clacs clacs clacs (cryo-laser and cryo-sclerotherapy) is a treatment for leg vein lesions by combining transdermal laser effect and injection sclerotherapy, all under skin cooling (cryo - cold air blown onto the skin at -20c).state of the art on cryo-laser cryo-sclerotherapy in lower limb venous aesthetic treatment the laser causes a selective photothermolysis damaging the vein wall. the vein's lumen gets smaller. on a second procedure, sclerosing agent is injected where the vein is still open. this combination allows to treat veins that could be treated by phlebotomy or foam sclerotherapy - more invasive options. to improve results, clacs can be guided by augmented reality (near-infrared vein finder). clacs was created by dr. roberto kasuo miyake, in 2002, to adhere to patients' requests for treatment that did not require hospitalizations.