Creating an Arteriovenous Fistula

Arteriovenous fistula

The best way to establish long-term hemodialysis access is to construct an arteriovenous (AV) fistula. An AV fistula is a surgically placed "shunt" whereby an artery is directly sutured to a vein. An artery is a high-pressure tube that carries blood away from the heart and delivers nutrients and oxygen to the tissues. A vein is a low-pressure system that returns blood back to the heart to begin the process all over again.

When an artery and a vein are sewn together, the high-pressure blood does not reach the tissues but is diverted instead into the vein and back to the heart. Over time the vein will dilate, which is often called maturation. At maturation, nurses can easily access the vein with needles for dialysis therapy.

AV Fistula Surgery
A surgeon usually performs the procedure in the operating room. The patient receives a local anesthetic (numbing medicine) at the proposed site along with sedation. Surgeons can create an AV fistula in the wrist, forearm, inner elbow or upper arm. Discomfort is minimal and the patient may even fall asleep during the procedure, which can take from one to two hours. The surgical incision is usually only two to four inches long. Generally patients are able to return home later that same day. The fistula usually requires from eight to 12 weeks for the veins to dilate prior to initial use. When properly constructed, and with satisfactory maturation, an AV fistula can function for many years.

What is an Arteriovenous Graft?

One kind of AV 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 the elbow or armpit using a graft made of synthetic fabric that is woven to create a watertight tube. Frequently used to repair blood vessels or perform blood vessel bypass when blockages occur in the legs or abdomen, this tube/graft also works very well to establish dialysis access.

AV Graft Surgery

Creating an AV graft is a surgical procedure, which requires a small incision at the proposed site. The graft is sewn to an artery and tunneled, 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 required. Grafts have a lifespan of approximately two to three 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

Dialysis Access Center

Dialysis access Coordinator

The Dialysis center was developed under the guidance of Dr Kirksey in a collaborative effort with talented nephrologists. Our goal is to provide prompt, state-of-the-art care to patients who need to have a dialysis access created or repaired before undergoing or continuing hemodialysis or peritoneal dialysis.
There are several ways to establish dialysis access. The patient’s nephrologist (kidney doctor) and surgeon decide which type of access will provide the best long-term dialysis function for each individual.

Transplant surgeons specialize in all types of dialysis access surgery, including:

* placement of arteriovenous (AV) fistulae and grafts, types of vascular access for hemodialysis that involve connecting arteries to veins, sometimes with foreign (prosthetic) graft materia
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* placement of tunneled central venous dialysis catheters (permanent catheters that are tunneled under the skin to enter the venous system for hemodialysis)

* catheter placement (tunneling a long silicone tube into the abdomen) for peritoneal dialysis

In addition to access services for patients new to dialysis, surgeons also are available for immediate repair for patients who experience urgent problems such as blood clots, infection or pseudoaneursyms (a bulge in a graft wall).

Frequently Asked Questions About Dialysis Access

What is dialysis access surgery?
Dialysis, either hemodialysis or peritoneal dialysis, is a life-saving procedure that replaces kidney function when the organs fail. In order to be treated with dialysis, physicians must establish a connection between the dialysis equipment and the patient’s bloodstream. Dialysis access surgery creates the vascular opening so a needle can be inserted for hemodialysis or an abdominal catheter inserted for peritoneal dialysis.

There are several ways to establish dialysis access. The patient’s nephrologist (kidney doctor) and surgeon work with the patient to decide which type of access will provide the best long-term dialysis function for each individual.

Who performs the dialysis access procedure?
Establishing dialysis access is an invasive (surgical) procedure that can be performed by nephrologists, interventional radiologists and surgeons. A team effort helps ensure excellent patient service, care and long-term results. Our center is staffed with leading vascular surgeon, vascular interventional specialist and nephrologists in the community. The team also consists of nurse practitioners and social workers. All of these individuals meet regularly to ensure that patients receive the best that each specialty has to offer.

What type of dialysis access procedure is necessary for hemodialysis?
Hemodialysis circulates blood through a machine outside of the body to remove toxins and excess fluid and to correct electrolytes like potassium, sodium, phosphate and calcium, to name a few. The machine then pumps the cleansed blood back into the body. The blood leaves and returns to the body through a catheter, a long piece of silicone tubing placed in the neck, chest or leg. A catheter is used to establish quick vascular (bloodstream) access, when an individual needs to begin dialysis therapy immediately. Or bloodstream access can also be accomplished by placing two needles into a fistula or a graft that has been previously constructed for this purpose.

How are catheters placed?
Catheters come in two varieties, temporary and permanent. Temporary catheters penetrate the skin and directly enter the venous system. Permanent catheters also penetrate the skin, but are then tunneled under the skin for several inches before they finally enter the venous system. Tunneling the catheter reduces the risk of infection.

