 Most symptomatic cases are seen with placement of femoral vein catheters (3.4%) or peripherally inserted central catheters (3%).Anti-clotting drugs such as heparin and fondaparinux have been shown to decrease the incidence of blood clots, specifically deep vein thrombosis, in a person with cancer with central lines.Additionally, studies suggest that short term use of CVCs in the subclavian vein is less likely to be associated with blood clots than CVCs placed in the femoral vein in non-cancer patients.