LASER-DOPPLER AND TRANSCUTANEOUS OXYMETRY - MODERN INVESTIGATIONS TO ASSESS DRUG EFFICACY IN CHRONIC VENOUS INSUFFICIENCY

During chronic venous insufficiency (CVI), microcirculatory changes, e .g. a decrease in transcutaneous oxygen pressure (tcpO(2)) and an incr ease in transcutaneous carbon dioxide pressure (tcpCO(2)), are implica ted in the pathophysiology of trophic disorders leading ultimately to venous ulcers. Daflon 500 mg(1), a micronized purified flavonoid fract ion, has been shown to improve venous tone, capillary permeability and resistance, and lymphagogue activity at a daily dose of 2 tablets. To assess the effects of Daflon 500 mg on microcirculatory parameters by means of laser Doppler fluxmetry and transcutaneous oxymetry, a 3-mon th, double-blind, randomized, parallel-group study was carried out in 104 patients divided into 3 groups according to the daily dose: 1 tabl et (group 1, n = 34), 2 tablets (group 2, n = 33), on 4 tablets (group 3, n = 37). All patients (mean age 43.7 +/- 13.1 years; 100 females, 4 males) included in the study were affected by mild CVI. They were fo llowed for 90 days with visits at 1 month (day 28) and 3 months (day 9 0). At inclusion, there were no significant differences between groups as regards biometric data, mean tcpO, (group 1, 62.7 +/- 4.5 mm Hg; g roup 2, 64.0 +/- 3.3 mm Hg; group 3, 64.1 +/- 3.5 mm Hg), mean tcpCO(2 ) (group 1, 40.7 +/- 2.5 mm Hg; group 2, 39.3 +/- 2.9 mm Hg; group 3, 40.0 +/- 2.5 mm Hg) and laser Doppler parameters. Fourteen patients wi thdrew from the study (group 1, n = 4; group 2, n = 3; group 3, n = 7) : 9 for reasons not related to treatment, 3 for adverse events, 2 beca use they were lost to follow-up. From day 0 to day 90, mean tcpO(2) si gnificantly increased (p < 0.001) in each group (group 1, 3.0 +/- 2.1 mm Hg; group 2, 2.9 +/- 2.1 mm Hg; group 3, 2.5 +/- 1.6 mm Hg), mean t cpCO(2) significantly decreased (p < 0.001) in each group (group 1, 2. 6 +/- 2.0 mm Hg; group 2, 1.7 +/- 1.9 mm Hg; group 3, 2.2 +/- 1.5 mm H g). No significant differences were observed between groups. Laser Dop pler parameters remained unchanged from day 0 to day 90 in the 3 group s. Symptoms (discomfort, pain, heaviness, burning sensation) and signs (oedema) of CVI as well as perimetric measurements of calf and supram alleolar area were significantly improved in the 3 groups. In conclusi on, during this 3-month study, Daflon 500 mg improved oxymetric measur ements and did not alter laser Doppler parameters. These data suggest that Daflon 500 mg, at the early stages of CVI, acts favourably on the microcirculatory disturbances also involved in the pathophysiology of more severe stages of CVI.