A Review of Sclerosing Foam Stability in the Treatment of Varicose Veins.

Background: Varicose veins are common clinical entities. Foam sclerotherapy is a minimally invasive and simple procedure; however, the side effects, efficacy, and stability of sclerosing foam are not ideal.
Objective: To summarize the current studies on sclerosing foam stability and promote foam sclerotherapy development.
Materials and Methods: We reviewed the literature before June 2018 and included only representatives studies on sclerosing foam stability. We summarized the foam half-life time (FHT) of polidocanol (POL) under 17 preparation conditions and the FHT of sodium tetradecyl sulfate under 21 preparation conditions. The preparation conditions included various combinations of temperature, liquid-gas ratio, preparation method, etc. RESULTS: The FHT of POL varied between 40 and 4,000 seconds under different conditions. The FHT of sodium tetradecyl sulfate varied from 25.7 to 390 seconds. The higher the drug concentration, the lower the temperature required to increase foam stability. The addition of surfactant greatly increased foam stability. For different gas compositions, the FHT sequence was as follows: CO2 < CO2 + O2 < O2 < air.
Conclusion: Foam stability can be improved by changing the preparation conditions; therefore, the role of surfactants and predictive methods for FHT are worth investigating further.