So, to recap Venous Physiology, lower extremity veins channel flow upwards against gravity and back towards the heart via a force generated by the Calf Muscle Pump. Vein valves, when functioning properly, block the flow directed back downward due to gravity’s relentless pull. Broken (or incompetent) valves account for much of the source of problems that lead to those troublesome varicose veins.
But, let’s take a step back for a moment and talk a bit about lower extremity vein anatomy. Don’t worry, it won’t be gross…I promise.
In very broad terms, there are two important venous systems in the lower extremities. The Deep Veins and Superficial Veins.
Deep veins handle the vast majority of flow out of the lower extremities. That is one reason why problems affecting the Deep veins can lead to profound discomfort and unhappiness.
Fortunately, Deep vein valve dysfunction isn’t so common. However, Superficial vein valve dysfunction (or Superficial Venous Insufficiency)…allowing wrong-way flow to move past broken valves and pool downwards toward the feet…is an incredibly common problem. More than 80 million Americans suffer from some form of venous disorder. 25% of women and 15% of men suffer from symptomatic varicose veins. Up to 55% of American women may be affected by vein disease during their lifetime.
Of all the factors leading to superficial venous insuffiency (SVI), the two most impactful seem to be genetics and pregnancies. A family history of vein disease can be a factor in over 80% of patients with varicose veins [so choose your parents wisely!]. Pregnancies can lead to a worsening of vein disease by at least a few mechanisms:
- There are higher levels of estrogen/progesterone in order to support the pregnancy. These hormones also happen to make the already stretchy veins even stretchier.
- There is a greater volume of blood in circulation to support both mom and baby. More volume leads to increased stretching of veins.
- There is a baby growing bigger by the day in mom’s pelvis; this can ultimately affect the flow trying to leave the lower extremities through the pelvis and back to the heart.Increased back-pressure also leads to stretched-out veins.
So…these factors and certainly others contribute to valves that fail to effectively block downward flow. This wrong-way flow is called Reflux. Superficial venous reflux or Superficial Venous Insufficiency (SVI) is what ultimately leads to excess venous pressure (venous hypertension) that builds up in the stretchy veins in the lower extremities.
If you think of the superficial venous system as a tree, there are bigger trunks, smaller branches (or tributaries) and finally tinier “leaves” at the surface. As pressure builds up in the trunks, it in turn gets transmitted to the smaller branches that live closer to the surface of the skin. Over time, the veins close to the surface may bulge out and become tortuously twisty. In addition, tiny branches at the surface may create patterns of spidery red and blue streaks.
Of all the veins in the superficial venous system (and there are many), the most common “culprit” trunks where SVI may develop are these “usual suspects”:
- The Great Saphenous Vein (GSV): The GSV starts collecting flow by the inner ankle and typically winds its way up the inner thigh and inner leg. Eventually this vein has its main interconnection and outflow to the Deep system by the crease in the groin.
- The Small Saphenous Vein(SSV): The SSV starts collecting flow at the outer ankle and winds its way vertically along the back of the calf [think of the lines that you’d see in those old-time silk stockings]. Ultimately the main interconnection/outflow to the Deep system is typically located somewhere at/just above/just below the back of the knee.
During your consultation appointment, if an ultrasound is deemed necessary, we will mainly be focusing on the function of the valves in those 2 veins on each leg.
Diagnosis of SVI is pretty straightforward. The best way to test how your valves perform under real-life conditions is to have you stand upright. Rather than chase you around the room and test what goes on when your calf muscle pump is in action, we can simulate this by keeping you still and gently squeezing your calf muscles. When I give a little squeeze, we send some flow upwards and watch this register on the ultrasound screen. Then I let go and your calf muscle pump relaxes. At this point we pay close attention to the screen and see how long the flow travels back downward before stopping due to valve closure. I can measure the exact amount of time it takes for flow to stop due to the fanciness of my ultrasound. Reflux lasting longer than 500miliseconds (or half a second…means the same thing) is considered to be abnormal.
Now that we have a diagnosis, we shouldn’t fret: SVI is not only an amazingly common problem, it’s also amazingly fixable! Well, let me qualify that a bit. As good as current technology is, we still lack the ability to fix broken superficial valves. However, what I can do is reroute flow to Superficial and Deep veins that have normal functioning valves…thus restoring normal flow out of the legs.
Learn more amazing facts about treating superficial venous disease by clicking here.