The risk of deep venous thrombosis after radical breast surgery is known. The objective of this study is to explore hypercoagulability after radical breast cancer surgery by studying several factors for haemostasis before, during and after surgery. Ultrasound Doppler examination is realised between 24 and 72 hours post-operatively. Hypercoagulability is defined by a significant increasing level of thrombin-antithrombin, D-dimer and the endogen thrombin potential.