A small group of patients with a common heart defect who were treated for varicose veins with an injectable microfoam experienced no neurological, visual or cardiac changes as a result of the treatment, according to preliminary results from a phase II trial.
The results are being presented (March 17) in Washington, D.C., at the annual scientific meeting of the Society of Interventional Radiology (SIR).
Injectable foams are usually made by mixing a sclerosant, an irritant that causes damage to the vein wall and subsequent scarring, with room air. Sclerosant foams have been a standard treatment since 1997 for spider veins and small varicose veins. Varisolve, a foam made with carbon dioxide, is relatively painless compared to other sclerosants, which can cause burning, said John D. Regan, M.D., clinical director of the Interventional Section in the Department of Radiology at Wake Forest University Baptist Medical Center.
Veins in the leg have valves that are designed to prevent blood from flowing backward as it returns to the heart. Varicose veins are caused by weakened valves (commonly in the great saphenous vein, the large vein running up the inner side of the leg) which allow blood to flow backward and pool in the veins in the leg. The resulting high pressure causes veins to expand like balloons and become tortuous or twisted. The latest treatments involve blocking the great saphenous vein (GSV) to prevent the backflow, called reflux. The Varisolve foam injection procedure is a less invasive alternative to surgical techniques and intravenous techniques that close the vein with radiofrequency ablation or laser energy.
Although any air-based foam carries a theoretical risk to the patient because of the insolubility of air in the blood, the risk is small, said Regan, the presenting author of the phase II trial's preliminary results. "We believe that the carbon-dioxide-based foam used in Varisolve will be totally safe due to the small size of the bubbles, the consistency of the foam and the solubility of carbon dioxide."