A mixer to create foam with microbubbles using physiological gases currently used in sclerotherapeutic treatments of varicose veins has anatomical and compact dimensions and is built with material resistant to sterilization and pressure. The device is mounted on the body around an essentially cylindrical axle comprised of a central valve support, while the top conical body portion is crossed in its center by a flow orienting duct. This axle is coupled at the center of a spinning circular reservoir constituted by the body, containing several housings for the application of solutions with different concentration levels. These parts are locked by a connector at the bottom to the gas duct with a spray nozzle. Each housing has a channel that can be aligned to communicate with the inside of the flow orienting duct of the central axle, responsible for orienting the produced mixture to a top reservoir with a foam-making nozzle.