ACUTE EFFECTS OF INTERMITTENT SEQUENTIAL COMPRESSION IN VENOUS HYPERTENSION

Chronic venous hypertension produces microangiopathy which often progr esses to ulceration. It has been recently observed that intermittent s equential compression (ISC) increases the rate of healing of venous ul cers. The aim of this study was to investigate the effect of this form of therapy on the microcirculation in limbs with venous hypertension. Skin blood flow at rest (RF) was measured by laser Doppler flowmetry at the perimalleolar region at rest (horizontal position) and on stand ing in 34 limbs with chronic venous hypertension (17 with ulcerations) and 20 limbs of healthy volunteers. The venoarteriolar response (VAR = the vasoconstrictory response on standing) was also measured. Also 8 limbs with venous hypertension not treated with ISC were studied to e valuate the effects of supine resting alone on the microcirculation. T wo treatment protocols were used. In Study I intermittent sequential c ompression was applied for 30 minutes. Laser-Doppler measurements were performed at time 0 (before intermittent sequential compression) and after 50, 60 and 30 minutes. In Study 2 intermittent sequential compre ssion was applied for 60 minutes and measurements were performed at ti me 0 and after 60 and 120 and 180 minutes. In patients of Study I RF w as 1.45 +/- 0.8, significantly higher than in normals (p<0.05) and the venoarteriolar response only 7%, significantly lower than in normals. At the end of the compression period there was a marked change toward s normality as RF decreased (1.1 +/- 0.2) while the change in venoarte riolar response was not significant. At 60 and 30 minutes the changes in RF were still significant (p<0.05) and the VAR was significantly in creased (p<0.05). In Study 2 RF was 1.59 +/- 0.4, higher than in norma ls (p<0.05) and the venoarteriolar response 3%, significantly lower th an in normals. At the end of the compression period there was a marked change towards normality as RF decreased (0.73 +/- 0.2) and the venoa rteriolar response was significantly higher (p<0.05). At 120 and 180 m inutes the decrease in RF and increase in venoarteriolar response were Still significant (p<0.05). No significant changes were observed in n ormals and in control patients in both studies. Conclusions: The findi ngs offer an explanation on the remarkable effect of sequential compre ssion on the healing of leg ulcers. The improvement in RF and in venoa rteriolar response towards normality appears to be dose-related to the period of intermittent sequential compression used and it persists we ll after the end of the intermittent sequential compression session.