In recent years several minimally invasive catheter techniques have been developed as substitutes for the classic operation. The affected vein is punctured with a needle as for blood samples and, by means of this access, a radio frequency or laser probe is placed in the vein to be treated – in most cases at the calf. Under local anesthesia, the vessel may then be closed from within through the probe by the effects of heat produced. Contrary to the (foam) sclerotherapy, this result can always be reached by only one treatment. In case there are branch varicosities in addition to the main vein, these can be treated by other techniques in the same intervention or at a later point of time. A complete regression of the diseased branches by the catheter treatment of the main vein alone can rarely be expected. Until the first check-up after one week the patients wear a stocking or bandage and should avoid strenuous physical activity.