Biological effect of laser treatment on varicose veins / 国际外科学杂志

ABSTRACT

Objective To evaluate the preliminary mechanisms of endovenous laser treatment (EVLT) for lower extremity varicose vein.Methods Laser energy was endovenously administered to observe its biological effects on greater saphenous vein (GSV) segments with different conditions.Some great saphenous vein that was surgically removed after EVLT was examined by means of histopathology.Cruor status was tested after EVLT.Results Histopathologic examination found the vein wall treated by EVLT showed reddening,carbonization,or even perforation,denudation of the intima,loss of cellular contours,and fibrin deposition.Additionally,some areas showed marked vacuolization of cells or even spongiosis,swelling and waxy homogenization of collagen,focal coagulation necrosis within the intima.In saline-filled veins,EVLT-induced vessel wall injury was confined to the site of direct laser impact.In contrast,blood-filled veins exhibited thermal damage in more remote areas including the vein wall opposite to the laser impact.D-dimer was significantly changed after EVLT.Conclusions EVLT laser induced indirect local heat injury of the inner vein wall by steam bubbles originating from boiling blood is proposed as the pathophysiological mechanism of action of EVLT.Intravascular blood plays a key role for homogeneously distributed thermal damage of the inner vein wall during EVLT.No significant difference could be detected between the two laser wavelengths.Continuous emission mode is better than pulse emission mode.