Measurement of blood flow in the deep veins of the lower limb using the geko™ neuromuscular electro-stimulation device.

BACKGROUND: A previous study using electrical stimulation of the common peroneal nerve (geko™) to activate the venous muscle pump measured blood flow in both the femoral and popliteal veins. Increased blood flow by as much as 60% was demonstrated in the femoral vein. Such an increase is assumed to be as a result of an increase in venous flow from the deep calf veins; however this has yet to be confirmed. The aim of this study was to conduct direct measurements in these deep calf veins to confirm this assumption in healthy individuals. METHODS: This was a single centre open-label intra-subject healthy volunteer comparison of blood flow in the peroneal, posterior tibial and gastrocnemial veins with and without the geko™ device. The device was applied to 18 volunteers. Peak venous velocity (PV) and ejected volume per individual stimulus (VS) and volume flow (VF) was determined using ultrasound. RESULTS: Peak velocity (PV) increased 216% in the peroneal vein, by 112% in the posterior tibial vein and by 137% in the gastrocnemial vein (P<0.001). Ejected volume per stimulus increased by 113% in the peroneal vein, by 38% in the posterior tibial vein and by 50% in the gastrocnemial vein (P<0.003). Associated volume flows during the muscle contraction were increased by 36%, 25% and 17%, respectively (P=0.05) CONCLUSIONS: This is the first time that neuromuscular electro-stimulation has been shown to be an effective method of increasing flow in the axial deep veins of the calf. Significant increases in velocity and volume flow in response to the electrical stimulus were seen in all three veins studied. Enhancements of both blood velocity and volume flow are key factors in the prevention of venous stasis and ultimately deep vein thrombosis (DVT). Further studies are justified to determine the efficacy of the device in the prevention of DVT.

The LONFLIT4-VENORUTON study: a randomized trial prophylaxis of flight-edema in normal subjects.

This study evaluated the protective effects of Venoruton on the development of flight edema in normal subjects travelling in economy in long-haul flights (8-9 hours). Edema is a relevant aspect of long-haul flights affecting both venous patients and normal subjects. Edema and flight microangiopathy were studied in a group of 164 subjects randomized (after informed consent) into two groups to evaluate prophylaxis in 8- to 9-hour flights. The treatment group received Venoruton (hydroxyethyl rutosides) 1 g twice daily for 3 days (2 days before the flight and the day of the flight). The control group received comparable placebo. Edema was evaluated with a composite edema score based on the edema tester, on the measurements of ankle circumference, volume measurements, subjective swelling, and on a discomfort score. Items 1, 4, and 5 are based on an analogue scale line (1 to 10) directly defined by the subjects before and after the flights. Of the included subjects, 151 completed the study. Dropouts were due to poor compliance, travelling, or connection problems. Age and gender distribution were comparable in the two groups as were risk factor distributions. The level of edema at inclusion was comparable in the two groups of subjects. After the flight there was an average score of 6.7 (SD 1.7) in the control group, while in the Venoruton group the score was on average 3 (SD 1.1) (p < 0.05). In the control group 77% of the subjects had an evident increase in ankle circumference and volume, which was clearly visible at inspection and associated with discomfort. In the Venoruton group, edema was clearly present only in 8% of subjects (associated with discomfort rated between 3 and 6 on the analogue scale line) and it was mild, not associated with symptoms. Therefore the control of flight edema with Venoruton was clear both considering parametric data (circumference and volume) and non-parametric (analogue scale lines) measurements. The combined evaluation of the edema score is significantly favorable for subjects under prophylaxis with Venoruton.