Factors affecting the longevity and quality of detergent sclerosant foams

ObjectivesDetergent sclerosant foam quality varies between syringe brands and devices. This study examined the foam duration and quality of using multiple syringe brands, connectors and foam making devices.MethodsA range of widely available syringes, connectors and foam making devices were tested with the sclerosants sodium tetradecyl sulfate (STS) and polidocanol (POL). 1% and 3% solutions were tested because these are licensed for use as foam. The manufactured foam containing syringe was inverted and the breakdown of foam recorded with a digital video camera. The time taken for the liquid to reform according to the syringe graduations was recorded. Additionally, qualitative observations were recorded.ResultsSignificant differences between syringe brands were observed in the foam longevity for 1% STS, 3% STS and 1% POL but not for 3% POL. There were no significant differences between connectors or foam making devices. The qualitative observations revealed large bubbles and rapidly degenerating foam in some syringes even if the liquid reformation was slower.ConclusionsSyringe brand affects the longevity and quality of sclerosant foam especially with STS and 1% POL but not with 3% POL. It is inferred that the cause of the differences is due to the syringe siliconisation and the mode of sterilisation. Liquid reformation should not be the only criteria for assessment; a qualitative observation of the foam in the syringe should always be made.