A vascular access surgery makes life-saving haemodialysis treatments possible for patients who need it. Haemodialysis is a treatment used when someone is suffering from a kidney failure that uses a machine to send the patient’s blood through a dialyzer, which is a blood filter outside his/her body.
The access is a surgically created vein, which used to remove and return blood during haemodialysis. The blood goes through a needle and then travels through a tube that takes it to the dialysing machine. Inside the filter, the blood flows through thin fibres that filter out wastes and extra fluid. The dialyzer then returns the filtered blood to the body through a different tube. A vascular access allows for large amounts of blood to flow continuously during haemodialysis treatments to filter as much blood as possible per treatment.
There are two types of vascular access designed for long-term use including the arteriovenous (AV) fistula and the AV graft. A third type of vascular access, called venous catheter, is suitable only for a short-time usage. Doctors generally recommend an AV fistula over the other types of access because it provides good blood flow for dialysis and it lasts longer than other types of access. It is also less likely to get infected or cause blood clots than other types of access. Patients should set up a vascular access well before starting haemodialysis, as AV fistulas and AV grafts both need time to mature in the body before they are ready for use.
An AV fistula is a connection, prepared by a vascular surgeon, between an artery and a vein. Arteries carry blood from the heart to the body, while veins carry blood from the body back to the heart. The surgeon usually places an AV fistula in the upper arm or forearm. It causes extra pressure and extra blood to flow into the vein, making it grow large and strong. An AV fistula requires 2 to 3 months to develop, or mature, before the patient can use it for haemodialysis.
An AV graft is a plastic tube, normally looped, that connects an artery to a vein. 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 and repeated blood clots that can block the flow of blood through the graft. However, a graft can last several years.