Any medical professional can place a temporary catheter with minor discomfort, using a local anesthetic and minimal sedation. However a surgeon in the operating room, or an interventional radiologist in the interventional suite, must place permanent catheters. During the procedure, physicians use fluoroscopy (continuous X-rays) to be sure the catheter is positioned correctly. Permanent catheters require a minor procedure for removal whereas temporary catheters can simply be pulled out.

Are catheters safe for long-term use?
Prolonged catheter access can lead to multiple complications, the most common of which is infection. Even with excellent placement technique, bacteria can enter the bloodstream directly through the catheter during dialysis. Bacteria from the skin can also move down the catheter and enter the bloodstream. With catheter infection people develop high fevers and chills and need prompt treatment. Generally physicians must remove the catheter so the body can fight the infection.

Another possible complication from long-term catheter use is damage to the main chest vessels, which can lead to stenosis (narrowing) or thrombosis (clotting) of the veins. This type of damage is usually permanent and the vessel—as well as the arm on the side of the vessel— may no longer be useable for dialysis access.
Because of these potential complications, physicians make every effort to avoid prolonged catheter use.

What is an AV fistula?
The best way to establish long-term hemodialysis access is to construct an arteriovenous (AV) fistula. An AV fistula is a surgically placed "shunt" whereby an artery is directly sutured to a vein. An artery is a high-pressure tube that carries blood away from the heart and delivers nutrients and oxygen to the tissues. A vein is a low-pressure system that returns blood back to the heart to begin the process all over again.
When an artery and a vein are sewn together, the high-pressure blood does not reach the tissues but is diverted instead into the vein and back to the heart. Over time the vein will dilate, which is often called maturation. At maturation, nurses can easily access the vein with needles for dialysis therapy.

Where are AV fistulas located and how long do they last?
Surgeons can create an AV fistula in the wrist, forearm, inner elbow or upper arm. When properly constructed, and with satisfactory maturation, an AV fistula can function for many years.

How is the AV fistula procedure performed?
A surgeon usually performs the procedure in the operating room. The patient receives a local anesthetic (numbing medicine) at the proposed site along with sedation. Discomfort is minimal and the patient may even fall asleep during the procedure, which can take from one to two hours. The surgical incision is usually only two to four inches long. Generally patients are able to return home later that same day. The fistula usually requires from eight 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. Infection, bleeding, arm swelling and/or tingling in the fingers may occur postoperatively. 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 intervention and establishing a new access at a different site.

Can anyone have an AV fistula?
Unfortunately not every patient is suitable for an AV fistula. Numerous needlesticks for IV fluids, blood work and/or medicines can damage veins over time, creating scar tissue, which can make creation of an AV fistula impossible. 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.

What is 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 the elbow or armpit using a graft made of synthetic fabric that is woven to create a watertight tube. Frequently used to repair blood vessels or perform blood vessel bypass when blockages occur in the legs or abdomen, this tube/graft also works very well to establish dialysis access.

How is the AV graft created?
Creating an AV graft is a surgical procedure, which requires a small incision at the proposed site. The graft is sewn to an artery and tunneled, 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 required. Grafts have a lifespan of approximately two to three 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.

What type of dialysis access procedure is necessary for peritoneal dialysis?
A Tenckhoff catheter, a long silicone-based tube, must be placed into the abdomen before peritoneal dialysis can begin. The surgeon in the operating room positions the tube using a local anesthetic and sedation. Making a small incision in the abdomen, the surgeon advances the tube deep into the lower part of the peritoneal cavity, 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.
Tunneling the catheter reduces the likelihood of infection in the peritoneal cavity. Patients are allowed to go home the same day of surgery. Once the incisions heal, anywhere from two to four weeks, peritoneal dialysis can begin.

What types of complications are possible from the Tenckhoff catheter?
Complications related to catheter placement may include bleeding and damage to large or small intestines or abdominal blood vessels. Although usual, these issues could require additional corrective surgery. Once peritoneal dialysis begins, complications related to repeated use of the catheter include peritonitis, which is an infection of the peritoneal cavity. Peritonitis, which can be quite serious, is usually associated with abdominal pain, fevers and cloudy peritoneal dialysis solution. If the infection does not respond to antibiotic treatment, then it may be necessary to remove the catheter.

When should dialysis access surgery take place?
The best approach is to undergo dialysis access surgery well before dialysis therapy needs to begin, which will give the access site time to mature and avoid the use of temporary catheters. Sometimes patients need a temporary catheter while they are waiting for their permanent AV fistula or AV graft to heal.

How does the dialysis access team evaluate individuals for long-term success?
The team, which includes a vascular surgeon, vascular interventional specialists and nephrologist, perform an extensive physical exam to identify satisfactory vessels to construct the AV fistula or graft. The team may request additional studies such as ultrasounds or even dye studies of the blood vessels in the extremities. After the team decides on the appropriate type of access, then location is the next selection. Typically surgeons construct hemodialysis access in the forearm of the non-dominant hand. If this site is not suitable then the team may choose to use the forearm of the dominant hand or the upper arm of the non-dominant hand, above the elbow.

