Presented by: Eri Fukaya, MD, PhD
Clinical Instructor, Vascular Medicine
June 9, 2016
The basic concept of how blood moves through the body has been observed since the days of Hippocrates, but it wasn’t until the mid-1600s that early scientists realized that the blood’s circulation was based on one interconnected framework.
The network of blood vessels that delivers oxygen and nutrients to the cells is composed of three interconnected systems: The arterial system includes arteries, the thick, muscular vessels that carry blood away from the heart; the venous system, made up of veins that bring blood back to the heart; and the lymphatic system, which removes the blood’s toxins.
Within the venous system there are superficial veins, which are located just under the skin, and deep veins, located in the muscles and along the bones. Veins are not as rigid as arteries, which allow them to dilate and expand. They are able to push blood back to the heart through a series of one-way valves that work like swinging doors that close up once blood is forced through. In the legs, these valves, along with muscles in the calf that contract and relax, push the blood against gravity and back toward the heart.
“Muscle contractions in your lower legs act as pumps, and the vein’s elastic walls help blood return to the heart,” said Eri Fukaya, MD, PhD, a clinical Instructor of vascular surgery, who spoke at a presentation sponsored by the Stanford Health Library.
Reflux and Pressure Problems
Venous disease reflux occurs when these small valves no long function properly, allowing blood to flow backward toward the foot. The flexible walls of the vein balloon outward so the valves do not close properly, causing blood to accumulate and pool in the legs. As a result, the vein tends to bulge and twist, causing a spider vein or varicose vein, depending on the size and location of the vessel. If the condition worsens, the vessel walls may develop chronic inflammation and sustain high venous pressure.
Symptoms of reflux can include dull aching pain, cramps, swelling, or sensations of itching, tingling burning, or throbbing. Advanced cases can lead to skin changes or ulcers.
Occasionally, veins deep within the legs become enlarged and develop a blood clot, a condition known as thrombophlebitis or deep vein thrombosis. The condition is serious since a clot can travel to the lungs, block a major vessel, and cause a pulmonary embolism. Deep vein thrombosis can cause leg pain or swelling, but may occur without any symptoms.
The causes of venous disease are not clearly defined, though there appears to be a genetic factor. Venous disease is more common in women and in people over age 50. Valve damage may occur as the result of aging, obesity, extended sitting or standing, or reduced mobility. Pregnant women often develop varicose veins, and the condition is more prevalent in professions that require long periods of standing, such as food servers, nurses, and factory workers.
Though there is no guaranteed way to prevent venous disease, it’s important to stay active and exercise to keep calf muscles strong. Walking is the best preventive activity, Dr. Fukaya said. Keep weight down, and avoid sitting for extended periods.
Diagnosis and Treatment
Diagnosis is usually done using duplex ultrasound, a noninvasive imaging technology that shows how blood is moving through the arteries and veins. During the exam, if the normally flexible vein does not collapse when pressure is applied, it could imply the presence of a clot.
The first line of treatment for reflux is compression; support stockings create an external scaffold on the legs, reducing pressure and improving calf muscle pump function to slow the progression of venous disease and ease symptoms. Dr. Fukaya suggested starting by using compression stockings or socks at 20 to 30 mmHg (the measurement of pressure) and moving slowly to higher compression.
The history of surgery for varicose veins goes back hundreds of years, and venous disease now can be treated on an outpatient basis with minimally invasive procedures. Endovenous ablation is a catheter-based procedure that shuts down the refluxing vein. Phlebectomy removes varicose veins through a series of tiny skin punctures with small surgical hooks. An option for smaller veins and spider veins is sclerotherapy, in which a solution is injected directly into the vein, which then scars, closes up, and eventually disappears. Newer and less invasive approaches continue to be explored and developed.
“Closing off a vein or part of vein is not an issue because blood will reroute its way back to the heart,” Dr. Fukaya said. “The deeper veins take care of the larger volumes of blood.”
Deep vein thrombosis is treated with blood thinners to prevent the clot from getting bigger or breaking loose and causing a pulmonary embolism. Anticoagulants like warfarin and heparin decrease the blood’s ability to clot but need to be monitored for possible side effects, she said. Novel anticoagulant (NOAC) drugs show promise as a new option.
Clots have historically been treated surgically using clamps or filters to prevent migration but with less than perfect results. Clinical trials for newer therapies such as catheter-based thrombolysis, which target the site of a blood clot and dissolve the blockage, are being explored to minimize long-term complications of post-thrombotic syndrome.
“We still don’t know why venous disease develops, but in the future we hope that genetics will provide a tool to home in on an underlying cause,” Dr. Fukaya said.
About the Speaker
Eri Fukaya, MD, PhD, is a clinical instructor in the Division of Vascular Surgery and a specialist in diagnosing and treating venous disease. She received her MD and PhD from Tokyo Women’s Medical University and completed a fellowship in vascular medicine at the University of Pennsylvania. She did a residency in internal medicine at Lankenau Medical Center in Pennsylvania and in plastic and reconstructive surgery at Tokyo Women’s Medical University. She joined the Stanford faculty in 2015.
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