Insight Into VNUS Closure Procedure and EVLT – Two Revolutionary Vein Treatment Modalities
Two minimally invasive varicose vein treatment modalities; more specifically, the VNUS closure procedure, also known as VENEFIT, and EVLT (enovenous later treatment), both introduced at around the early years of this decade, gained such a strong foothold in the arsenal of physicians treating varicose veins, that the role of scalpel became insignificant, varicose vein treatment moved from the hospital to the office setting, and a diverse group of physicians, ranging from cardiologists to radiologists, entered into the field of varicose vein treatment. As a consequence of this revolution in the management of vein disease, the American College of Phlebology was established, having as a goal the provision of knowledge and skills required for the use of new vein treatment technologies. In the year 2005, the American Medical Association, AMA, recognized phlebology as a separate self-designated specialty, the same as dermatology, vascular surgery, or any other recognized specialty. At present, Dr. John Mauriello, an anesthesiologist by his primary training, is the president-elect of the American College of Phlebology.
The differences between the VNUS closure procedure and EVLT are subtle. Both are endovenous in nature; meaning, varicose veins are accessed and treated from inside the veins. Whereas, the former uses a disposable catheter equipped with a radiofrequency (RF) generating electrode, the latter uses a reusable laser producing fiber. RF closure was first introduced in Europe in 1998 and was cleared by the US Food and Drug Administration (FDA) in March 1999. Endovenous laser vein treatment was first described in 1999 and FDA approved in the year 2002. It should be noted that EVLT is a trademarked term and several other acronyms, such as EVLA and CTEV, are trademarked with claims that their laser fibers and wavelength result in less pain than others. Although many different radiofrequency ablation catheters are available for a variety of medical applications, the ClosureFAST catheter and ClosureRFS Stylet, manufactured by VNUS Medical Technologies, currently are the only commercially available and FDA approved systems designed for venous ablation.
Despite the occasional use of the VNUS closure procedure and EVLT for cosmetic purposes, their main use is for varicose vein treatment, or the underlying cause, venous reflux (pooling of blood in the veins of lower extremities due to faulty vein valves) and alleviation of symptoms associated with enlarged nonfunctional saphenous and perforator veins. Saphenous veins are the largest and longest superficial veins; whereas perforator veins are short connecting veins located along the entire length of the legs. When diseased, these veins allow reverse flow and channel blood directly from the deep veins into the superficial ones. Leg symptoms, often not related to vein size or abundance, can include: aching pain, swelling, skin irritation or sores (ulcers), discoloration, and inflammation (phlebitis).
Varicose vein treatment, with either EVLT or VNUS closure, takes less than an hour. A treatment session starts with Ultrasound imaging to identify the diseased sections of the veins. This is followed by the injection of tumescent anesthesia all along the diseased vein and the insertion of a tiny catheter into a vein, usually near the knee. Using Ultrasound imaging, a laser fiber or a radiofrequency electrode is then inserted through an intravenous access port (similar to but larger than an IV catheter) and is guided up the thigh and positioned precisely at the very source of reverse flow. In the case of EVLT, the laser fiber generates a laser beam, which heats and boils the blood in the vessel causing it to shut. In the VNUS closure procedure, the radiofrequency generated by the electrode selectively heats and contracts the collagen in the vein wall and results in a fibrotic seal. A session terminates with the application of bandages to the treated leg, followed by compression hosiery. Compression is of vital importance after any venous procedure because its use prevents stagnation of blood in the treated leg, prevents bleeding from puncture sites, promotes faster healing of the treated veins, and reduces post-operative bruising, tenderness and clot formation. Injection of local anesthetic around the abnormal vein is the most bothersome part of the procedure because it usually requires multiple injections along the vein. Actual closure of the vein with laser or radiofrequency is usually completely painless. Of course, a follow up ultrasound examination is essential in order to assess the treated vein and to check for adverse outcomes. Although not common, a small number of EVLT patients require narcotic medications during the few days following the treatment. It is hoped that some of the newer LASER wavelengths, energy settings, and newer laser fibers will improve the technology and reduce the pain caused by the procedure.
As to the limitations of the endovenous procedures, despite some scattered reports of skin burns, the procedures can be considered quite safe. In fact, both procedures can be performed on very thin legs or very superficial veins without causing injury to neighboring tissue or the skin. The large volumes (500 cc) of dilute Lidocaine (0.1%) tumescent anesthesia, injected along the entire saphenous compartment prior to the application of radiofrequency, has the double role of compressing the vessel against the catheter (for better outcome) and providing a heat sink that absorbs the heat created by the device. According to a renowned Los Angeles phlebologist, Dr. R. Dishakjian, liberal use of tumescent anesthesia pushes the saphenous vein at least 1 cm away from the skin and eliminates any potential injury and burns to surrounding soft tissue structures including nerves, other veins, arteries and skin. It should perhaps be mentioned that the application of tumescent anesthesia for endovenous vein treatment was first patented in the United States by VNUS Medical Technologies, who have filed several patent infringement lawsuits against companies selling endovenous laser vein ablation systems. Not all litigations are settled yet.
For situations where the saphenous veins are very large, the Los Angeles phlebologist says: “despite the fact that the endovenous catheters are thin, it is possible to treat veins as large as 16 mm, because the epinephrine added into the tumescent anesthesia provides improved constriction of the vein around the heat-generating tip of the catheter, while also prolonging the analgesic effect of Lidocaine for up to 6 to 8 hours post-procedure.” The doctor adds, “even significantly tortuous (curved) veins can be treated with the endovenous technique. In such cases where the catheter tip cannot be advanced through the entire length of the vein, a second catheter entry point may be used to bypass a curved part. The existence of blood clots in the veins is the only absolute contraindication to both EVLT and the VNUS closure and require surgical intervention.”
Unfortunately, endovenous techniques do not often solve the problem of branch varicosities and spider veins. When left untreated, only 10% to 20% of patients will have regression of these branch varicosities to the point where no further intervention is necessary. Residual varicose veins following the procedure can be treated with a variety of techniques. Treatment options may include phlebectomy simultaneously with vein ablation or delayed treatment following the observation for spontaneous regression. If delayed treatment is selected and necessary, either phlebectomy, sclerotherapy, or foam sclerotberapy may be chosen depending on the physician’s preference. Phlebectomy involves the surgical excision of a vein or part of a vein; whereas, sclerotherapy and foam sclerotherapy use a needle to inject a medicine either in the form of a fluid or foam directly into the diseased vessels.
As with other varicose vein treatment techniques, continued occlusion of the saphenous vein with either the VNUS closure procedure or EVLT does not eliminate the possibility of developing recurrent varicosities. Recurrent varicose veins from untreated vein segments or new reflux can and will occur in some patients. This, however, does not represent a failure of endovenous ablation. Varicose vein treatment with endovenous ablation techniques have proven to be as effective as conventional surgical management and have led to increased patient satisfaction.