Dialysis access refers to the creation of an entranceway into the bloodstream so that the blood can be cleansed by the dialysis procedure.
This entranceway is commonly located in the arm, the leg, or the neck.
The best type of dialysis access is provided by a fistula, in which an artery and vein are joined under the skin in a minor surgical procedure.
Hemodialysis, also called dialysis, is a procedure in which blood is circulated through a machine that cleans it of impurities and regulates fluid and chemical balances. To prepare for long-term dialysis, a surgeon crafts an easy-to-access portal, called the dialysis access, into the bloodstream under the skin. This portal allows blood to be removed and returned speedily and efficiently during the dialysis.
Individuals who suffer from sudden kidney failure begin dialysis using a catheter, a soft, thin, flexible tube that is inserted into a large vein in the neck, the chest, or the leg near the groin. Catheters rarely are a permanent solution. They can clog, become infected, or dislodge. As a result, the physician will recommend the creation of a permanent portal under the skin. Creating the portal is considered minor surgery.
WHEN IS DIALYSIS ACCESS INDICATED?
Dialysis access is crucial for those whose kidneys have failed and who must undergo regular hemodialysis to survive.
WHAT TO EXPECT
A surgeon creates a fistula by joining an artery and a vein under the skin, typically in the forearm.
The most popular kind of portal is called a fistula. Because it is less likely to form clots or become infected, a fistula is considered the best choice of access to the bloodstream. If properly maintained, a fistula may last years or even decades.
The surgery to create the fistula is performed on an outpatient basis with local anesthetic. During the surgery, after making a single incision, the physician joins an artery and a vein under the skin, typically in the forearm. The vein is divided and the end leading back to the heart is sewn to a hole in the side of the artery. Thus, blood flows both through the fistula into the visible veins and down the arteries into the hand. About one-third of fistulas fail within weeks after surgery, so a large vein must be selected for the surgery. Some individuals may not be good candidates if their veins are too small.
For persons ineligible for a fistula, a graft may be created to connect an artery to the vein using a piece of vein from the person's leg, a section of a cow's carotid artery, or a piece of synthetic material. This procedure is performed with a combination of local anesthetic and sedation or, in some cases, a general anesthesia. While a graft can last for years, they tend to be more problematic, developing clots or becoming infected.
Immediately following the operation, the patient should:
Keep the arm raised above the heart to reduce swelling and discomfort;
Keep the incision dry for at least two days; and
Avoid scrubbing the incision until the sutures are removed.
The site of the incision may be sore, but over-the-counter painkillers should suffice for the pain.
To care for the access site in the weeks following surgery:
Avoid heavy lifting or rigorous activity;
Report any worsening pain, swelling, or bleeding to the physician; and
Alert the physician in the event of fever higher than 101 degrees F.
About one-third of all new accesses fail, typically because of clotting (thrombosis). In the event of clotting, the fistula or graft is surgically fixed in a procedure called a thrombectomy, a procedure where the graft or fistula is opened and the clots are removed with a special kind of catheter. When the clots cannot be removed, a new graft or fistula is needed.
Infection is another complication, which may be treated with antibiotics.
Protecting the portal site is crucial for someone on dialysis. To maintain a clean a safe access site, physicians recommend that patients:
Check the site several times a day to ensure that the access is functioning.
Do not carry heavy items with the arm that has the access.
Do not sleep on the arm with the access site.
Do not wear any clothing or jewelry that binds that arm.
Do not let anyone draw blood from that arm.
Do not allow injections to be given into the fistula or graft.
Do not permit anyone to measure blood pressure in that arm.
Keep the site of the fistula or graft clean using an antibacterial soap.
Observe the site after dialysis for swelling, bleeding, or infection.
Do not use any creams and lotions over the site of the fistula or graft.