Comparison of the Proximal Approach and Distal Approach of Axillary Vein Catheterization Under Ultrasound Guidance in Cardiac Surgical Patients With Risk of Bleeding: a Prospective Randomized Controlled Trial

For patients after cardiac surgery, antiplatelet drugs or anticoagulants are usually used for preventing thrombosis. Use of those drugs is associated with increased risk of bleeding. Any invasive procedures may put those patients at additional risk of bleeding. Ultrasound (US) has become widely accepted to guide safe and accurate central venous catheterization.The axillary vein in the infraclavicular area is an alternative choice for subclavian vein. Ultrasound images of the infraclavicular axillary vein differ according to its position. Proximal infraclavicular axillary vein is a direct continuation of the subclavian vein. The associated anatomy is simple and the vein is straight and thick in longitudinal axis view, which are in favor of successful puncture. Meanwhile, distal axillary vein also has anatomical advantages for safe and successful cannulations. Distal axillary vein lies further away from the artery and chest wall, and the overlap between distal axillary vein and artery gets greater on moving laterally. It is still unknow that one of the puncture approaches is superior to the other. Until now, there are no studies comparing two puncture approaches in high bleeding risk patients. The aim of the study is to compare the success rate of first puncture and safety of US-guided proximal and distal axillary venous catheterization in cardiac surgery patients with risk of bleeding.