Before approaching the clinical part of this discussion, I will devote a few paragraphs to how venous blood flows in the legs. It starts by recognizing the simple problem of the venous circulation. When blood gets to the end of its trip in the capillary it has no more energy or push left to return it home. Now, that is easy for blood in the head or shoulder. Gravity will pull the blood back home to the heart. But leg blood has a difficult problem, it has to swim upwards against gravity to get home to the heart.
The interaction between the muscles of the legs and the veins is complex. The muscles of the legs actually push or squeeze the blood flow upward towards the upper body. The large leg veins have valves that prevent any blood from falling backwards when the leg muscles relax. Any blood that has been pumped upwards is prevented from falling back downward away from the heart by the valves.
This elegant system can fail for two reasons. Firstly, the leg muscles can stop moving as in a stroke, or when a cast is put on the leg or when restricting a patient to bedrest such as after surgery. In these cases there is not enough force from the legs to push the blood upwards.
The second, more common reason is that a little recognized set of veins starts to leak. The legs have a set of veins running in between the muscle and the bone and a parallel set of veins rising outside the muscle under the skin. These two systems of veins that carry blood back towards the heart are connected by small “perforator veins” that run from inside the center of the leg to the skin. When these perforator veins start to leak, extra blood gets diverted to the veins under the skin and they must deal with much higher blood flows than they were designed for. This causes the large veins that bring blood up towards the heart to expand. When they get large enough the valves no longer seal the veins and these large under skin veins leak blood backwards down towards the foot. The process becomes a self-perpetuating destruction where the increasing leaks increase the vein size which further destroys the valves and further increases the leak.
At this point the leg veins become very large and noticeable and the ankle starts to become bloated or what we call edematous. The edema is a result of the leaky valves. But it is also one of the body’s corrective mechanisms to increase the pressure at the bottom of the leg to force blood back up towards the heart. The pressure is generated by the skin and fascia pressing on the edema which forces blood upwards. Unfortunately, the edema presses back against the skin and fascia and stretches them. With the passage of time the skin and fascia lose their strength and the leg gets more swollen.
This is a bad outcome because besides the unsightly and uncomfortable swelling, the edema causes three important medical problems that will cause harm and require attention. .
The first problem is that edema makes leg infections called cellulitis much more common. This infection can be a nuisance for some people requiring a few days of rest and antibiotics. But for other people the infection can lead to hospitalization and life-threatening sepsis.
The second medical problem generated by edema is an increase in blood clots in the leg veins. This condition is called thrombophlebitis. Beside the pain, this condition sometimes showers the lung circulation with blood clots leading to very serious and frequently life-threatening pulmonary emboli.
The third medical problem occurs when the edema causes the skin to break down and form ulcers. These are painful and can lead to infections that burrow down as far as the bone and lead to prolonged courses of antibiotics and rarely even amputations. The ulcers require meticulous daily medical care to get them to heal. The edema causes pressure on the skin layers and interferes with healing.
The simplest, and some authorities believe the only way to rectify this situation is to press back against the edema. This is usually done with elastic stockings. Although wildly unpopular with patients, they are very successful when patients will wear them every day. They have to be the correct size for each individual patient and should be purchased in stores with special expertise and diverse inventories.
There are other approaches. Some individuals insist on using elastic bandages. I have never yet met a patient who can apply them correctly and I have never met a patient for whom they succeed. There are pumps for the edema which can be used but require a great deal of time and effort. The use of water pills to eliminate the extra fluid is very rarely successful and frequently harmful because the fluid in the legs does not mobilize easily to get to the kidneys.
There are a large number of surgical approaches to eliminating varicose veins. The use of these techniques is very controversial. They are definitely required for some patients but there is great disagreement whether these patients are a large group or a small group on the fringe with rare indications.
The surgical approaches are definitely successful cosmetically for at least a limited time. They would be more successful if the surgeons would tie off the leaky perforator veins but in practice this is done by only a small number of surgeons. When the surgical approach is completed all patients are instructed to wear the elastic stockings for life. This of course suggests that if the stockings succeed alone, the surgery is extraneous.
More recently the surgery and laser ligation on the vein are performed by interventional radiologists and surgeons who place wires and catheters in the veins and occlude them or stent them to produce the desired result
Of course, patients who have complications of the edema like cellulitis, or thrombophlebitis need the specific medications and local care for each condition. But at the end to prevent recurrences the stockings are necessary. In fact, patients who wear proper elastic stockings every day almost never have a recurrent clot or infection.
It cannot be said too often that the earlier the stockings are worn the better the results. Because the stretching of the veins and the skin and fascia by the edema is a progressive process, the sooner the weakening veins are supported by the elastic stockings the less deterioration takes place in the leg itself. With the leg in better condition the complications of poor veins and edema become less common.
Comments