Central venous catheters improve the tolerability and feasibility of patient care in the hospital setting by allowing the administration of hyper-osmotic, vesicant and venotoxic fluids. Despite these advantages, the long-term presence of central venous catheters is associated with thrombotic and infectious risks , including catheter-related bacteremia, which can be complicated by septic thrombophlebitis and endocarditis that can lead to death. Septic thrombophlebitis is a complication of venous catheter infections, which increases the morbidity. It is defined by the presence of a thrombosis in the vein where the venous catheter is located, associated with a bacteremia. A distinction is made between superficial and deep thrombophlebitis. The frequency of septic thrombophlebitis of venous catheters is variable and poorly described in the literature. When the diagnosis of septic thrombophlebitis is made, it is recommended to extend the duration of antibiotic therapy, to remove the infected catheter and to prescribe anticoagulant treatment. However, there is no recommendation on the duration of anticoagulation for septic thrombophlebitis, whether it is deep or superficial. Investigator proposes a prospective and descriptive interventional study to describe the ultrasound evolution of thrombus in patients with septic thrombophlebitis on central venous catheter and midline.