DIALYSIS / AV ACCESS

A dialysis or vascular access is a hemodialysis patient’s lifeline, because it makes life-saving hemodialysis treatments possible. Hemodialysis is a treatment for kidney failure that uses a machine to remove waste products from patient’s blood. A dialysis access lets large amounts of blood flow continuously during hemodialysis treatments to filter as much blood as possible per treatment. A dialysis access should be in place weeks or months before the first hemodialysis treatment.

 

Two types of dialysis access designed for long-term use include the arteriovenous (AV) fistula and the AV graft. A third type of dialysis access—the dialysis catheter—is for short-term use.

 

AV Fistula

An AV fistula is a connection, made by a vascular surgeon, of an artery to a vein. Arteries carry blood from the heart to the body, while veins carry blood from the body back to the heart. Vascular surgeons specialize in blood vessel surgery. The surgeon usually places an AV fistula in the forearm or upper arm. An AV fistula causes extra pressure and extra blood to flow into the vein, making it grow large and strong. The larger vein provides easy, reliable access to blood vessels.

Nephrologists & other health care providers recommend an AV fistula over the other types of access because it

  • Provides good blood flow for dialysis.
  • Lasts longer than other types of access.
  • Is less likely to get infected or cause blood clots than other types of access.

 

A vascular surgeon performs AV fistula surgery in an outpatient center or a hospital. This procedure may require an overnight stay in the hospital; however, many patients go home afterward. Majority of time AV fistula can be done under local anesthesia only.

An AV fistula frequently requires 2 to 3 months to develop, or mature, before the patient can use it for hemodialysis.

AV Graft for dialysis

An AV graft is a plastic tube that connects an artery to a vein. A vascular surgeon performs AV graft surgery, much like AV fistula surgery, when suitable veins are not available for AV fistula craetion.

 

A patient can usually use an AV graft 2 to 3 weeks after the surgery. An AV graft is more likely than an AV fistula to have problems with infection and clotting. Repeated blood clots can block the flow of blood through the graft. However, a well-cared-for graft can last several years.

Dialysis Catheter

A dialysis catheter is a tube inserted into a vein in the neck, chest, or leg near the groin, usually only for short-term hemodialysis. If kidney disease has progressed quickly, a patient may not have time for placement of an AV fistula or AV graft before starting hemodialysis treatments and dialysis catheters are used in such kind of patients.

 

Dialysis catheters are not ideal for long-term use. With a dialysis catheter, a patient may develop a blood clot, an infection, or a scarred vein, causing the vein to narrow. However, if a patient needs to start hemodialysis right away, a dialysis catheter will work for several weeks or months until a long-term access surgery and the AV fistula or AV graft has time to mature.

 

If fistula or graft surgery is unsuccessful, then a patient will need a long-term dialysis catheter access. When a patient needs a dialysis catheter for more than 3 weeks, the surgeon will “tunnel” the catheter under the skin, rather than insert it directly into the vein. A tunneled catheter is more comfortable and has fewer problems. Even tunneled catheters, however, may become infected.

 

Dialysis access angioplasty

Sometimes, after using AV fistula or AV graft for many years, it can give problem to the patient. Due to repeated punctures for hemodialysis, AV fistula vein can become narrow and it can give rise to problems during dialysis like

 

  • Less flow during dialysis
  • Pain while doing dialysis
  • Repeated clots in dialysis circuit
  • Swelling of the arm with AV fistula
  • Swelling of face and neck

 

All these patients require proper evaluation of AV fistula or AV graft and if requires it can be treated with angioplasty and with this same dialysis access can be used for many years. If dialysis patients are having any of above symptoms, they should meet vascular surgeon for further assessment and treatment.