Laser beams interaction with polidocanol foam: molecular background.

The goal of this study was to investigate the laser light scattering involved in the laser irradiation process of polidocanol foam samples. Clinical experimental results proved that exposure of tissues impregnated with foaming polidocanol to laser radiation emitted at 1064 nm improved the efficacy of the treatment. Previous absorption studies on Aethoxysclerol 2% solution before and after exposure to Nd:YAG (1064 nm) laser beam have not shown important spectral modifications of it. To achieve the purpose of this work, we produced polidocanol foam using the Tessari method. The batch was passed between the two syringes ~40 times. The resulting foam was stable for 5-6 min. A 10 mm optical cell containing the foam sample was introduced into a home-made Raman spectroscopy system, in which the laser radiation used to excite the Raman emission was the second harmonic (532 nm) of a pulsed Nd:YAG laser beam. The detection was made by a high resolution spectrograph and ICCD camera. The obtained Raman spectra were more intense in foam form than in simple solution. The laser light elastic scattering produced a larger optical path of the beam in the sample, and consequently, a larger absorption of it by the foam components that enhance the laser Raman scattering. The effect of the laser light may be expanded if the polidocanol is used as foam, because then the light scattering in the tissue becomes more important and the beam absorption becomes larger.