Importance of cutaneous postural reflex vasoconstriction in patients with atherosclerotic occlusive disease of the lower extremities.

OBJECTIVE

The present study was designed to measure the cutaneous postural vasoconstrictive reflex (PVR) in normal controls and patients with atherosclerotic occlusive disease of the lower extremities, and to determine its diagnostic and prognostic relevance.

EXPERIMENTAL DESIGN

The postural vasoconstrictive reflex was recorded in 34 patients with atherosclerotic occlusive disease of the lower limbs and 27 normal controls, using laser-Doppler flowmetry. Patients also had ankle and toe pressure measurements and transcutaneous oximetry (TcPO2).

SETTING

University hospital.

RESULTS

The PVR on the pulp of the big toe was 20+/-7 arbitrary perfusion units in normal controls, 9.4+/-12 in patients with claudication, and -19 +/- 5 in patients with rest pain and/or gangrene, who differed from the claudicant and control groups (p=0.001 and 0.0001 respectively). The sensitivity of negative PVR in the big toe was 89% for the diagnosis of rest pain and/or gangrene, and its specificity, 83%. The severity of foot ischaemia and PVR values exhibited a significant inverse correlation (r=-0.56, p<0.0001). All patients with a poor outcome, ie. death and/or major amputation within 100 days of follow-up, had a negative PVR, and all patients with a positive PVR had a good 100-day prognosis without even a minor amputation.

CONCLUSIONS

Laser-Doppler provides useful additional information in the assessment of foot ischaemia severity by showing that postural vasoconstriction is impaired in patients with severe atherosclerotic occlusive disease of the lower limbs, resulting in increased skin microcirculatory flow during leg dependency.