The device containing sclerosant liquid for use in the treatment of blood vessles comprises an aerosol valve housing mounted on a canister having an expandable inner container in which the sclerosant fluid is contained, wherein the expandable inner container is affixed to the outer opening of the canister or to the aerosol valve housing, whereby the introduction of pressurised gas through the aerosol valve causes the expandable inner container to inflate to accommodate the pressurised gas.
