US Patent 7311697 Central venous catheter

A central venous catheter comprises a catheter body having a plurality of lumens extending longitudinally therein. At least one of the lumens extends longitudinally through the catheter body from its proximal end to an exit port at its distal end, and at least one other lumen extends longitudinally through the catheter body to a closed distal portion of the catheter body. The catheter body further includes a sideport positioned to establish communication between the closed-end lumen and an area exterior to the catheter body. The catheter body further includes a flexible member, such as a coiled spring, in the closed-end lumen in a space between the sideport and the closed end.