Laser treatment of varicose veins
Medical care in the 21st century is evolving into a minimally invasive specialty. Procedures once performed under general anesthesia where patients' bodies were surgically opened to allow REMOVAL of organ systems are
being replaced by techniques that allow the TREATMENT of damaged organ systems to occur with the patient awake. This evolution has entered the field of Phlebology.Endovenous laser treatment (EVLTTM
) allows delivery of laser energy directly into the blood vessel lumen in order to produce endothelial and vein wall damage with subsequent fibrosis, as illustrated in Figure 1. It is presumed that destruction of
the GSV with laser is a function of thermal destruction. The presumed target is intravascular red blood cell absorption of laser energy. However, thermal damage with resorbtion of the GSV has also been seen in veins
emptied of blood. Therefore, direct thermal effects on the vein wall probably occurs. The extent of tissue thermal injury is strongly dependent on the amount and duration of heat exposure.
Histologic examination of the treated and excised veins demonstrates thermal damage along the entire treated vein
with evidence of perforations at the point of laser application. This is described as "explosive-like" photo-disruption of the vein wall. This produces a homogeneous thrombotic occlusion of the vessel.
Another possibility for the mechanism of action of EVLT is similar to RF closure, collagen contraction. Collagen has been noted to contract at about 500C, while necrosis occurs
between 700C and 1000C. Whether collagen contraction, thermal damage or a combination of these effects is responsible for destruction and resorption of the GSV is unknown.
Initial reports have shown this technique to have excellent short-term efficacy in the treatment of the incompetent GSV, with 96% or greater occlusion at 9 months with a less than 1% incidence of transient paresthsia.
1,2 Although most patients experience some degree of post-operative ecchymosis and discomfort, no other major or minor complications have been reported. 1
The lack of significant heating of perivenous tissues probably explains the low complication rate encountered and argues well for the continued lack of significant complications.
Our patients treated with EVLT have shown an increase in post-treatment purpura and tenderness.3 Most of our patients do not return to complete functional normality for 2-3 days as
opposed to the 1 day "down-time" with RF Closure of the GSV. Since the anesthetic and access techniques for the 2 procedures are identical, we believe that non-specific
perivascular thermal damage is the probable cause for this increased tenderness. We await longer-term results from patients already treated with EVLTTM and additional refinement
and evaluation of this promising new technique, which may offer a good alternative to ligation and stripping for those patients wishing to avoid surgery. Refs. 1. Min RJ, Zimmet SE, Isaacs MN, Forrestal MD. Endovenous laser treatment of the incompetent greater saphenous vein. J Vasc Interv Radiol
2001; 12:1167-1171. 2. Navarro L, Min RJ, Bone C. Endovenous laser: a new minimally invasive method of treatment for varicose veins- preliminary observations using an 810-nm diode laser. Dermatol Surg 2001;
27:117-122. 3. Goldman MP: Endovenous Laser Treatment of the Greater Saphenous Vein: Continuous vs. Pulsed Treatment. Dermatol Surg 2002 (in Press). |