What is Dialysis Access?

When kidneys fail, kidney replacement therapy—either dialysis or renal transplantation—must begin. There are two forms of dialysis: hemodialysis and peritoneal dialysis .

Dialysis access is the surgical process of establishing a connection between the patient’s bloodstream and an artificial kidney (dialysis machine). Surgeons perform dialysis access surgery for patients who need dialysis replacement therapy because their kidneys have failed.
With hemodialysis, nurses connect the patient to the dialysis machine via a needle and tubing, and blood is continuously passed through the machine’s artificial membrane to remove toxins and excess fluid. Hemodialysis requires four to five hours per treatment, and is generally performed three days each week.

In peritoneal dialysis, patients put several gallons of a special fluid into their abdomen through a surgically placed tube. Toxins and extra fluid leak into the abdominal (peritoneal) cavity and are removed when the fluid is drained from the abdomen. Peritoneal dialysis requires several exchanges of fluid per day, but people may do this at home or at work. No matter which type of dialysis is chosen, dialysis access surgery is always necessary to establish a connection to the bloodstream or the abdominal cavity.

Dialysis Access Surgery and Possible Complications:

Access Surgery as Soon as Possible
The best possible approach for people who must begin renal replacement therapy is to undergo dialysis access surgery well before dialysis therapy needs to begin, to give the access site time to mature and to avoid the use of temporary catheters. Sometimes patients need a temporary catheter while they are waiting for their permanent AV fistula or AV graft to heal.
Access for Hemodialysis

The physician team, which includes a nephrologist, interventional radiologist and surgeon, perform an extensive physical exam to identify satisfactory vessels to construct the AV fistula or graft. The team may request additional studies such as ultrasounds or even dye studies of the blood vessels in the extremities. After the team decides with the patient about the appropriate type of access, then location is the next selection. In the operating room, while the patient is sedated, surgeons typically construct hemodialysis access in the forearm of the non-dominant hand. If this site is not suitable then the team may choose to use the forearm of the dominant hand or the upper arm of the non-dominant hand, above the elbow.

Access for Peritoneal Dialysis
A surgeon must place a Tenckhoff catheter, a long silicone-based tube, into the abdomen before peritoneal dialysis can begin. Tunneling the catheter reduces the likelihood of infection in the peritoneal cavity.

Access-Related Complications:

Infection
Prolonged catheter access can lead to multiple complications, the most common of which is infection. Even with excellent placement technique, bacteria can enter the bloodstream directly through the catheter during dialysis. Bacteria from the skin can also move down the catheter and enter the bloodstream. With catheter infection people develop high fevers and chills and need prompt treatment. Generally physicians must remove the catheter so the body can fight the infection.

Stenosis and Thrombosis
Another possible complication from long-term catheter use is damage to the main chest vessels, which can lead to stenosis (narrowing) or thrombosis (clotting) of the veins. This type of damage is usually permanent and the vessel—as well as the arm on the side of the vessel—may no longer be useable for dialysis access.

Because of these potential complications, physicians make every effort to avoid prolonged catheter use.

AV Fistula Issues
An AV fistula is a surgically placed "shunt" whereby an artery is directly sutured to a vein. Over time the vein will dilate, which allows easy access with needles for hemodialysis therapy. Blood flow through the surgically-created fistula is not as smooth as through normal blood vessels. This turbulence (not unlike water passing over stones and rocks) can be felt through the skin as a buzzing sensation, or "thrill," which also creates a noise, or "bruit," which physicians can hear with a stethoscope. If there is no thrill or buzz, it may mean the fistula is blocked or not working for other reasons and patients should seek immediate medical attention.

Despite excellent technique, some patients may suffer post-operative complications from the AV fistula procedure: infection, bleeding, arm swelling and/or tingling in the fingers. In addition, 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 intervention and establishing a new access at a different site.
Patients should always report any changes they notice in their fistula to the BIDMC dialysis access nurse coordinator who will alert the transplant surgeons and schedule immediate repair for serious complications.

Tenckhoff Catheter Complications
Complications related to Tenckhoff catheter placement for peritoneal dialysis may include bleeding and damage to large or small intestines or abdominal blood vessels. Although usual, these issues could require additional corrective surgery. Once peritoneal dialysis begins, complications related to repeated use of the catheter include peritonitis, which is an infection of the peritoneal cavity. Peritonitis, which can be quite serious, is usually associated with abdominal pain, fevers and cloudy peritoneal dialysis solution. If the infection does not respond to antibiotic treatment, then it may be necessary to remove the catheter.