Haemodynamic study examining the response of venous blood flow to electrical stimulation

Objectives. The aim of this study was to explore the option of stimulating calf muscle contraction through externally applied neuromuscular electrical stimulation (NMES) and to measure venous blood flow response to this stimulation. Methods. Ten patients with class 6 chronic venous disease (CEAP clinical classification) were recruited. Measurements of peak venous velocities in the popliteal vein were recorded by Duplex scanning in response to six test conditions; 1. Standing, 2. Voluntary calf muscle contraction, 3. Standing with NMES applied, 4. Standing with compression bandaging applied to the leg, 5. Voluntary calf muscle contraction with compression bandaging applied to the leg, 6. Stationary with compression bandaging applied to the leg and NMES applied. Comfort assessment was completed using visual analogue scales at each test stage and on study completion each patient completed a short structured interview to determine comfort and acceptability of NMES. Statistical analyses were carried out using SPSS, Version 9. Non-parametric testing was used in all analyses using the Wilcoxon Signed Ranks Test for paired samples. Results. There was a significant increase in venous velocities on voluntary contraction of the calf muscle (median resting vel 7.3 cm/s; voluntary contraction median 70 cm/s) and with the introduction of NMES, both with compression (median velocity 15 cm/s, pZ0.005 Wilcoxon) and without compression (median velocity 13 cm/s, pZ0.005 Wilcoxon). The greatest increase with NMES was when combined with compression bandaging. All patients reported the stimulus as an acceptable treatment option with 90% reporting NMES as comfortable. Conclusions. Healing rates in venous ulceration with the application of compression bandaging remain between 50 and 70%. This study shows a positive haemodynamic response to NMES. Further research is needed to quantitatively measure the effect of NMES on ulcer healing.