What is dialysis access?
Dialysis access (commonly referred to as an AV fistula or graft) is an entranceway into your bloodstream that lies completely beneath your skin and is easy to use. The access is usually in your arm, but sometimes in the leg, and allows blood to be removed and returned quickly, efficiently, and safely during dialysis or, less commonly, for other procedures requiring frequent access to your circulation.
Dialysis, also called hemodialysis, is the most common treatment for kidney failure. A dialysis machine is an artificial kidney designed to remove impurities from your blood. During dialysis, physicians use the dialysis access to remove a portion of your blood to circulate it through the dialysis machine so it can remove impurities and regulate fluid and chemical balances. The purified blood is then returned to you, again through the dialysis access.
Creating the access portal is a surgical procedure. There are two types of portals placed completely under the skin:
- Fistula, which we construct by joining an artery to a vein
- Graft, which is a man-made tube, consisting of a plastic or other material, that we insert under the skin to connect an artery to a vein
For both fistulas and grafts, the connection between your artery and vein increases blood flow through the vein. In response, your vein stretches and becomes strengthened. This allows an even greater amount of blood to pass through the vein and allows your dialysis to proceed efficiently. In the weeks after surgery, the fistula begins to mature. The vein increases in size and may look like a cord under your skin. The whole process of maturation, which is a beneficial feature that permits the blood flow to increase in the fistula, typically takes 3 to 6 months. Some fistulas may take as long as a year or more to develop fully, but this is unusual. Once matured, a fistula should be large and strong enough for dialysis technicians and nurses to insert the large dialysis needles easily. If it fails to mature in a reasonable period of time, however, you may need another fistula.
A graft placed between an artery and vein can usually be used for dialysis within 2-6 weeks, when it is healed sufficiently. Usually fistulas are preferred to grafts, however, because fistulas are constructed using your own tissue, which is more durable and resistant to infection than are grafts. However, if your vein is blocked or too small to use, the graft provides a good alternative.
What happens during dialysis access?
Typically you will have the procedure on an outpatient basis. Most often, you will first be sedated and then we will numb the area where the fistula or graft will go. In some cases, your anesthesiologist may give you supplemental sedation or put you to sleep.
Depending upon the quality of your artery and vein, we will try to construct the fistula with one incision using the forearm of the arm that you do not use as frequently. For example, if you’re left handed, we typically (but not always) will place the fistula in your right arm, if possible. To perform the surgery, we join a large vein under the skin to an artery nearby. If you cannot receive a fistula because the vein is too small or blocked, we may construct a graft using a tube of man-made, plastic material.
What can I expect after dialysis access?
After the operation, you should initially keep the access area raised above your heart to reduce swelling and pain. Your surgeon may recommend an over-the-counter painkiller to relieve pain, if necessary.
Following the suggestions below will help you keep your new access site working properly in the weeks after the surgery:
- Keep the incision dry for at least 2 days after the procedure and do not soak or scrub the incision until it has healed
- Avoid lifting more than about 15 pounds or other activities that stress or compress the access area, such as digging
- Report pain, swelling, or bleeding immediately to your physician, especially if these symptoms are becoming worse. Some pain or swelling is common and not worrisome if decreasing, but you should tell your physician if you have bleeding, drainage or a fever higher than 101 degrees Fahrenheit
You may initially feel some coolness or numbness in the hand with the fistula. These sensations usually go away in a few weeks as your circulation compensates for the fistula. However, if these sensations are severe or don’t disappear, tell us as soon as possible, because the fistula may be causing too much blood to flow away from your hand, a condition physicians call a “steal.”
You should perform exercises to grow and strengthen your fistula, after the pain from the surgery decreases, to make dialysis faster and easier. We recommend squeezing a soft object using the hand on the arm in which the fistula was placed.
Are there any complications?
Complications with dialysis access include, in addition to “steal” discussed above, clotting, narrowing, aneurysm formation in the access itself, infection, and bleeding.
What can I do to stay healthy?
Protecting the dialysis access is crucial for you. The following tips will help you care for a fistula or a graft:
- Check several times each day to make sure the access is functioning. You should be able to feel a vibration in the fistula called a “thrill.” Your physician or dialysis center staff will show you how to do this
- Monitor any bleeding after dialysis. If the graft seems to bleed longer than usual from the needle sites, you should notify your dialysis center staff
- Do not carry heavy items with the arm that has the access
- Do not sleep on that arm
- Do not wear any clothing or jewelry that binds that arm
- Do not let anyone draw blood or measure blood pressure from that arm
- Do not allow injections to be given into the fistula or graft
- Keep the site of the fistula or graft clean
- After dialysis, monitor the access for signs of infection, such as swelling or redness
- Do not use any creams and lotions over the site of the fistula or graft