By Jessica Ross for Veins1
Dr. Charles McCollum and colleagues at Wynthenshawe Hospital of Manchester, UK, represent a growing trend in varicose vein research: the revitalization of foam therapy. A variation on the more traditional [chemical] sclerotherapy, the use of foam injections to alleviate varicose veins was actually introduced decades ago in Europe, during the early 1940s. This avenue for research stayed relatively dormant until recent years, when foam therapy reemerged as an area for scientific research. These clinical studies have resulted in a refinement of technique that could ultimately drive foam therapy to the forefront of varicose vein treatment methods.
Often hereditary, varicose veins occur in 20% of the adult population and are most prevalent in older women. In general, veins function to return blood to the heart. Systemic veins, such as the ones in our legs, return deoxygenated blood to the heart. Deoxygenated blood appears blue. The pressure of blood in veins is usually low but must be sufficient to overcome the influence of gravity on blood. Veins have valves that normally prevent the back flow of blood. Over time, veins can distend or widen and the valves may become incompetent. Pregnancy, obesity and blood clots are examples of conditions that increase venous pressure and promote the development of varicose veins. Incompetent valves result in the backward flow of blood and pooling of blood in segments of veins. With time, these veins enlarge, become tortuous or twisted and become more visible under the skin. Because leg veins carry deoxygenated blood, they appear blue. For some, varicose veins merely constitute a cosmetic problem. However, many people experience symptoms due to varicose veins. Varicosities may become clotted, inflamed, and/or lead to chronic skin inflammation (stasis dermatitis) and leg ulcers.
The traditional treatments for varicose veins include elevating the legs and using compression stockings to more invasive procedures such as traditional (chemical) sclerotherapy or vein stripping. In chemical sclerotherapy, small or medium varicose veins are injected with a solution that scars and obstructs the "problem" vein(s), forcing the blood to develop new, better functioning pathways. Vein stripping removes long, problematic veins through a series of small incisions, creating similar circulatory detours. These treatments can be effective but are also associated with adverse events. Sclerotherapy may cause skin and tissue death, nerve injury, allergic reactions, infection, and blood clots, among other complications. Potential complications of vein stripping include nerve injury, infection, and the risks associated with anesthesia.
Laser therapy is available to treat some abnormalities of very superficial veins. However, this approach is not usually beneficial in the treatment of large varicose veins of the legs.
Traditional sclerotherapy utilizes a liquid agent to treat the veins. Once injected, some of the solution may be transported via blood away from the varicosity. Foam injection is an approach that overcomes this problem. After local anesthesia is administered to the patient, the vein is visualized with an ultrasound device. Foam containing the traditional chemical sclerotherapy agents (such as sodium tetradecylsulfate) with a significant portion of oxygen, is injected into the vein. Unlike sclerotherapy solutions, foam tends to remain at the injection site. The foam contains pockets of oxygen. As the foam forces blood out of the problem vein, the oxygen pockets simultaneously dissolve into the bloodstream, causing the vein to deflate and lie flat.
The results of several recent clinical studies have further reinvigorated this foam therapy renaissance. In one such study, an Italian team conducted a 3-year study of 453 patients, who all received sclerosing foam for large, medium or small varicose veins (Frullini A, and Cavezzi A, 2002). The authors found success rates of 88.1% and 93.3% for two variations of foam employed, and even more significantly, observed very low incidence of major complications. Similarly, an early 2004 New Zealand study reported that, “foam sclerotherapy is effective in treating varicose veins with high patient satisfaction with results and improvement in quality of life.” (Barrett JM, et al., 2004). In turn, the McCollum group at Wynthenshawe Hospital plans to further verify the safety of the foam method and will employ ultrasound technology to ascertain the biological fate of these critical, numerous oxygen pockets.
Short-term complications of foam therapy are similar to those of traditional sclerotherapy. Studies evaluating the long term effectiveness and safety of foam therapy are in progress.
Ultimately, this revitalization in foam sclerotherapy research represents a new direction in varicose vein therapy that will hopefully result in a low risk, yet highly effective, treatment option.