Vascular catheters have become essential tools for management of hospitalized or chronically ill patients requiring intensive medical treatments such as extracorporeal detoxification procedures. The increased use of such devices has been accompanied by a corresponding increase in complications, such as bloodstream infection and thrombosis. In a retrospective study 332 large bore catheters which were inserted in 182 patients in the inferior or superior vena cava were investigated. The complication rate was in internal jugular vein puncture (N = 231) with 20% low and in the subclavian vein puncture (N = 94) with 60.5% and in the femoral vein puncture (N = 7) with 57.1% very high. The majority of complications were puncture not possible, puncture of the artery, abscess, septicemia, bleeding and thrombosis. To minimize the complication rate the surface of some catheters were treated and the microdomain structured surface inserted. The first results are very encouraging and should help to make large bore catheters safer.