Devices: Central lines and ports

Medications and fluids that need to be given into a vein (intravenously) can be given through a cannula, which is placed in a small vein on the hand or arm. 

For many children this is painful and unpleasant and restricts their activities. For this reason, the oncologist may recommend that a central line or port is inserted. 

What is a central line?

A central line, also called a central venous line or CVL, is a long, thin, flexible, plastic tube, which is inserted into a vein usually near the collarbone. A CVL can be used to give treatment such as chemotherapy, antibiotics, blood products, nutrition, fluids and other medicines. It can also be used to take samples of blood for testing.

Why the central line?

  • avoid frequent needles
  • fluids or medicines that are not compatible can be given at the same time due to the central line having multiple openings
  • a child can go home from hospital with a central line in place, and it can be left in for months or years if needed. 

Types of central lines

  • CVL: external line where tube sits outside of the chest 
  • Portacath, Infusaport: internal line that stays under the skin. 

With both types of lines, infection can be a problem (see 'Care of the central line' below). 

How the central line is put in

The procedure is completed under a general anaesthetic. The surgeon makes a small cut into a vein near the collarbone and feeds the tube down until the tip is in one of the large veins near the heart. 
The other end of the tube is then placed under the skin and comes out on the front of the chest. 
A removable bung is attached to the end of the line, which allows samples of blood to be taken or medicines to be injected. It can also be used to give blood or platelet transfusions. 

Implantable port (portacath) 

An implantable port (portacath) is a thin, soft silicone rubber tube that is put into a vein in the chest.  
The tube has an opening (port) just under the skin, which allows medicines to be given into the vein, or blood to be taken from the vein.  
The port is a disc about 2.5cm–4cm in diameter. It is inserted in the same way as a central line except the catheter does not exit the chest wall. It will show as a small bump underneath the skin below the collarbone. Nothing is visible on the outside of the body. 

Using the port
The port is used in the same way as the central line, but there is usually only one opening. In order to use a port, a needle is put through the skin . The needle is then attached to tubing to give the medicine or fluid. Once all the medicine has been given, the needle is removed. 

Bathing and showers 
Ports are less likely to develop infections or breakages than central lines, and swimming is permitted with a port. Showering or bathing as normal is encouraged. There is no dressing required for a port when it is not in use. 


The Insuflon is a small plastic device inserted under the skin, which can remain in place for up to five days.

The Insuflon is often used in children who need treatment with G-CSF, as it means this medicine can be given without repeated injections, reducing pain and psychological trauma. 

The parent, patient or a nurse can administer the G-CSF. With Insuflon in place, your child can continue their normal activities, including bathing and swimming.

CVL versus Portacath

Your child’s treating team will discuss with you the advantages and disadvantages internal and external central lines and suggest the more suitable option for your child.

For more intense treatment, especially if a bone marrow transplant is anticipated, a central line will be recommended.

Care of the central line

Blockage prevention 

When the central line is not being used, there is a small risk that it may become blocked. To prevent this, a small amount of saline with a medication called heparin (which stops blood from clotting) is ‘flushed’ through the line using a syringe.

This must be done once a week. The exit site also needs to be cleaned and its dressing replaced once a week to reduce the risk of infection.

CVL complications include: 

  • Infection

 You should contact the hospital if:the exit site becomes red, swollen, or painful and/or if your child has a temperature. 

  • Clots or blockage

It is possible for a blood clot (thrombosis) to form in the vein around the tip of the line. 

  • Dislodgement

The central line can accidentally fall out or be pulled out. 

  • A cut or break in the line

If the line does get a cut or split, try to clamp it between the split and the exit site (where it comes out of the body) and contact the hospital. Never use a scissors near the line or dressing. 

Always wash your hands before touching the line or dressing. If you see any redness, swelling, pus, shaking or chills after 'flushing' or your child complains of pain, call your doctor right away. 

Last updated Wednesday 26th June 2024