Commentary: An investigation into the influence of various gases and concentrations of sclerosants on foam stability.

BACKGROUND Foam sclerotherapy is an increasingly popular modality in varicose vein treatment. Our previous work showed that the half-life of room air foam varied according to the percentage and type of sclerosant solution. MATERIALS AND METHODS A plastic connector was used to create foam made from a combination of 0.25%, 0.50%, and 1% sodium tetradecyl sulfate (STS) and room air, carbon dioxide (CO(2)), oxygen (O(2)), or a mixture of CO(2) and O(2). To measure foam stability, the foam half-life was defined as the time it took for half the original volume of sclerosing solution to settle. RESULTS Half-life varied according to sclerosant concentration when room air, O(2), or a mixture of CO(2) and O(2) was used for foam creation but not when CO(2) was used. Room air foam is more than 3 times as stable as CO(2) foam and 1.5 times as stable as a mixture of CO(2) and O(2). CONCLUSIONS CO(2) foam half-life did not vary according to sclerosant solution concentration, though room air, O(2) , and CO(2)/O(2) did. The half-life of room air foam is more than 3 times as long as that of CO(2) and 1.5 times as long as that of a mixture of CO(2) and O(2). Foam half-life for room air and O(2) are similar at low concentrations of STS but differ at higher concentrations.