New Treatment Option for Primary Venous InsufficiencySymptomatic venous insufficiency and varicose veins remains a clinical challenge for physicians to manage. Traditional treatment regimens including leg elevation, exercise, venous compression stockings, and drugs, such as pentoxyfilline, are usually insufficient long term options for patients. Recent advances in interventional radiology techniques, however, are improving the prognosis of this disease. This issue of Imaging Update discusses primary venous insufficiency and treatment using the endovascular Closure ® catheter (VNUS Medical Technologies, Inc.). Incidence and Pathophysiology The primary venous insufficiency (PVI) affects 10-15% of men and 20-25% of women. There is a familial tendency toward development of varicose veins. Female hormonal influences, i.e. progesterone, have a significant affect on the veins. When varicose veins develop in pregnancy, 70-80% of cases develop in the first trimester and is not dependant of the size of the uterus. Varicose veins are classified as primary or secondary, depending on the site of valvular compromise. In primary varicose vein disease, incompetence originates in the superficial venous system, which is the topic of this discussion. Superficial venous incompetence is the end result of persistent high pressures into veins that were intended for low pressure. This high pressure causes the veins to dilate whereby the valves can no longer maintain apposition. In secondary varicose vein disease, incompetence arises in the deep venous system, usually because of prior thrombosis. In either case, unidirectional control of the blood flow is lost. Primary venous insufficiency resulting in varicose veins usually is not only a cosmetic problem for the patient. Because of the chronic pooling of blood, patients typically complain of leg pain, leg fatigue, ankle edema, hyperpigmentation, and superficial thrombophlebitis. Diagnosis Ultrasound has become the mainstay diagnostic tool for assessing the quantity and severity of venous insufficiency. Gray scale, i.e. the cross sectional images, allows direct identification of the dilated veins and any tributaries. Doppler analysis provides physiologic information regarding the degree of reflux. The techniques used to measure reflux include Valsava and compression. Treatment Conservative Therapy All patients with venous disease may benefit from conservative measures designed to decrease distension and reduce ambulatory venous hypertension. Exercise of the lower extremities, activates the musculovenous pump, primarily comprised of the foot and calf muscles, and causes the blood to be expelled from the leg veins toward the heart. Because the full contraction of the muscles involved in pumping the venous blood to the heart requires ankle flexion, the wearing of high heels may reduce venous emptying and cause leg aching or tiredness. Raising the feet above the level of the heart for 15-30 minutes several times per day may reduce symptoms and edema. Elastic compression stockings may reduce the symptom severity and retard disease progression. By interfering with leukocyte activation, pentoxyfilline may prevent or reduce skin changes due to venous disease. Surgery Definitive treatment of the primary venous insufficiency involves removing the malfunctioning saphenous vein from the circulation. Traditional surgical options include saphenofemoral junction ligation, saphenous vein stripping, and sclerotherapy ablation. However, these procedures can cause a long recovery, bruising, and tenderness. As a result most people with varicose veins do not seek treatment. In 1999, for example, of an estimated 25 million sufferers only 150,000 vein strippings were performed in the U.S. Radiofrequency (RF) Ablation Catheter directed endovenous delivery of radiofrequency energy to ablate the malfunctioning saphenous vein is a recently developed alternative to traditional surgery. The Closure ® catheter (VNUS® Medical Technologies, Sunnyvale, CA) is one such system that has been FDA approved since 1999 and is the most frequently used in the U.S. and western Europe.
The RF generator delivers a constant amount of energy to the vein wall with continuous monitoring of the electrical and thermal effects on the vein. The procedure is typically outpatient. Under local tumescent anesthesia, a dermatotomy is made below the knee to accommodate either the 6 or 8Fr catheter. Bipolar electrodes at the end of the catheter maintain contact with the diseased vein wall.
Delivery of RF energy via the specially designed electrodes causes resistive heating of the vein wall resulting in vein shrinkage and occlusion. As coagulation of tissue occurs, there is a decrease in impedance that limits heat generation. Each catheter possesses a thermocouple to measure electrode temperature and provide feedback to the RF generator. The catheters are designed with flexible electrodes, which allow the target vessel to collapse around the catheter as the vein shrinks. The unique insulated electrode design limits the depth of thermal penetration. The catheter is slowly pulled back to treat the entire diseased vein.
Once the diseased vein is closed, blood is redirected toward healthy veins for blood emptying. The catheter is removed and hemostasis is obtained by manual compression. The leg is wrapped for typically 1 day to aid healing. Most patients resume normal activity in 1-2 days. Adverse affects are minimal, but at 6 months can include DVT (worldwide 0%, US 0%), skin burns (world wide 0%, U.S. 0% ), phlebitis (world wide 2%, U.S. 0%), and parasthesias (world wide 5%, U.S. 1%). These low rates are related to the method of tumescent anesthesia. Technical success rates are 98%. The saphenous vein remains occluded 90% of the time at 12 and 24 months. Patient satisfaction is routinely achieved, with 98% of patients indicating a willingness to recommend the RF procedure to a friend or family member. Contraindications include patients with a pacemaker or defibrillator, thrombus within the vessel, veins greater than 12mm in diameter, and patients with peripheral arterial disease (ABI < 0.9). Conclusions Primary venous insufficiency is a common disease that is often difficult to manage. Removal of the saphenous vein from the circulation is a primary part of definitive therapy. Use of radiofrequency energy allows for total coagulation of the vein with a decrease in post-operative discomfort and rapid patient recovery. Dear Colleagues: At Hawaii Radiologic Associates, Ltd., we are continuously trying to bring enhanced care through advanced technology to the patients of the Big Island. We would welcome the opportunity to discuss this exciting new treatment option with you and your patients. Both Medicare and HMSA reimburse this procedure. Patients may be scheduled by calling the Women’s Imaging Center (WIC) at (808) 961-4745 where initial screening consultation will be performed. This will include history, physical examination, and US screening of the symptomatic leg(s). Appropriate patients will then be rescheduled for the outpatient procedure at the WIC. The procedure typically takes one hour. A scheduled follow-up consultation and US will then be obtained in 1 week. References:
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