Laser-tissue interaction in endovenous laser treatment

The authors present the results of recorded changes in the endothelium in rabbit's veins following photocoagulation by laser diode. This study concentrates mainly on the detailed description of individual changes in the rabbit's venous system in the area of pelvis following laser therapy. The aim of our experiments was to reach the obliteration of rabbits' lateral saphenous vein using 980 nm laser diode with 200 micron fibre. The intensity of discharge was 3, 5, 6 and 7 watts. We examined the relationship between changes and the amount of joules that affect the endothelium of the rabbit's veins. The operation was conducted under general anaesthesia. All animals survived treatment and were returned to breeders. Within the time span of one, three, six and eight weeks the laser treated veins were removed. They were fixed in formaldehyde and sent for microscopic examination. We were interested in how long it will take for fibrous changes to occur in the endothelium of the vein and thus also the subsequent occlusion of the vein depending on the amount of joules applied per one centimetre of the vein (Tab. 1, Fig. 4, Ref 6).