title: An investigation into the influence of various gases and concentrations of sclerosants on foam stability.
abstract: 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.
  
  
  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.
authors.affiliation: Dermatology Cosmetic Laser Associates of La Jolla, La Jolla, California, USA.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Peterson
authors.forename: Mitchel P
authors.initials: MP
authors.lastname: Goldman
mesh_terms: D002245:Carbon Dioxide / Q000008:administration & dosage / Q000737:chemistry*; D004304:Dosage Forms; D004355:Drug Stability; D006207:Half-Life; D006801:Humans; D010100:Oxygen / Q000008:administration & dosage / Q000737:chemistry*; D012597:Sclerosing Solutions / Q000008:administration & dosage / Q000737:chemistry*; D015911:Sclerotherapy / Q000295:instrumentation*; D013594:Syringes; D014648:Varicose Veins / Q000628:therapy*
chemical_list: D004304:Dosage Forms; D012597:Sclerosing Solutions; D002245:Carbon Dioxide; D010100:Oxygen