Dialysis AV fistulas and grafts are surgical procedures used to create access for hemodialysis in patients with chronic kidney disease. Hemodialysis is a treatment that filters waste and excess fluid from the blood using a machine, and it requires a reliable access point to the bloodstream.
An AV fistula is created by surgically connecting an artery and a vein in the arm, using the patient’s own blood vessels. This creates a large, high-flow access point for hemodialysis. An AV fistula typically takes several weeks to mature and become usable for dialysis, but it is considered the best long-term option because it is durable and has a lower risk of complications.
An AV graft is similar to an AV fistula, but instead of using the patient’s own blood vessels, a synthetic tube is grafted onto the arm to create the access point for hemodialysis. An AV graft is easier to use for dialysis immediately after surgery, but it has a higher risk of complications such as infection and blockage.
In general, AV fistulas are considered the better option because they have a lower risk of complications and are more durable. However, not all patients are able to have an AV fistula, and in some cases an AV graft may be the only option. Your doctor will be able to recommend the best option for you based on your individual circumstances.
AV Fistulas (AVF) –
these are native vessel connections
General consensus is that these are preferred over grafts but 65% of patients are not surgical candidates… Their veins are too small, atherosclerosis,or central venous occlusion.
- AVG DURABILITY = 3 years, intervention extends up to 7 years.
- Signs of fistula failure = arm swelling, elevated central venous pressure at dialysis, decreased thrill
- Forearm = Radiocephalic (Brescia-Cemino) – 70%
- Elbow/Arm = Brachiocephalic or brachiobasilic – 30%
- Better long-term patency
- Lower rate of thrombosis o Lower rate of infection
- Fistula takes, on average, 10 weeks to reach maturation for use.
- Stenosis of the outflow vein (just beyond the anastomosis) B A Radiocephalic AVF with minor stenosis at anastomosis
- (A) and major stenosis 2 cm into the outflow vein (B). AV Grafts
(AVG) – these are artificial conduits Most common graft is a 6-mm PTFE (synthetic) graft
AVG DURABILITY = 1-2 years
intervention extends up to 3-5 years
SITES o Upper extremity: Brachiobasilic, Radiocephliac, Axillary-axillary, Axillary-contralateral axillary (“necklace”), etc. o Lower extremity: Femoral-saphenous, femoral-femoral
BENEFITS o Ready for use sooner, in 4-6 weeks o Can be placed in any number of locations
PROBLEMS o **Stenosis at the venous anastomosis – 90% of cases secondary to intimal hyperplasia. o Less common stenosis occur inside the graft and in the outflow vein. o Thrombosis – o Infection – this is a contraindication to endovascular intervention.
Treatment of graft thrombosis generally involves placing an angiocath and slowly infusing 2 mg tPA and waiting. There are also mechanical methods of thrombectomy.