Exploring The Potential Of Procedures That Address Venous Ulcer Etiology
The complexity of venous ulcerations leads to prolonged healing and doubt. Clinicians have traditionally treated venous wounds with debridement, multi-layer compression dressings and skin grafts. Most of the literature focuses on various topical ointments, the use of allogenic grafting, compression therapies, etc. Unfortunately, there is little research on addressing the etiology of venous wounds. Understanding and treating the etiology in all aspects of medicine is imperative in order to achieve a successful result. Venous insufficiency is a condition in which veins do not adequately return blood back to the central system. In the lower extremity, both the superficial and deep vein systems of the legs utilize valves to ensure cephalad flow. The deep vein system also uses muscular contraction to assist in pumping the blood upward. A perforating vein is a vein that penetrates a fascial plane and may connect the superficial venous system to the deep vein system or connect greater saphenous veins to small saphenous veins. Over time, various risks factors such as heredity, hormones, pregnancy and prolonged standing cause the smooth muscle in the vein’s wall to relax. When this occurs, there is an inability of the vein valves to approximate. In the legs, the normal flow opposes gravity. However, with insufficiency, the blood refluxes and backflow occurs to the ankles. In severe cases, blood pooling leads to edema, hyperpigmentation, loss of skin turgor and ulceration. An ulcer can also occur after a varicose vein opens and causes bleeding. Consider a patient who presents with a venous ulceration. In most cases, these patients receive wound care and compression therapy. One does not usually perform an ultrasound. Ultrasound is crucial in finding out where the insufficiency lies and which veins lead to the ulceration. It is imperative that the physician or registered vascular technician evaluates both the deep vein and superficial vein systems for reflux. Just scanning the deep vein system for a thrombus would be incomplete and will not identify the pathology involved. Direct attention to the lower extremities while the patient is standing. Evaluate the deep vein system, including the femoral, popliteal, tibial and peroneal veins, and look for the presence of a thrombus and reflux. In the superficial system, test the greater and small saphenous veins as well as anterior and posterior circumflex and perforating veins. In general, one should utilize the following guidelines to identify insufficiency in the superficial system: a greater saphenous vein larger than 0.4 cm in diameter, longer than 0.5 seconds of reflux and a small saphenous or perforating vein larger than 0.3 cm in diameter and 0.5 seconds of reflux. If varicosities are present, one can follow the varicosities towards their tributary. This is called vein mapping. With the presence of a venous ulcer, the ultrasonographer will be able to scan over the ulcer and trace it back to the insufficient vein. The ulcer is usually a direct extension from a superficial varicosity. However, the underlying etiology is a result of insufficiency of the superficial, deep or perforating vein system. By addressing the insufficient vein either through ultrasound guided chemical ablation or endovenous ablation, venous ulcerations heal on an average of four weeks barring that no infection is present.
Key Insights On Ultrasound Guided Chemical Ablation
Ultrasound guided chemical ablation is a treatment in which one injects a sclerosant into the refluxing vein. The two most common sclerosants are sodium tetradecyl sulfate (Sotradecol, Angiodynamics), which recently received FDA approval, and polidocanol (Asclera, Merz). Traditional saline injections are not strong enough to treat large veins and should be reserved for cosmetic spider and reticular veins only. With ultrasound guidance, inject liquid sclerosant or foam sclerosant (sclerosant mixed with air or CO2) into the insufficient vein. Foam has become widely accepted for its advantages. Foam solution makes more contact with the vein wall due to increased surface area properties, disperses quicker and stays in the vein longer than liquid. Furthermore, one can easily visualize and follow the solution on ultrasound during treatment. With sclerotherapy treatment, the chemical damages the vessel wall. The vein hardens and the body breaks it down. Larger and deeper veins will harden, thicken and shrink but may not disappear altogether. One does not directly inject the ulceration but rather the insufficient vein along its course. If one performs ultrasound chemical ablation alone, it will take a few treatments before treatment addresses the veins at the ulceration site. Accordingly, this method usually occurs after an ablative procedure. Only perform this treatment on the superficial and perforating vein systems. Do not inject the deep venous system.
A Closer Look At Endovenous Laser Ablation
Endovenous laser or radiofrequency ablation is a procedure that closes the long segment of the insufficient vein. First access the insufficient vein under the guidance of ultrasound. Through the access needle, insert a guide wire. Remove the needle and place a dilator and sheath over the wire and into the vessel. Remove the wire and the dilator, and leave the sheath in the vein. Proceed to instill a fiber optic laser or catheter for radiofrequency. Confirm the placement of the fiber or cathode exiting the end of the sheath. Be sure to avoid superficial/deep vein junctions by at least 1.5 inches. Then deliver anesthetic agents mixed with saline, creating what is known as a sea of tumescence. After administering adequate anesthetic, remove the sheath along with the laser and/or catheter while delivering laser energy or radiofrequency. One must apply enough laser energy or radiofrequency to the vein in order to create appropriate closure and stop the flow through the insufficient portion. After the procedure, the patient wears compression stockings and bandages over the ulceration for approximately one week. Follow-up with the patient includes the use of post-procedure ultrasound to confirm the success of the procedure (namely ensuring there is no deep thrombus) and mapping the vein to the ulcerated site. Perform traditional debridement and have the patient wear compression dressings for two weeks. After the two-week period, if the ulceration has not already healed, ultrasound guided chemical ablation may close any remaining branches of veins that have reflux flow. Do not inject sclerosant directly through the ulceration. It is imperative to treat any and all vessels leading to the ulceration but it is not necessary to treat all superficial vein structures if insufficiency is not present. Over the course of therapy, the ulceration will decrease in size and the vessels will become hardened. Perform injections every three to four weeks. Four to six sessions may be needed to complete the course of therapy. On ultrasound, these vessels will not be able to compress and there is no filling on color flow Doppler.
It is important to note that once an individual has venous insufficiency, it does not go away and may in fact affect other veins. Other veins may become insufficient due to increased load and hypertension, and new vessels can develop. This process is called neovascularization. It is necessary to perform maintenance and follow-up care to ensure a new ulceration does not develop. Performing procedures to improve and control the chronic venous insufficiency should be the focus of venous ulcer healing. Depending on the size and healing potential of the patient, the wound healing time is significantly shorter. This positively affects all aspects of patient care including increased patient adherence, decreased risk of infection, decreased healthcare costs and more efficient medical care. Dr. Schoenhaus is in private practice in Boca Raton, Fla. Editor’s note: For related articles, see “Managing Ulcers In The Lower Extremity” in the May 2004 issue of Podiatry Today (www.podiatrytoday.com.article/2590 ) or “Current Options In Treating Chronic Venous Ulcers” in the September 2004 issue (www.podiatrytoday.com/article/2956 ). For other related articles, visit the archives at www.podiatrytoday.com .