Last month, I talked about why a patient might need to undergo arteriovenous fistula surgery. This month, let’s take a look at how AV fistulas and grafts are formed.
Before AV fistula surgery, the surgeon may perform a vessel mapping test. Vessel mapping uses Doppler ultrasound to evaluate blood vessels that the surgeon may use to make the AV fistula. Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. A specially trained technician performs the procedure in a healthcare provider’s office, an outpatient center, or a hospital. A radiologist interprets the images. The patient does not need anesthesia for this procedure. A Doppler ultrasound shows how much and how quickly blood flows through arteries and veins so the surgeon can select the best blood vessels to use.
A surgeon performs AV fistula surgery in an outpatient center or a hospital. The vascular access procedure may require an overnight stay in the hospital; however, many patients go home afterward. A healthcare provider uses local anesthesia to numb the area where the surgeon creates the AV fistula.
An AV fistula frequently requires two to three months to develop, or mature, before the patient can use it for hemodialysis. If an AV fistula fails to mature after surgery, the surgeon must repeat the procedure.
At the start of a hemodialysis session, a health care provider or the patient inserts two needles into the vascular access. One needle carries blood from the body to the dialyzer. The other carries filtered blood back to the body. To tell the needles apart, the needle that carries blood away from the body is called the arterial needle. The needle that carries blood back to the body is called the venous needle. Some patients prefer to insert their own needles into the vascular access, which requires training to learn how to prevent infection and protect the vascular access. No matter who inserts the needles, the patient should know how to take care of the needle insertion area to prevent infection.
If an AV fistula does not mature, an AV graft is the second choice for long-lasting vascular access.
What is an arteriovenous graft?
An AV graft is a looped, plastic tube that connects an artery to a vein. A vascular surgeon performs AV graft surgery, much like AV fistula surgery, in an outpatient center or a hospital. As with AV fistula surgery, the patient may need to stay overnight in the hospital, although many patients can go home after the procedure. A health care provider uses local anesthesia to numb the area where the surgeon creates the AV graft.
A patient can usually use an AV graft two to three 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.
For more information go to kidney.org/atoz/content/hemodialysis
