The development of minimally invasive methods to heat, denature, and shrink varicose veins has been a major achievement in the field of phlebology and medicine. Minimally invasive endovenous occlusion techniques using radiofrequency (RF) or laser are now the standard of care in the United States. When saphenous venous system reflux is present, it must be addressed prior to the treatment of visible associated varicosities, reticular veins or telangiectasias. Without elimination of reflux, the patient will be doomed to recurrence of the varicosities and smaller vessels below the level of saphenous vein reflux. Previously, the only treatment option for these patients with varicose veins from saphenous insufficiency was surgical ligation and stripping of the vessels under general anesthesia. This procedure resulted in significant postoperative down time with surgical scars, swelling, bruising, and pain. The expense of a hospital stay and missed work, along with an unacceptable rate of recurrence, has greatly decreased the popularity of this procedure.
RF ablation started the minimally invasive varicose vein trend with its approval in March 1999 by the US FDA as the VNUS Closure™ procedure, now known as the Venefit™ procedure. Subsequently, endovenous ablation techniques utilizing lasers were filed as US FDA 510(k) applications as substantially equivalent procedures to RF ablation. The first laser FDA cleared by substantial equivalence to RF was the 810 nm diode laser, which was cleared for marketing in 2000.
The advances in endovenous ablation have revolutionized in-office varicose vein treatment for physicians and patients. RF energy, like a laser with a water absorption predominant wavelength, heats and contracts the collagen within the vein wall causing contraction of the varicose vein. Endovenous laser treatment of varicose veins can be divided into two categories: hemoglobin absorption predominant and water absorption predominant. The water absorption predominant wavelengths are primarily above 1100 nm, in which hemoglobin is no longer a chromophore (Fig. 45-1).
Absorption curves of light through infrared wavelengths. There is virtually no absorption by hemoglobin beyond 1100 nm. Water is the target of 1320 nm.
VENEFIT™ PROCEDURE (COVIDIEN, SAN JOSE, CA)
Targeted Endovenous Therapy
RF energy is delivered through a specially designed endovenous electrode to accomplish controlled resistive heating of the vessel wall. This causes vein shrinkage or occlusion by contraction of venous wall collagen to eliminate saphenous venous reflux. Although the concept of endovenous elimination of reflux is not new, previous approaches have relied on electrocoagulation of blood. This resulted in thrombus occluding the venous structures, with the potential for recanalization of thrombus being very high. The concept of application of RF directly to tissue, rather than blood, has been effectively applied for ablation of abnormal conduction pathways for arrhythmias.1 This concept was conceived and adapted for the treatment of varicose veins as well. The potential ...