Renal Failure/Dialysis Access
If you have failing kidneys, you will need dialysis.
Dialysis allows a machine to gain access into your circulation and filter your blood since your kidneys no longer can do this. Dialysis access is an entranceway into your bloodstream that lies completely beneath your skin and is easy to use. This access is usually in your arm, and allows blood to be filtered and returned during dialysis.
Creating a dialysis access procedure can be done in one of three ways:
Fistula: a surgeon connects your own artery and vein
Graft: a surgeon connects your own artery and vein using an artificial tube under the skin for dialysis
Catheter: a surgeon inserts a tube into your vein that sticks out of your skin that can be used for dialysis
For both fistulas and grafts, the connection between your artery and vein increases blood flow through the vein. Because of this, your veins stretch and become stronger, allowing even more blood to flow and thus making dialysis even better. After surgery, fistulas begin to “mature” and grow and stretch. The whole maturation process typically takes 3 to 6 months. Some fistulas may take even longer to fully develop. Once mature, 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 2-3 weeks, when it is healed sufficiently.
A fistula is preferred because of the lower infection rate since it only uses your own tissue. In addition, fistulas last longer. Not everyone has large enough veins and arteries, however, to make a fistula and therefore grafts are used as well.
Catheters are never preferred as they have the highest infection rate. However, they can be placed and used immediately and some patients need dialysis emergently and cannot wait the weeks to months until grafts or fistulas can be used.