Perforator veins are an important part of the venous system. They connect the superficial
veins underneath the skin to the deep veins, which lie within the muscle compartment of
the leg. A fibrous layer called the fascia separates the deep veins and the superficial
veins and the perforator veins are so-called because they cross this layer through small
perforations. The normal direction of flow in these perforator veins is from superficial
to deep that is inwards. Some degree of outward flow is common even in healthy legs but it
is usually limited to less than 350 milliseconds. Because this outward flow of 350 milliseconds
duration is very short, as well as the fact that other superficial veins have a cut-off
value of 0.5 of a second to define significant reflux, most specialists use a duration of
greater than 0.5 of a second as indicating perforator reflux. Reflux is the most common
condition to affect the perforator veins and in this episode Michelle Moore demonstrates
the correct positioning of the patient, a standardised sequence to the conduct of the
examination, the key anatomical landmarks and she once again emphasises the key points
in optimisation of the image and flow settings of the ultrasound equipment. If you would
like to have a transcript of this video with explanatory notes, please send me an email,
the address is below and it is repeated at the end of this episode. Please be sure to
state which episode notes you wish to receive. We are no going to now have a look at the
calf to assess for any calf perforators. Occasionally you’ll find no incompetence of the long
saphenous nor short saphenous vein and there may well be just a single calf perforator
leading to troublesome varicose veins. So we’re going to start in transverse position.
So here we can see the tibia bone and the fascia between the deep and superficial planes.
This is our distal long saphenous vein, which is relatively normal in size. We can see one
of the branches which left the long saphenous vein at the level of the knee which traverses
around to the posterior calf. We can follow that down and again it re-enters the long
saphenous vein distally. So coming along the edge of the tibia we can pick up a small para-tibial
perforator. We’re going to visualise that better by reducing the depth on the machine
and moving our focal zone to the region of interest to obtain the most information. We
can take a diameter of the perforator as it travels through the superficial fascia. We’re
looking at 4 ½ millimetres. And again as we saw previously we need to check the competency
of that perforator so see whether it is actually significant. And to do that we are going to
angle again to the level of the vessel walls ensuring that the angle is less than 60 degrees.
We are going to reduce our frequency to ensure that slow flow within that vein is adequately
detected. And again, good squeeze just distal and release. So we can see we have a short
little burst of incompetence but again less than 0.5 second and not significant. As a
guide to checking the calf perforators we keep the tibia in view we can assess through
any para-tibial perforators and coming more medial this would be any Cockett perforators
coming in on the medial calf. Any perforators are identified. A good way to indicate to
the surgeon the level of the perforator is to take a ruler, to place that on the medial
malleolus and to measure to the level of the perforator and that can tell them, if surgery
is needed, exactly what level they are going to find the perforator, which in most cases
is not visible on top of the skin. So we also check for any lateral calf perforators. If
I just get you to turn your leg in for me, that’s great. More jelly. And again we’re
looking for any perforation through the superficial fascial layer. We’re most commonly looking
at the area where the muscle joins, just sweeping up and down the calf and we can see we have
no lateral calf perforators for David. And then we are just going to check the posterior
calf. Just turn your leg out again for me David, that’s great. As we saw previously,
we do have a posterior calf perforator where we would measure from the posterior knee crease
distally, but we have already assessed that that vein demonstrated insignificant level
of incompetency. And therefore isn’t significant. OK thank you all done.