular disease, and compare it with that in normal subjects. Design: experimental study comparing capillary perfusion in nine patients with severe peripheral vascular disease (group 2) with seven age- and sex-matched control subjects (group 1). Materials and methods: using in vivo video microscopy, a method was developed to measure the ratio of perfused to total capillaries, by comparing the numbers of corresponding capillaries before and after intravenous injection of sodium fluorescein. Results: the mean percentage ratio of perfused to total capillaries was 54.7% (range 41–87%, standard deviation 16.5) in group 1, and 86.0% (range 62–100%, standard deviation 13.2) in group 2 (p<0.001, t-test). Conclusion: a significantly higher proportion of capillaries is perfused in the skin of the foot of patients with severe peripheral vascular disease than in that of normal subjects. This is of important pathophysiological significance and may have clinical implications with regard to the role of pharmacological intervention in severe limb ischaemia.