Dialysis Access Surgery
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. Patients with chronic kidney disease (CKD) may be referred to a vascular surgeon when they reach stage 4 or 5 CKD.
Dialysis (also known as 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. It is necessary to have access to large amount of blood (much more than a regular IV catheter) in order to have hemodialysis. That is why people have to have surgery in order to obtain what we call dialysis access.
Another type of dialysis is called peritoneal dialysis. This performed by placing a catheter through the skin and into the peritoneal or abdominal cavity. One benefit of peritoneal dialysis is that it can be done at home, and you do not have to go to a hemodialysis clinic three times a week in order to have dialysis. Peritoneal dialysis works by exchanging or leaching water, salts and wastes out of the body and bloodstream through exchanges of fluid in the abdominal cavity.
What are the types of hemodialysis access ?
There are several types of access. 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
- A temporary catheter: this is only for short-term access when no other access is available.
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 large, healthy veins. Blocked arteries, narrow veins, and veins scarred from frequent placement of intravenous catheters (narrow tubes inserted to administer medicine) and injections can prevent you from having a fistula access. In such cases, you may be recommended for a graft access procedure. However, a 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 grafts for several reasons including lower risk of infection and lower risk of the access clotting.
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 and nephrologist may order an ultrasound, venogram (imaging test to determine blood flow through the veins) or an arterial 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 Arms are preferred more than legs for placement of the dialysis access as legs are more susceptible to atherosclerosis (hardening of arteries) and infection.
You will be instructed on dietary and medication restrictions/modifications by your doctor before your procedure. You will 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. General anesthesia is often used during the procedure. Depending on the health of your artery and vein, your surgeon will try to place the access on your less dominant arm.
A fistula is created by connecting one of your veins (usually the cephalic or basilic veins) to one of the arteries in your arm. Some of the blood flow that was going towards your hand will now be going up into the fistula and eventually to your heart. Too much blood flow can result in a situation where the nerves of the hand are jeopardized due to not receiving enough oxygen. This is called STEAL SYNDROME and it can be a surgical emergency.
Your surgeon may insert a graft instead, if you cannot have a fistula placed. The graft may be man-made, or rarely, some other material. 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.
A peritoneal dialysis catheter is also placed under general anesthesia. A small incision is placed (usually around the belly button) and a camera is inserted into the abdominal cavity. A brief exploration is performed and the catheter is placed using an additional two to three tiny incisions in your skin. Sometimes after we look around with a camera, we are unable to place the catheter most often due to scar tissue. That is why if a patient has had multiple abdominal surgeries, it may be impossible to place a peritoneal dialysis catheter.
What can you expect after the dialysis access?
Following the hemodialysis 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. However, pain in your hand should be reported to your surgeon immediately. This may represent steal syndrome (discussed above) and may result in permanent disability if not treated promptly.
Fistulas 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- 3 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 steal. Some of the other possible complications include, but are not limited to:
- Clotting, narrowing, weakening of the artery, leading to aneurysm formation in the access itself
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 drawing blood or measuring blood pressur`e from the arm.
- Avoid administering injections into the fistula or graft.
- Always keep the access site clean.
- There are NO ACTIVITY restrictions (within reason—please do not abuse your arm) for the arm that has the access. Many people including nurses, other doctors, etc. may tell you to “baby” your arm, but it is not necessary.