Patterns of skin flowmotion in the lower limbs of patients with chronic critical limb ischaemia (CLI) and oedema

Objective: to study flowmotion (FM) in lower limbs with critical limb ischa emia (CLI) and oedema and to elucidate FM patterns when skin viability is t hreatened. Material and methods: fourteen patients with unilateral CLI and oedema and two control groups were included - one consisting of 10 healthy participant s and the other nine patients with unilateral CLI without oedema. Laser Dop pler was used to evaluate the foot skirt microcirculation simultaneously at four different areas, with the limbs in supine and dependent position. FM was expressed using fast Fourier transformation (FFT) as low frequency (LF) and high frequency (HF) waves and their respective FFT-powers. Results: all patients with CLI, both with and without oedema, showed HF wav es in both diseased and contralateral limbs. These were absent in healthy c ontrols. There were no regional differences in frequency in the critically ischaemic feet (with and without oedema) and between ischaemic and their co ntralateral feet. Changing the position of ischaemic limbs from supine to d ependency had no significant effect on the frequency, while a significant i ncrease of the median FFT-powers of LF and HF waves at the pulp of the firs t toe was observed. This manoeuvre resulted in decrease of the medium FFT-p owwrs of LF in healthy controls. Conclusions: HF waves are associated with CLI. Ischemia also appears to inf luence the FFT-power of each frequency domain. Ischaemic oedema does not se em to affect the pattern of FM in the foot of patients with CLI.