The kidneys are two bean-shaped organs, which are each about the size of your fist. They are located at the back of your abdomen, on either side of your spine. The kidneys work like a filter, getting rid of extra fluid and waste material in the blood. When your kidneys lose the ability to filter and clean the blood, the fluid and waste can build up and poison the body. This is called kidney (renal) failure.
When the kidneys can no longer clean the blood, dialysis may be needed.The most common form of dialysis is called hemodialysis. In hemodialysis, blood from an artery in your arm flows through a thin plastic tube to a machine called a dialyzer. The dialyzer filters the blood, working like an artificial kidney, to remove the extra fluids and waste from the blood. The cleaned blood then flows out of the machine through another tube placed into a nearby vein in the same arm. Most people have 3 dialysis sessions every week. Each session lasts about 3 or 4 hours.
What is a vascular access site?
Before you can begin hemodialysis, there needs to be a way to remove the blood from the body (a few ounces at a time) and then return it. Your arteries and veins are usually too small, so you will need surgery to create a vascular access site.
There are 3 kinds of vascular access sites:
A fistula (also called an arteriovenous fistula or A-V fistula), which is made by joining an artery and a vein under the skin in your arm. (In most cases, the radial artery is joined to the cephalic vein.) When the artery and vein are joined, the pressure inside the vein increases, making the walls of the vein stronger. The stronger vein can then receive the needles used for hemodialysis. An A-V fistula usually takes 3 to 4 months to heal before it can be used for hemodialysis. The fistula can be used for many years.
An arteriovenous fistula or A-V fistula. Source: National Institutes of Health (NIH)
- A graft (also called an arteriovenous graft or A-V graft), which is made by joining an artery and vein in your arm with a plastic tube. The plastic tube is placed in a U-shaped loop under your skin, joining the radial artery to a vein near the elbow. The graft is usually ready to use about 3 weeks after the surgery. A-V grafts are usually not as long lasting as A-V fistulas, but a well-cared-for graft can last several years.
- A catheter, which is inserted into a vein in the neck or below the collarbone for short-term use until your A-V fistula or A-V graft is healed and ready to use. A catheter is not used for permanent access.
An arteriovenous graft or A-V graft.
Source: National Institutes of Health (NIH)
What to Expect
The operation will usually be scheduled at a time that is best for you and your surgeon, except in urgent cases. As the date of your surgery gets closer, be sure to tell your surgeon about any changes in your health. If you have a cold or the flu, this can lead to infections that may affect your recovery. Be aware of fever, chills, coughing, or a runny nose. Tell the surgeon if you have any of these symptoms.
Also, remind your surgeon about all of the medicines you are taking, especially any over-the-counter medicines such as aspirin or those that might contain aspirin. You should make a list of the medicines and bring it with you to the hospital.
It is always best to get complete instructions from your surgeon about the procedure, but here are some basics you can expect as a patient.
Before the Hospital Stay
You will most likely need some special tests to help the doctors decide the best type of vascular access and the best place to put the access. The most common tests are venography and Doppler ultrasound.
Most patients are admitted to the hospital the day before surgery or, in some cases, on the morning of surgery.
The night before surgery, you will be asked to bathe to reduce the amount of germs on your skin. After you are admitted to the hospital, the area to be operated on will be washed, scrubbed with antiseptic, and, if needed, shaved.
The medicine that makes you sleep during the operation is called "anesthesia." Because anesthesia is safest on an empty stomach, you will be asked not to eat or drink after midnight the night before surgery. If you do eat or drink anything after midnight, it is important that you tell your anesthesiologist and surgeon.
If you smoke, you should stop at least 2 weeks before your surgery. Smoking before surgery can lead to problems with blood clotting and breathing.
Day of Surgery
Before surgery, you may have an electrocardiogram (ECG or EKG), blood tests, urine tests, and a chest x-ray to give your surgeon the latest information about your health. You will be given something to help you relax (a mild tranquilizer) before you are taken into the operating room.
Small metal disks called electrodes will be attached to your chest. These electrodes are connected to an electrocardiogram machine, which will monitor your heart's rhythm and electrical activity. You will receive a local anesthetic to numb the area where a plastic tube (called a line) will be inserted in an artery in your wrist. An intravenous (IV) line will be inserted in a vein. The IV line will be used to give you the anesthesia before and during the operation.
After you are completely asleep, a tube will be inserted down your windpipe and connected to a machine called a respirator, which will take over your breathing. Another tube will be inserted through your nose and down your throat, into your stomach. This tube will stop liquid and air from collecting in your stomach, so you will not feel sick and bloated when you wake up. A thin tube called a catheter will be inserted into your bladder to collect any urine produced during the operation.
The surgeon leads the surgical team, which includes other assisting surgeons, an anesthesiologist, and surgical nurses.
The surgeon will then create the A-V fistula or the A-V graft in one of your arms. If you are right-handed, the fistula or graft will usually be placed in your left arm. If you are left-handed, the fistula or graft will usually be placed in your right arm.
You may use your arm as you normally do the same day as the procedure, but try to avoid heavy lifting.
If you had a catheter placed so you can have hemodialysis while your A-V fistula or graft is healing, you cannot get the catheter wet. An A-V fistula can get wet 24 to 48 hours after the procedure.
The A-V fistula procedure is an outpatient procedure, meaning you will not need to stay overnight in the hospital.
Patients who get an A-V graft will need to spend the night in the hospital for observation. Sometimes there is swelling or redness in the area where the graft is placed. The swelling will usually go away if you prop your arm on 1 or 2 pillows and keep your elbow straight and relaxed. Call your doctor if there are signs of severe redness or swelling, or if your arm becomes numb or weak.
Life After Vascular Access Surgery
Patients should avoid heavy lifting. Any injury to your arm can cause bleeding. When you go to the doctor, do not let anyone take your blood pressure, start an IV, or take blood from the arm with the A-V fistula or graft.
If you have an A-V graft, you should avoid wearing anything tight around your wrists or arms. Clothing or jewelry that is tight can decrease the blood flow in the graft, which can lead to blood clots within the graft. Also, do not lie or sleep on top of your arm.
You should always be able to feel blood rushing through your A-V graft. This feeling is called a thrill. You will also notice a slight vibration in the graft when you put your fingers on the skin over the graft.
See also on this site: Diabetes
See on other sites:
National Kidney and Urologic Diseases Information Clearinghouse
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Treatment Methods for Kidney Failure: Hemodialysis
Updated August 2012