There are different types of vascular access
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.
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.
AV fistula is the best preferred type of vascular access for most patients. It requires a surgical procedure that creates a direct connection between an artery and a vein. This is often done in the lower portion of the nondominant arm but can be done in the upper arm as well.
Regardless of its location or how it is created, the access is located under the skin. During dialysis, two needles are inserted into the access. Blood flows out of the body through one needle, circulates through the dialysis machine, and flows back into the access through the other needle.
Since it is created using arteries and veins, and doesn’t have any foreign body, there is minimal risk of infection and they can be used for quite a long time. It takes 4 to 8 weeks for an AVF to become mature to be useful for dialysis. Hence, it is best prepared when a patient reaches stage 4 CKD.