Validation of the Supine Venous Pump Function Test: A New Non-Invasive Tool in the Assessment of Deep Venous Insufficiency

Abstract

1. A new non-invasive test was developed to assess calf muscle pump function: the supine venous pump function test. The technique uses strain-gauge plethysmography and is performed in the supine position. The method is superior to other non-invasive methods because basically the most essential haemodynamic parameter, venous pressure decrease, is used by properly converting venous volume measurements into venous pressure. The validity of this test was established by comparison with invasive venous pressure measurements and by determining the reproducibility. Additionally, normal values were determined. 2. In 28 extremities the supine venous pump function test was performed simultaneously with invasive venous pressure measurements. The reproducibility of the test was assessed in 10 randomly chosen volunteers. In 34 volunteers normal values were obtained and 26 patients with clinical venous insufficiency were examined. 3. Comparison of the two methods revealed a correlation coefficient of r = 0.98 (P < 0.001). A mean difference of 3.9%pf between both methods was found with limits of agreement of -6.3%pf to 14.1%pf. The coefficient of repeatability was 13%pf and the coefficient of variation was 9%. The normal range was found to be > 60%pf. The mean pump function in the patient group was 45%pf. 4. The limits of agreement are small enough to be confident that the supine venous pump function test can be used instead of invasive venous pressure measurements to assess calf muscle pump function in clinical practice. The reproducibility of the test is good.

The effect of electrical stimulation on leg muscle pump activity in spinal cord-injured and able-bodied individuals

“…The tubes were stretched around the lower leg, 1±2 cm below the origin of the Achilles tendon, which is about 10 cm above the lateral malleolus. This placement is chosen in order to reduce the noise that can occur because of the contractions and, therefore, to obtain the best prediction of MPA (Janssen et al 1996).…”

“…The protocol used in this experiment was based on the supine venous pump function test, as used in the Clinical Vascular Laboratory of the University Hospital St. Radboud (Nijmegen, The Netherlands) to assess the degree of venous insuciency in patients (Janssen et al 1996). In the test, dorsal¯exion and tiptoe movements were rhythmically performed against the pressure produced by in¯atable cus around the thighs while volume changes were measured by strain-gauge plethysmography.…”

“…In the test, dorsal¯exion and tiptoe movements were rhythmically performed against the pressure produced by in¯atable cus around the thighs while volume changes were measured by strain-gauge plethysmography. The validity of this supine venous pump function test was established by Janssen et al (1996), who compared the test with invasive venous pressure measurements as being the gold standard. Comparison of the two methods showed a correlation coecient of r 0.98 (P < 0.001) with a mean dierence in pump function of 3.9%.…”

“…Strain-gauge plethysmography is a simple, non-invasive method for identifying volume changes of the limbs based on vascular activity (Brakkee and Kuiper 1982;Janssen et al 1996;Pointel et al 1981). Straingauge plethysmography has also been used to assess muscle pump function in healthy individuals (Janssen et al 1996;Rosfors 1991;Stick et al 1989;Struckman and Mathiesen 1985) as well as in clinical settings for patients with venous insuciency (Janssen et al 1996;Van Gerwen et al 1992).…”

“…Straingauge plethysmography has also been used to assess muscle pump function in healthy individuals (Janssen et al 1996;Rosfors 1991;Stick et al 1989;Struckman and Mathiesen 1985) as well as in clinical settings for patients with venous insuciency (Janssen et al 1996;Van Gerwen et al 1992). It has, however, never been used to study MPA during ES of the leg muscles in SCI individuals.…”