An AV fistula is a surgical connection made between an artery and a vein, created by a vascular specialist. An AV fistula is typically located in your arm, however, if necessary it can be placed in the leg.
With an AV fistula, blood flows from the artery directly into the vein, increasing the blood pressure and amount of blood flow through the vein. The increased flow and pressure causes the veins to enlarge. The enlarged veins will be capable of delivering the amount of blood flow necessary to provide an adequate hemodialysis treatment.
AV fistulas are the preferred vascular access for long-term dialysis because they last longer than any other dialysis access types, are less prone to infection and clotting, and can be relied upon for predictable performance. The first step in AV fistula creation is to evaluate your blood vessels veins and arteries , to ensure they are healthy enough to support a fistula.
The first step in the evaluation will be a physical examination of your arms performed by your vascular specialist. Early detection of an arteriovenous fistula may make your condition easier to treat. It also may reduce your risk of developing complications, including blood clots or heart failure.
In addition to certain genetic or congenital conditions, the following risk factors may make you more likely to develop an arteriovenous fistula:. Left untreated, an arteriovenous fistula can cause complications, some of which can be serious.
These include:. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Overview Arteriovenous fistula Open pop-up dialog box Close. Arteriovenous fistula An arteriovenous AV fistula is an abnormal connection between an artery and a vein in which blood flows directly from an artery into a vein, bypassing some capillaries.
Request an Appointment at Mayo Clinic. Our vascular surgeons are internationally recognized for their development of new techniques for dialysis access. They work closely with the nephrologists, who diagnose and treat kidney disease, and interventional radiologists, who provide minimally invasive image-guided diagnosis and treatment of disease.
The result is a course of treatment that fits the needs of each patient. Skip to Main Content. Print Share Download. What is an AV fistula? How is an AV fistula used during dialysis? When does AV fistula surgery take place? Are there alternatives to AV fistula? You receive a local anesthetic numbing medicine at the proposed site along with IV sedation to relax you. Discomfort is minimal and you may even fall asleep during the 1 to 2 hour-long procedure.
The surgical incision is usually only 2 to 4 inches long. Generally you are able to return home later that same day. The fistula usually requires from 8 to 12 weeks for the veins to dilate prior to initial use. Despite excellent technique, some patients may suffer complications from the AV fistula procedure. An unusual, but serious, complication can occur when the arterial blood that is supposed to reach the hand is redirected through the fistula.
Sometimes the fistula functions so well that not enough blood reaches the hand causing ischemia lack of oxygen. This condition is called "steal" and usually requires surgical procedure to establish a new access at a different site.
Unfortunately not every patient is suitable for an AV fistula. If the veins are damaged or too small, the AV fistula will not mature, or worse yet, clot.
In this situation, the dialysis access team recommends other options that may include another fistula at a different site, catheter placement or an arteriovenous graft.
An arteriovenous graft is another form of dialysis access, which can be used when people do not have satisfactory veins for an AV fistula. In this procedure, surgeons connect an artery and a large vein in your elbow or armpit using a graft made of synthetic fabric that is woven to create a watertight tube. The graft is frequently used to repair blood vessels or perform blood vessel bypass when blockages occur, and also works very well to establish dialysis access.
Creating an AV graft is a surgical procedure, which requires a small incision at the proposed site. Surgeons sew the graft to an artery and tunnel it, just under the skin, creating a loop back to the starting incision where it is then sewn to a vein. The long loop gives the dialysis nurses space to access the graft. AV grafts can be safely used in about two weeks, as no maturation of the vessels is necessary.
Grafts have a lifespan of approximately 2 to 3 years but can often last longer. However, AV grafts can be more troublesome than AV fistulas. Blood is more likely to clot in grafts because they are made of prosthetic foreign material. When this happens, interventional procedures can remove the clot and restore blood flow for dialysis. Complications related to AV grafts are similar to those with AV fistulas: bleeding, thrombosis clotting , steal and because of the prosthetic nature of the graft, infection.
Infected grafts must be removed immediately and a new access site developed once the infection clears. Surgeons must place a long silicone-based tube called a Tenckhoff catheter into the abdomen before peritoneal dialysis can begin. The surgeon in the operating room positions the tube using a local anesthetic and IV sedation. Making a small incision in your abdomen, the surgeon advances the tube deep into the lower part of your peritoneal cavity the membrane lining the inside of the abdomen , tunnels the tube under the skin for several inches, brings the tube up through the skin at a different location, and then surgically closes the initial incision.
A sterile dressing covers the catheter that remains outside of the body.
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