There are different types of vascular access
Temporary dialysis catheter
This is a Y shaped tube. One end is placed inside a large central vein and the other end has two lumens which are used to connect to the dialyzer. Blood flows out of the body through one lumen, circulates through the dialysis machine, and flows back into the access through the other lumen. They can be done on the same day and utilised immediately. But the main drawback of catheter is the risk of infection. If not infected, it can be used for up to 8 weeks.
Tunnelled dialysis catheter (Permacath)
This is almost like a temporary dialysis catheter in that its end is inside a large central vein but then the other end is tunnelled under the skin and opens upon the chest wall. A tunnelled catheter is done on the same day and can be utilised immediately. Due to tunnelling and presence of a cuff, infections are less common with tunnelled catheters. If not infected, they can be used for up to a year.
An arteriovenous fistula is created by making a surgical connection between one of your arteries and one of your veins. Most of the time, a fistula is created in your non-dominant arm, but it can also be placed in your leg if the arteries and veins in your arm are not large enough or healthy.
The AV fistula creation procedure is considered minor surgery and is typically performed on an outpatient basis. The entire procedure usually takes about one hour to complete.
After you’ve been mildly sedated, your vascular specialist will use local anesthesia to numb the area in your arm or leg where the fistula will be created. Next, a small incision will be made in order to locate the vein and artery that will be used to create the fistula. Once they are located, the vein will be connected to the artery and the skin incision will be sutured closed.
AV fistulas need time to heal and mature completely before they can be used as an access.
If your veins are healthy and you don’t need immediate dialysis, an arteriovenous fistula will likely be your best option for a dialysis access. Even if you need immediate dialysis, your doctor may still suggest that you consider an AV fistula created for long-term treatment.
To determine whether your veins are healthy enough and large enough for an AV fistula, you will need to have a procedure, known as vessel mapping, performed. This can be done using an ultrasound machine or by injecting contrast dye into your veins while under fluoroscopy (a type of x-ray) so an image, or map of your veins, can be obtained.
An arteriovenous fistula requires daily inspection and care. You need to clean it every day with soap and water, and you’ll want to avoid sleeping on it. You need to look, listen and feel for signs that your AV fistula is functioning properly.
Look – Look at your access to check for signs of infection – swelling, redness, warmth and drainage are all signs to watch for. Also note if there are any changes to the skin, such as bleeding, bulging or peeling.
Listen – Put your ear to your arm (or leg) and listen for the sound of blood flowing through your fistula.
Feel – Put your hand on your access to feel the “thrill.” Any change in the feel of the vibration, or an absence of vibration is cause for concern. If there is no vibration or thrill you should notify your doctor immediately.
Your AV fistula will allow more blood to flow through your vein at a faster rate and therefore an increase in the pressure within the vein. This increased venous pressure stretches and strengthens the vein, allowing more blood to flow back and forth from your vein to the dialyzer in a shorter amount of time.
There are many advantages to an AV fistula, including:
Like any of your options for dialysis access, an arteriovenous fistula is not without their disadvantages. But these drawbacks are fairly minor compared to the problems often associated with other access types, such as a central venous catheter (CVC).iv The main disadvantages of having an AV fistula can be:
Needles are required to access the AV fistula for dialysis.