[Role of optical properties of the venous wall for endovenous laser obliteration].

Presented herein are the results of studying the optical density of water, blood, and venous-wall tissue for various-wavelength laser radiation, with determining the peaks of absorption of radiation by the above-mentioned media. The absorption peaks in water and blood correspond to wavelengths of 1,450 and 1,935 nm, respectively. Peaks of absorption in the venous-wall tissue are within the intervals equaling 650-950 nm, 1,445-1,455 nm, and more than 1,900 nm. Also determined was the optical density of the veins for the most frequently used in clinical practice wavelengths, i. e. 1,030 and 1,470 nm, with the calculation of the portion of the absorbed energy depending on thickness of the layer of the absorbing substance. Based on the obtained findings, a conclusion was drawn on better utilization of the energy of one-and-a-half-micron range laser radiation and on its preferable use for endovenous laser obliteration (EVLO).

[Venous wall perforations as the leading reason of a painful syndrome after endovenous laser ablation].

This article deals with the problem of venous wall perforation during endovenous laser ablation (EVLA). The sinusoidal type of painful syndrome which arises on 4-7 days after EVLA was shown. A series experiments on the isolated veins using two different lasers were performed. It was demonstrated that vein is squeezed around the fiber during injection of tumescent liquid, which leads to the formation of isolated intimal sinuses. When the blood closed in such sinuses is exposed to laser radiation, it is released of large amounts of gas, which in turn leads to the rupture of the venous wall. Of the earlier idea of perforation of the venous wall with over heated fibre tip has not received confirmation.