What is a Dialysis Access?
The kidneys function to balance salt, water and minerals in the blood and remove waste from your body in the form of urine. Kidney failure is a condition where the kidneys are damaged and cannot filter blood properly. This causes a build-up of fluids and wastes to dangerously high levels that may result in a coma and even death of an individual if left untreated.
Dialysis (hemodialysis) is the most common treatment for renal failure. The dialysis machine acts like an artificial kidney, removing impurities from the blood and regulating fluid and chemical balances. During dialysis, blood is removed from your body, passed through the dialysis machine and the purified blood from the dialysis machine is returned back to your body.
The dialysis access is a portal positioned completely under the skin to provide a convenient entryway into your bloodstream. The access is usually in your arm or sometimes in your leg and allows for quick removal and return of blood during dialysis.
What are the Types of Access portals?
There are two types of access portals. They include:
- Fistula: created by connecting an artery to a vein
- Graft: an artificial tube made of plastic or other material used to connect an artery to a vein
The connection between your artery and vein increases the flow of blood through your vein. Over time your vein stretches and strengthens and allows for more blood to pass through. This helps to carry on dialysis more efficiently.
What are the Indications for a Fistula or Graft Access procedure?
You may be a good candidate for a fistula if you have healthy veins. Blocked arteries, narrow veins, and veins scarred from the frequent placement of intravenous catheters (narrow tubes inserted to administer medicine) and injections can prevent you from having fistula access. In such cases, you may be recommended for a graft access procedure. However, graft access may not be advised if you have an ongoing infection due to the possibility of the infection spreading to the graft as well. Fistulas are preferred over graft access portals as fistulas last for 3-7 years.
How do you Prepare for a Dialysis Access Procedure?
Your surgeon first selects the access site. Your medical history for arm or leg artery disease may be reviewed. Your surgeon may recommend an X-ray, ultrasound, venogram (imaging test to determine blood flow through the veins) or a pulse volume recording test (blood pressure cuff and ultrasound to determine arterial blood flow) to determine the size of your veins and evaluate the flow of blood in your arteries. These tests are conducted to ensure that your vascular surgeon does not choose an area in the body with reduced blood flow as blood circulation will be insufficient. Arms are preferred more than legs for placement of the dialysis access as legs are more susceptible to atherosclerosis (hardening of arteries).
You will be instructed on dietary and medication restrictions/modifications by your doctor before your procedure. You may be asked not to eat or drink anything 8 hours before the procedure.
How is a Dialysis Access Procedure Performed?
The procedure is typically performed on an outpatient basis. You will be made to sleep throughout the procedure. The site of the access will be numbed. Depending on the health of your artery and vein, your surgeon will place the access on your less dominant arm.
Your surgeon makes a small incision, divides a large vein in your arm and stitches it to an opening made in a nearby artery. This causes blood to flow down the artery into the hand, as normal while some faster-moving blood flows back to the heart through the vein that is attached to the artery. Other veins and arteries in the hand-carry blood to the hand; therefore, there is no interruption in the normal flow of blood.
Your surgeon may insert a graft instead, if you cannot receive a fistula. The graft may be man-made, or rarely, a section of vein from your leg or artery from a cow. Your surgeon will stitch one end of the graft to one of your veins and connect the other end to an artery. The graft may be positioned straight or as a loop under the skin of your lower arm, upper arm, or sometimes, in your leg.
What can you expect after the Dialysis Access?
Following the dialysis access procedure, you will be instructed to keep the access area elevated above the level of your heart to reduce post-procedure swelling and pain. If required, you will be prescribed medications to control your pain. It is quite normal to feel some coolness or numbness in your operated arm. These sensations will wear off in a few weeks. You will be taught exercises to strengthen your fistula.
Fistula access portals may take weeks to months to mature, i.e., the vein grows bigger and stronger to accommodate the increased flow of blood. A graft placed between an artery and vein can usually be used for dialysis within 2-6 weeks, when it is healed sufficiently. Your doctor will let you know when the access is ready for dialysis.
Some pain and swelling is common. However, contact your doctor immediately if you experience fever higher than 101° F or increased pain, swelling, and/or bleeding.
Are there any Complications Associated with Dialysis Access?
In some cases, a fistula may cause too much blood to flow away from the hand - a condition called a steal. Some of the other possible complications include:
- Clotting, narrowing, weakening of the artery, leading to aneurysm formation in the access itself
- Bleeding
- Infection
How should you Care for your Fistula or Graft?
The following tips can help you protect your dialysis access and stay healthy:
- Check for normal functioning, i.e. for a vibration in the fistula called a “thrill”, several times a day. Your doctor or dialysis staff will educate you on this.
- Inform your doctor or dialysis staff for any unusual bleeding from the needle sites after dialysis.
- Avoid heavy lifting or sleeping on the arm with the dialysis access.
- Do not wear tight clothing or jewelry that may put pressure on the arm.
- Avoid drawing blood or measuring blood pressure from the arm.
- Avoid administering injections into the fistula or graft.
- Always keep the access site clean.
