Skin perfusion pressure in leg ulcers assessed by photoplethysmography

The aetiology of lower limb ulcers is often the result of intricate vascular pathology and the quality of the peri-ulcer microcirculation is a major factor in the prognosis of the disease. We measured the skin perfusion pressure (S.P.P.) using an infra-red photoplethysmograph of the PPG type (ESM, Mauguio, France). The study included 30 healthy subjects, 25 patients with leg ulcers of varied etiology (venous: 14, arterial: 11), and 15 patients with uncomplicated varicose veins. Measurements were undertaken in dorsal decubitus position after a 15 minute rest. The S.P.P. was expressed as the percentage of humeral blood pressure. The results showed an important decrease of S.P.P. in patients with arterial ulcers when compared to patients with healthy legs (39.9 +/- 16.4% and 82.8 +/- 10.0% respectively). The S.P.P. values were intermediate (54.4 +/- 19.3%) in patients with venous ulcers while they were normal in the patients with uncomplicated varicose veins (87.3 +/- 12.3%). Among this population, 18 patients (11 with uncomplicated varicose veins and 7 with venous ulcers) were investigated before and after a one month treatment with a flavonoid (Daflon 500 mg, 2 tablets per day). An increase of S.P.P. to normal values after treatment was found in patients with venous ulcers though not in patients with varicose veins. This non invasive procedure appreciating the microcirculation status in peri-ulcerous skin could be of predictive value for the healing potential. It could be a good method to assess the efficacy of vasculotropic agents.