Some Resources on ChronicVenous Insufficiency

Below are excerpts from resources on the evaluation of chronic venous insufficiency. I did this research in response to questions about the topic from a friend with chronic insufficiency.

http://emedicine.medscape.com/article/1085412-overview

“Magnetic resonance venography (MRV) is the most sensitive and specific test for the assessment of deep and superficial venous disease in the lower legs and pelvis, areas not accessible by means of other modalities. MRV is particularly useful because it can help detect previously unsuspected nonvascular causes of leg pain and edema when the clinical presentation erroneously suggests venous insufficiency or venous obstruction.C

“Photoplethysmography uses infrared light to assess capillary filling during exercise. Increased capillary filling is indicative of venous reflux and, consequently, of incompetent veins.

“Outflow plethysmography involves placing and subsequently releasing a tourniquet on the lower extremity; the veins should quickly return to baseline pressures. Failure to do so indicates reflux”

Using photoplethysmography to assess for venous insufficiency and screen for deep vein thrombosis (DVT): A review of the literature on the use of photoplethysmography (PPG) as an assessment tool to identify the presence of venous insufficiency and in screening for DVT—available at

http://www.huntleigh. co.uk/diagnostics/Admin/files/20081027112959.pdf                     Data is not that good the article suggests.

Outflow plethysmography No useful articles found on google.

Venous Refilling Time

“The VRT is the time necessary for the lower leg to become suffused with blood after the calf muscle pump has emptied the lower leg as thoroughly as possible. When patients with healthy veins are in a sitting position, venous refilling of the lower leg occurs only by means of arterial inflow and requires at least 2 minutes.

“In patients with mild and asymptomatic venous insufficiency, some venous refilling occurs by means of reflux across leaky valves. These asymptomatic patients have a VRT of 40-120 seconds.

“In patients with significant venous insufficiency, venous refilling occurs through high-volume reflux and is fairly rapid. An abnormally fast VRT of 20-40 seconds is recorded, reflecting retrograde venous flow through failed valves in superficial or perforating veins. This degree of reflux may be associated with the typical symptoms of venous insufficiency. Patients often complain of nocturnal leg cramps, restless legs, leg soreness, burning leg pain, and premature leg fatigue.

“A VRT shorter than 20 seconds is markedly abnormal and is attributable to high volumes of retrograde venous flow. High-volume reflux may occur via the superficial veins, the large perforators, or the deep veins. Patients with this degree of reflux are nearly always symptomatic. When the VRT is shorter than 10 seconds, venous ulcerations are so common as to be considered virtually inevitable.”

The article chronic venous insufficiency, 2005, Circulation: article available at http://circ.ahajournals.org/content/111/18/2398.full.pdf. p 2403 describes the technique of venous refilling time and:

The VRT is the time necessary for the lower leg to become suffused with blood after the calf muscle pump has emptied the lower leg as thoroughly as possible. When patients with healthy veins are in a sitting position, venous refilling of the lower leg occurs only by means of arterial inflow and requires at least 2 minutes.”

“In patients with mild and asymptomatic venous insufficiency, some venous refilling occurs by means of reflux across leaky valves. These asymptomatic patients have a VRT of 40-120 seconds.”

“In patients with significant venous insufficiency, venous refilling occurs through high-volume reflux and is fairly rapid. An abnormally fast VRT of 20-40 seconds is recorded, reflecting retrograde venous flow through failed valves in superficial or perforating veins. This degree of reflux may be associated with the typical symptoms of venous insufficiency. Patients often complain of nocturnal leg cramps, restless legs, leg soreness, burning leg pain, and premature leg fatigue.”

“A VRT shorter than 20 seconds is markedly abnormal and is attributable to high volumes of retrograde venous flow. High-volume reflux may occur via the superficial veins, the large perforators, or the deep veins. Patients with this degree of reflux are nearly always symptomatic. When the VRT is shorter than 10 seconds, venous ulcerations are so common as to be considered virtually inevitable.”

