A CVC is a flexible, long, plastic, y-shaped tube that is threaded through your skin into a central vein in your neck (jugular vein), chest or groin (femoral vein). A CVC is not usually intended to be a permanent type of access because of the risk of infection. If you need immediate or emergency dialysis or cannot receive and don’t have an AV fistula or graft, you will require a CVC. You should understand what are the potential advantages and disadvantages are of a CVC:

Advantages

• Quick to place and remove
• May be used immediately for dialysis
• CVC placement can be performed as a day surgery procedure under local anaesthetic with some sedation if required

Disadvantages

• May damage central veins in the medium to long term 
• Bathing and swimming not recommended
• Complications can include infection at the site of insertion but also affect the systemic circulation and catheter blockage

There are two types of CVCs, tunnelled and non-tunnelled:

• Non-tunnelled catheter access is for short-term access (up to about 2 weeks) and the catheter emerges directly from the skin at the site of entry into the vein.
• Tunnelled catheter (also known as Permanent Catheters) access is usually more long term, involves a longer catheter, which is tunnelled under the skin from the point of insertion in the vein to an exit site some distance away. It is usually placed in the internal jugular vein in the neck, and the exit site is generally on the chest wall. The tunnel acts as a barrier to invading bacteria.  Although called a Perm Cath, such tunnelled catheters are designed for short- to medium-term access because of the risk of infection. We do not recommend placing a Perm Cath for more than 6-12 months. However this will allow for us to form a more definitive type of access such as a AVF, AVG or PD catheter.

• An AVF is considered currently the gold standard for vascular access for haemodialysis. This is basically a surgical connection between an artery and a vein, more commonly performed in the forearm/arm region or if those sites are exhausted, in the thigh area. It is the preferred access creation because it can usually last for a longer time than an artificial graft or catheter tube and is less susceptible to infection because no foreign material is used as the conduit. It is created by stitching an artery and a vein together, usually in the non-dominant arm in either the wrist, forearm or elbow areas.
• An AVF creation results in an increased blood flow rate through the vein, which helps enlarge and strengthen the vein. An AV fistula allows a higher rate of blood to flow back and forth from your vein to a dialysis machine for efficient blood cleaning.
• The AVF may take up to 2-3 months to mature and become functional, especially if the vein and artery are small to start with. Generally, an AVF has fewer complications than AVG especially in Singapore. An AVF is usually created as a day surgery procedure under local anaesthesia.

Advantages

• Can function for years if well taken of
• Not as likely as a catheter to become infected
• Not as likely to clot than an AVG

Disadvantages

• May require another temporary type of access during the healing and maturation phase such as a CVC
• Maturation may be delayed, or it may fail to mature
• Needles are required to access the AV fistula for haemodialysis usually 2-3 times per week
• The AVF may need servicing from time to time, because the needling process can cause trauma and scarring to the vein with continued use causing narrowing and potential blockage.

The third type of access, called an AV graft, functions similarly to an AV fistula. If you have blocked or damaged veins, or veins that are too small for an AVF creation, you may be a candidate for an AV graft. AV graft placement is also a surgical procedure, but instead of connecting the artery directly to the vein, one end of a small hollow, synthetic tube will be connected to your vein, and the other end will be connected to your artery like a bridge and the needling process will be performed via the synthetic tubing.

Advantages

• Can be used more quickly than an AVF between 3 days to 2 weeks depending on the type of synthetic tube placed and patient’s needs.
• Easy to implant
• Placement can be performed as day surgery but may need more than local anaesthetic.

Disadvantages

• Doesn’t last as long as an AV fistula
• Needles still required to access the graft
• Prone to clotting and higher risk of infection compared to AVF

A PD catheter is used for peritoneal dialysis, which uses the lining of your tummy and a dialysate solution to clean your blood. This type of dialysis can be a desirable method for people who are always on the go. With a PD catheter, dialysis can be performed at home and takes less time to accomplish and can be performed overnight, whilst patient is asleep. It is also more gentle on the heart and patients with end stage kidney disease usually do have some heart problems as the systems are linked. However it does require that your abdomen has not had major surgery as the scarring can be prohibitive for efficient blood cleaning. If you are unable to care for yourself, have an abdominal hernia or inflammatory bowel disease, recurring diverticulitis PD catheter may not be an option for you.

Advantages

• PD Catheter Placement is usually performed as a day surgery procedure
• No need to use needles
• Dialysis can be performed at home
• No need for a temporary CVC usually 

Disadvantages

• Bathing and swimming not recommended
• Higher risk of infection, tube twisting and migration
• Cannot be used for ever (maximum average use 5-7 years) as the tummy wall lining becomes scarred and prevents efficient blood cleaning.

Getting to the point where you have to seriously consider dialysis can be a scary time. But being prepared and understanding all types of dialysis access means you can feel confident in the choice you and your specialist make. Be sure to carefully consider each of the various types of dialysis access and we would be very happy to discuss which option will offer you the best quality of life.