let's start with the question most people have what is a central venous access device or C VAD ac VAD is a thin soft flexible tube that is inserted into a large vein leading to the heart the tube also called a catheter exits near the surface of the skin the C VAD can contain a single channel or multiple channels these channels are called lumens sieve ads are used for long-term delivery of medication nutrition and fluids blood can also be drawn from the line for testing since the central line goes into your vein and is placed near your heart it's helpful to have an understanding about your veins and how your circulation works your circulatory system is made up of your heart and blood vessels the heart pumps blood through the blood vessels around your body the blood vessels are tubes and are called arteries and veins the blood vessels that carry blood away from the heart are called arteries the arteries deliver oxygen and nutrients to all the cells the blood vessels that carry blood back to the heart are called veins AC VAD is a longer catheter with a tip that ends in a larger vein near the heart usually the superior vena cava AC VAD can stay in months to years it is threaded under the skin and the delivery tip is in a central vein far from the skin insertion site which helps decrease the risk of infection and protects it from minor bumps and tugs since the vein is large medicine and fluids given through a central line typically do not irritate the vein lining