И последнее - Deep vein thrombosis (DVT) is an important complication that occurs in less than 1% after endovenous procedures. Some controversy exists concerning prophylaxis with low-molecu- lar weight heparin (LMWH). Although the reported incidence of DVT is very low, physicians feel uncomfortable with this thrombotic risk. Therefore some authors have suggested the routine use of LMWH after EVTA, while others suggest administering LMWH only in high-risk patients.11-12 At our centre we have chosen not to administer LMWH routinely, but only in high-risk patients. However, the definition of a high-risk patient is not always well defined.The diagnosis of DVT after EVTA is also controversial somehow and the clinical importance of what has been called ‘endothermal heat induced thrombosis’ (EHIT) is still unclear. Duplex ul- trasound findings will be different at different time intervals after EVTA. Thrombus extension into the deep venous system, sometimes even a floating thrombus, is more often seen the first few days after EVTA procedures. After 1 or 2 weeks, such thrombus extension is dissolved and hence not visible any longer on ultrasound examination. Physicians who investigate their patients routinely shortly after the endovenous procedure report more often DVT and will more often treat these patients with LMWH. This problem of definition (which may result in bias) might have occurred in one study which reported an exceptionally high number of DVT (5.6%). In this study DVT was defined as “a tail of thrombus protruding into the popliteal vein” at the 1-week follow-up duplex examination.13 In fact, such thrombus usually disap- pears quickly, and is therefore different from a true DVT.