Page "Central venous catheter" Paragraph 13

Specific types of long-term central lines are the Hickman catheters, which require clamps to make sure the valve is closed, and Groshong catheters, which have a valve that opens as fluid is withdrawn or infused and remains closed when not in use.

Hickman lines also have a " cuff " under the skin, to prevent bacterial migration and to cause tissue ingrowth into the device for long term securement.