When your kidneys no longer work, one treatment choice is hemodialysis. Hemodialysis is the process of filtering wastes and removing excess fluid from your body. Your lifeline in hemodialysis is a vascular access—a site from which blood can be safely removed and returned to your body.
There are three types of vascular access and they each have one thing in common. Their job is to make it easier to reach your blood vessels to filter and clean your blood. The three types of vascular access are: fistula, graft, and catheter.
A native arteriovenous fistula (AVF) is created underneath the skin by sewing an artery to a vein, usually in your arm. When your artery is connected to your vein, strong flow from the artery makes the vein larger and stronger. Since your veins are close to your skin’s surface the new access is easy to reach with the two needles needed to perform your hemodialysis treatment.
- Decreased pain and swelling after placement
- Your veins and arteries are part of your body, so a fistula is less prone to infections or blood clots than other types of access, and therefore require fewer interventions.
- Your veins and arteries self heal after each needle stick, so a fistula can last a long time.
- Very good dialysis treatment once fistula matures
About a week after the surgery, patients should start to do exercises that can help their fistula to mature, like squeezing a palm size sponge ball or lifting light weights (1-2 lbs). A fistula usually takes from 8-12 weeks to mature before it will be ready to be used for hemodialysis, so it is best to create one long before dialysis is needed. A fistula can last for years, even decades and research shows that it is the best type of access now available. A fistula is known as the “gold standard” for hemodialysis access. Unfortunately, a fistula cannot be placed in everyone.
A graft uses an artificial blood vessel to bridge your own artery and vein together. This man-made material (ie.gortex), is shaped like a plastic straw and is very soft and flexible. A tunnel is created under the skin, the tube is inserted into the tunnel and then the tube is attached to an artery and a vein. A graft is the second best kind of access. It is often used if your veins have been determined to be very small or weak and would not properly develop into a suitable fistula.
- Easy to use
- Ready to use in about 3-4 weeks (after swelling subsides)
- Can be placed in almost anybody
- Allow good dialysis treatments
- Compared to a fistula a graft is more likely to become infected and/or clotted, because the synthetic material is foreign to your body.
- Grafts develop holes, because the synthetic material does not self-heal like natural tissue after needle punctures.
- Grafts may need to be replaced after 1-2 years because of the many needle holes
Surgery to create a graft is a lot like surgery to create a fistula. After surgery it usually takes between 3-4 weeks before the new graft can be used for dialysis. Grafts have a shorter lifespan than fistulas, usually less than 5 years.
Care of your dialysis fistula/graft
- Wash the skin over the access with soap and water daily, and before dialysis to help prevent infection.
- Do not wear tight sleeves, watches, straps or bracelets on your access arm.
- Do not carry bags or purses across your access arm.
- Never sleep on your arm that has the access or get in a position where your arm might “fall asleep.” Blood circulation can stop and the access will stop working.
- Do not let anyone use your access arm for IV’s, drawing blood, or blood pressures.
- Learn to: Feel for the “Thrill” every morning, during the day, and before you go to sleep to make sure your access is working.
Problems to report:
- Fever, chills or if you feel ill
- You notice the “Thrill” is gone. Call the dialysis clinic or your nephrologist as soon as possible, the sooner this is reported the easier it is to fix and there is a chance of avoiding placement of a dialysis catheter.
The third type of vascular access is a central venous catheter. A catheter is a plastic hollow tube that is surgically placed in the neck (internal jugular), chest (subclavian), or groin (femoral), and connected to a “central” vein. The other end of the tubing is outside the skin and is used for connecting to the dialysis tubing. Most catheters are temporary, used for weeks or months at most. They are mainly for short-term use until a graft or fistula is ready. Of the three types of vascular access, the catheter is the poorest option.
- Because a catheter extends outside the body, it is the most prone to infection and because it is so close to the heart infections are serious.
- Blood flow rates are often poor, so it is hard to obtain adequate toxin removal.
- Catheters are very likely to clot.
- May cause narrowed veins
- Swimming and bathing is not recommended
The biggest benefit of a catheter is that it can be used the same day it is placed for dialysis. So most people who find out they need dialysis right away will have a catheter placed. Rarely will some people need to use catheters for long-term dialysis access. This includes people who don’t have good enough blood vessels, or whose hearts are not strong enough for a fistula or graft.
- It is very important to keep the catheter site clean, dry, and covered with a dressing at all times.
- The site will be cleaned and the dressing changed each time you dialyze.
- The dialysis catheter should only be used for DIALYSIS.
- Wear clothing that will not tug or pull on your catheter, such as button-up shirts.
- Check your catheter daily to ensure that the clamps are closed and the end caps are on securely.
Problems to report:
- The catheter is hurting you
- Blood or fluid drainage at the catheter site
- You have a fever, chills, or feel ill.
- You have tugged or pulled on your catheter by mistake. This needs to be checked closely to ensure the catheter has not migrated out.
- NEVER try to push your catheter back in. This can cause contamination and infection.
- Inform the staff if anyone else (ie. hospital or clinic staff) has used your catheter.
Your physician will want you to have a vessel mapping performed, which is a study of the blood vessels in the arms to help select the best veins for your access and decrease the chance for an unsuccessful surgery.
A good access will have a strong blood flow so you can get the full benefit of dialysis. And that means you can feel as well as possible and have a better life. It’s up to you to keep your access as healthy as possible. Taking good care of your access can help you have a quality life on hemodialysis.