Objective: Current treatment of venous leg ulcers (VLU) includes four-layer bandaging, appropriate superficial venous surgery and leg elevation. The aims of this study were to: investigate a device designed to measure leg elevation; assess how long patients elevate; and to assess the effect of elevation on ulcer healing, femoral vein velocity (FVV) and popliteal vein cross-sectional area (PVCSA), and venous pressure.
Patients and methods: A datalogger and accelerometer were manufactured to measure leg elevation. The device was validated in eight control subjects; elevation was measured in 24 patients with VLU. Ulcers were traced over six weeks in 29 patients and elevation measured to correlate healing with elevation. Ten patients and 10 controls underwent duplex measurement of FVV and PVCSA to measure flow in relation to posture; nine patients underwent measurement of venous pressure with postural changes. Non-parametric statistical analysis was used.
Results: The datalogger accurately recorded all episodes of elevation. Median (range) elevation time was 53 (0–350) mins/24 h; correlation between ulcer healing and elevation was poor at 0.103 ( P=0.616, Spearman); change in posture from sitting to supine produced a significant increase in median (range) FVV from 11 (7–24) to 34 (22–66) in VLU ( P=0.005) and 15 (12–34) to 38 (16–69) in controls ( P=0.005, Wilcoxon). Change in posture from supine to 25 degrees elevation produced no change in FVV in either group ( P=0.173 in VLU, P=0.327 in controls, Wilcoxon). In VLU, sitting PVCSA was 1.07 (0.51–1.45) cm ² . Supine position significantly reduced the area to 0.46 (0.27–1.01) cm ² ( P=0.005, Wilcoxon). On elevation to 25°, PVCSA was further reduced to 0.28 (0.07–0.63) cm ² ( P=0.058, Wilcoxon). In controls, sitting PVCSA was 0.79 (0.31–1.56) cm ² , supine was reduced to 0.46 (0.27–1.09) cm ² ( P=0.047, Wilcoxon) and on elevation was reduced to 0.23 (0.10–0.44) cm ² ( P=0.005, Wilcoxon). Venous pressure standing was 99 (73–116) mmHg, reduced to 76 (53–113) mmHg on sitting ( P=0.084), and further reduced to 23 (7–36) mmHg supine ( P=0.008, Wilcoxon).
Conclusions: Leg elevation in patients with VLU is poor but can be accurately measured. Elevation in the presence of compression may not improve ulcer healing. Postural changes of the leg can produce an increase in deep venous flow and a reduction in venous pressure.