Duplex Ultrasound Assessment of Venous Reflux

In these reflux studies, the patient is required to stand on a platform which is very comfortable for both the patient and the operator. The patient is asked to stand on the leg which which is not being examined, the other one is highly bent at the knee and rotated externally. The examiner sits right in front, holding the probe in the right hand. For transducer selection you press the examination button on the console and you will have all the probes available on the screen, what you do is for these reflux you select linear probe and lower extremity vane. Press the set button, it will connect the transducer to the machine and it's ready to go. Once you've selected the probe, put gel on it. I have a nice good strip of gel on it. Once you've got the gel on it, place one hand behind the knee, second one with the probe on the medial aspects of the leg. Locate the long cephalus vein in transverse section once you have located you can either move up or down or turn your transducer longitudinally to take the measurements. Okay what you do is you put your transducer in cross section and locate the long syphilis vein in cross section. You play with the buttons so that you can optimize the image quality. You can increase or decrease the depth as necessary. Ideally your image should be in the center of your screen. Your brightness button is located on the right hand side, you can turn it up and down so that the vessel is clearly visualized on the screen. Once you have located it, you turn Once you have located it, you turn your probe longitudinally, adjust your control using the brightness and also your TCG. Once you are in beam mode you can adjust your brightness so that the image is clearly visible. Move up towards the sphenofemoral junction, increasing your depth because as it goes up it dives deeper. Now as you can see on the screen it merges with the femoral vein here. Now, femoral vein is in longitudinal plane, whereas saphenous vein is in cross-section. Now, what we're going to do here, we're going to turn the probe around into longitudinal plane, so we can get the long saphenous vein. Now here you can see the long cephalus vein coming around the corner, it's a nice bend here. Usually there is a valve here which gives rise to a reflux in this vein, so it's very important to take a reading as close to the junction, usually about a centimetre away from the junction. Now the long cephalus vein is relatively superficial to the deep vein. I'm going to decrease the depth to get rid of the deep system. All we have is long cephalosphere and the surface area going towards the junction. Now we're going to scan the vessel along in longitudinal plane. At this point, you can stop and take a Doppler signal to see whether there is a reflux or not. Once you have your vessel in view on the screen, you can see all these speckles passed through the vessel. Next thing we're going to do is put the color on. Now that's your color box and it needs to be angled correctly at 60, 45 to 60 degree. As you can see there is too much color bleed so we need to change the color setting, turn the colour again so that you have minimum bleed into the surrounding area. We are on the long syphilis vein near the junction, in longitudinal plane, as you can see very clearly the vessel here. The common practice is to grab hold of the calf muscle and give it a good squeeze. The idea behind that is you will expand all the venous blood in the calf muscle, it will go up into the vessel. If there is a reflux, you will see blood flowing in the opposite direction. The color flow on these machines indicate directional flow. Red goes one way and blue goes the other way. If there's a reflux, you will see both colors. If there's no reflux, there will be only one color. Right, now what we're going to do is we're going to squeeze the calf muscle and see. So you saw a red color followed by blue color indicating reflux. We are going to give it another go. Red and followed by blue. So presence of two colors one after the other indicates significant reflux in these vessels. There you go, once again, red and blue. The next thing after you have ascertained that there is reflux, you need to see how long the reflux lasts, so get some objective measurements. For this one, you put the switch on the Doppler, pulse wave, and you see this continuous flow. Right, we're going to give the calf muscle a good squeeze and look at the reflux. I can do it again. Okay. Alright, one more try, good squeeze. As you can see here, the downward trace is the blood going up into the long cephalus vein. Once we release the pressure on the calf muscles, there is a flow back down the leg, indicating quite significant reflux.