Dialysis Access

Your kidneys remove waste from your blood. When your kidneys fail, they can no longer do this important work. Hemodialysis takes over the job of keeping your blood clean. If you have chronic kidney failure and need long-term hemodialysis, you may require dialysis access. There are different types of accesses. An access is usually created 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 minor surgical procedure. There are two types of portals placed completely under the skin.

Types of Access

  • Fistula, which your vascular surgeon constructs by joining an artery to a vein.
  • Graft, which is a man-made tube, consisting of plastic or other material, that your vascular surgeon inserts 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 appear like a cord under your skin. The whole process of maturation, typically takes 3-6 months. Some fistulas may take as long as a year to develop, but this is unusual. Once matured, a fistula should be large enough for dialysis technicians and nurses to insert the large dialysis needles easily.

A graft placed between an artery and vein can usually be used for dialysis within 2-6 weeks, when it has 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 is a good alternative.

Surgery to create an access

Typically you will have the procedure on an outpatient short stay basis. Most often, you will be sedated and then your surgeon will numb the area where the fistula or graft will go. In some cases, the anesthesiologist may give you supplemental sedation or put you to sleep.

Depending on the quality of your artery and vein, your surgeon 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, your physician will try to place the fistula in your right arm, if possible. To perform the surgery, your physician joins a large vein under the skin to a nearby artery. The physician divides your vein and sews it to an opening made in the side of the artery. As a result, the blood flows down the arteries into the hand, as usual, and also some of this faster moving blood flows into the veins that lead back to your heart. The blood that normally in your divided vein goes back to the heart through other veins, and there is usually plenty of blood remaining to your artery to supply the hand.

If you cannot receive a fistula because the vein is too small or blocked, your physician may construct a graft using man-made plastic material. Less commonly, your physician may also choose to use a piece of vein from your leg, or a section of artery from a cow (Bovine graft) as an alternative graft material.

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. You should perform exercises to grow and strengthen your fistula, after the pain of surgery decreases, to make dialysis faster and easier. Your physician may have you use a soft squeeze ball several times a day on the arm in which the fistula was placed.

Dialysis Catheters

Sometimes access portals can take weeks or months until they are ready for dialysis use. Until the portal is ready, you may have to use a catheter for dialysis. These are inserted into a large vein under the collarbone or in the neck and covered with a gauze dressing.

Monitor your access

  • After surgery, check several times a day to make sure your access is functioning. You should be able to feel a vibration in the fistula called a “thrill” or “bruit”.
  • Do not carry heavy items, with the accessed arm.
  • Do not have IV’s, blood pressures, injections, or blood drawn from that arm.
  • Do not sleep on that arm.
  • Do not wear any constrictive clothing or jewelry on that arm.
  • After dialysis, monitor the access for any bleeding, signs of infection such a swelling or redness.