In routine practice, a 0.5% or 1% concentration of foam sclerosant is preferred for vessels less than 5 mm in diameter, while 2% and 3% concentrations are used for vessels larger than 5 mm in diameter. In one ex-vivo study they were unable to demonstrate any statistically significant results among different foam concentrations on 5-10 mm diameter vessels in terms of pathological damage. However, due to the near significant difference between the outcomes of 0.5% and 1% foam sclerosants, the use of 1% foam sclerosant instead of 0.5% may be preferable. Again, 1% foam sclerosant may be preferred to 2% or 3% in larger vessels, as it exerts more severe damage on the vein wall. Further studies are necessary to validate these findings. We have been using the 1% sclerosant for vessels between 5 -10 mm diameters for the past few years without significant recanalizaiton or residual varicosities. Axial veins seem to be more resistant to obliteration by the sclerotherapy compared to the tributaries in clinical practice.
