Healthy leg veins contain valves that allow blood to move in one direction from the lower limbs toward the heart. These valves open when blood is flowing toward the heart, and close to prevent venous reflux, or the backward flow of blood. When veins weaken and become enlarged, their valves cannot close properly, which leads to venous reflux and impaired drainage of venous blood from the legs. Venous reflux is most common in the superficial veins. The largest superficial vein is the great saphenous vein, which runs from the top of the foot to the groin, where it originates at a deep vein.
Factors that contribute to venous reflux disease include female gender, heredity, obesity, lack of physical activity, multiple pregnancies, age, past history of blood clots in the legs and professions that involve long periods of standing. According to population studies, the prevalence of visible tortuous varicose veins, a common indicator of venous reflux disease, is up to 15% for adult men and 25% for adult women. A clinical registry of over 1,000 patients shows that the average age of patients treated for venous reflux is 48 and over 75% of the patients are women.
Venous reflux can be classified as either asymptomatic or symptomatic, depending on the degree of severity. Symptomatic venous reflux disease is a more advanced stage of the disease and can have a profound impact on the patient's quality of life. People with symptomatic venous reflux disease may seek treatment due to a combination of symptoms and signs, which may include leg pain and swelling; painful varicose veins; skin changes such as discoloration or inflammation; and open skin ulcers.
A primary goal of treating symptomatic venous reflux is to eliminate the reflux at its source, such as, for example, the great saphenous vein. If a diseased vein is either closed or removed, blood can automatically reroute into other veins without any known negative consequences to the patient.
The current non-invasive methods for treatment of reflux in the greater saphenous vein include radiofrequency (RF) ablation, laser endothermal ablation, and sclerotherapy, including foam sclerotherapy. Radiofrequency ablation and laser ablation require tumescent anesthesia which produce both bruising and pain along the inner thigh and upper inner calf for several weeks, and both can have side effects of burns and nerve damage. Radiofrequency ablation and laser ablation also require capital purchases of a radiofrequency device or laser box, often at costs of more than $50,000, in addition to expensive disposal mechanisms. While foam sclerotherapy is relatively non-invasive, it has a high rate of recurrence and potential side effects. All of the methods require wearing compression stockings for 2-4 weeks.
USPTO Backgrounds
USPTO Backgrounds