Ejection Fraction

“The ability of the calf muscle pump to eject blood is determined after a single and 10 repetitivecontractions during toe raises. The volume of blood ejected with1 tiptoe maneuver divided by the venous volume is the so-calledejection fraction. Complications of CVI, such as ulceration, have been shown to correlate with the severity of reflux assessed with the venous filling index and ejection capacity.32,42,44 This technique provides quantitative information about several aspects ofglobal venous function. It may be used in the selection of intervention and assessment of the response to intervention.46,47″

Calf Muscle pump dysfunction in severe chronic venous insufficiency 2004 available at http://www.phlebolymphology.org/wp-content/pdf/Phlebolymphology47.pdf

Everyone dealing with practical phlebology will be convinced that, in patients with chronic venous disease, the insufficiency of the venous pump is caused not only by valvular damage and hindrances to venous backflow, but also by muscular dysfunction. However, it is not easy to differentiate these components by clinical testing. There are published data showing that are striction of ankle movement, which is a frequent sequel of painful leg ulcers, leads to a reduction of the venous pumping capacity. Muscles that are not trained will become atrophic and therefore the motor of the venous pump will fail.”

In his article, Dr Simka from Poland, discusses a plethysmographic method to evaluate  whether measurements in the supine and standing position could determine the motor component of the venous pump. In this short paper, no methodological details are given and the results are only reported in terms of “percentage insufficiency” and not in absolute terms characterizing the efficiency of the venous pump. Therefore, it seems unlikely that his method will solvethe problem.

 Article on calf muscle pump function, The Influence of Calf Muscle Function and Venous Function in Patients with Chronic Venous Insufficiency 2001 full text at http://fulltext.ausport.gov.au/fulltext/2001/acsms/papers/YANG1.pdf

 YouTube has an interesting video on the Geko device to improve calf muscle pump function.

http://www.youtube.com/watch?v=K3sW5QeLyiw&feature=relmfu

Maximum venous outflow

“MVO testing is performed to detect an obstruction to venous outflow from the lower leg, no matter what the cause. Its results are a measure of the speed with which blood can flow out of a maximally congested lower leg when an occluding thigh tourniquet is suddenly removed.”

“A major advantage of MVO testing is that as a functional rather than anatomic test, it is sensitive to significant intrinsic or extrinsic venous obstruction due to any cause at almost any level. It can be used to detect obstructing thrombus in the calf veins, the iliac veins, and the vena cava, areas where ultrasonography and venography are insensitive. It can also be used to detect venous obstruction due to extravascular hematomas, tumors, and other extrinsic disease processes.”

“The main disadvantage of MVO testing is that it is sensitive only for significant venous obstruction and not for partial obstruction. It is not useful for the detection of reflux-induced venous insufficiency. A normal MVO result does not absolutely rule out DVT.”

Muscle pump ejection fraction

“The MPEF test is used to detect failure of the calf muscle pump to expel blood from the lower leg. Its results are highly repeatable, but a skilled operator is required to obtain clean, meaningful tracings.”

“The patient is asked to stand on his or her tiptoes 10-20 times or to dorsiflex his or her ankle. The change in a physical parameter that reflects the blood volume in the calf is recorded as the calf muscle is pumped.”

“In patients with normal veins and a normal calf muscle pump, 10-20 tiptoe motions or ankle dorsiflexions empties the venous capacitance circuit of the calf. In patients with muscle pump failure, severe proximal obstruction, or severe deep venous insufficiency, tiptoe motions or ankle dorsiflexions have little or no effect on the amount of blood remaining in the calf. Venous insufficiency due to this cause is difficult to treat”

These are questions that I suggested my friend might ask the doctor  about possible treatments

Ask the doctor if a sequential compression device might help relieve pain. For example, the Bio Compression four chamber sequential compression device for example see:

http://www.biohorizonmedical.com/bio-compression-2004-pneumatic-compression-device

Ask if TENS unit could be used for chronic venous insufficiency pain relief or for peroneal nerve stimulation to stimulate calf muscle pump—There are devices available in Europe that are not approved in the US (Geko). See http://gekodevices.com/en-uk/studies-trials/neuromuscular-electrostimulation-dvt-prophylaxis-nmes-studies-and-trials/blood-supply-augmentation-in-the-leg/ .

 

 

 

 

 

 

 

 

 

 

 

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