When someone need to have regular haemodialysis, our first question is what can use as his vascular access for dialysis. Usually our first choice is AV fistula. However often have to try for AV graft (Arterio Venous Graft) too. Usually in US population, 15% patients undergoing hemodialysis use the AV graft instead of any other method. Although it is not the most superior method as permanent vascular access, we have to select this as the first choice in some set of patients.
What is AV Graft?
AV graft or Arterio Venous Graft means an artificial connection between arterial line and the venous line. We use an artificial hollow material to create the surgical connection between two vessels. Usually this connection is created in elbow pit.
When to use the AV graft?
As we mentioned earlier, Av graft is not the most effective method of permanent vascular access for haemodialysis. However in some special situations, it is the first choice as a vascular access for dialysis.
- Patient with inadequate venous access.
- Patient who need an access soon.
Advantages of AV graft
Can use for patient need urgent regular haemodialysis
When you use an AV fistula for dialysis, you may have to wait for another 3 -6 month to maturity of the fistula site.However Arterio venous graft do not take that much of time to initiation of the dialysis. Usually we can start the haemodialysis after 1 month of the surgery. This is due to the fast maturity of the graft site.
Can use in patients with small blood vessels
Formation of AV fistula is very difficult surgery. Especially it is difficult procedure in wrist area. This is because of the absence of the large blood vessels in this area. However Arterio Venous graft can be used even in patients with vascular issues.
Need only the local anesthesia
This surgery is done under local anesthesia. In addition it is performed as a day surgery. Therefore you do not need long hospital stay.
Disadvantages of Arterio Venous Graft (AV Graft)
- Insertion of artificial material to body
We use synthetic material to connect two blood vessels together. Therefore we have to insert this synthetic material to the fistula site. - Risk of closure
Although the AV fistula is often last a long time, there is a high chance of AV graft to get blocked by frequent blood clots. - Risk of infections
As we have placed a synthetic material in our body, it is often tend to get infected. Therefore careful handling is necessary.
How to prepare for AV graft
When you are diagnosed as having Chronic Kidney Disease (CKD), your nephrologist would discuss about the future treatment options with you. You need hemodialysis only if you become a patient with End Stage Kidney Disease (ESKD). However there may be some other instance you need a dialysis in an acute set up.
When your condition is getting worse you have to select a kind of option from Kidney transplant, regular haemodialysis, CAPD or no treatments. If you select to dialyze for long time, you need to select your vascular access for dialysis. As we already have discussed Arterio Venous Fistula (AV Fistula) is the most commonly used vascular access. However there are options like Arterio Venous Graft (AV Graft) and Permanent catheter. Your vascular surgeon will decide your mode of vascular access depending on your conditions.
What is better option between hemodialysis and peritoneal dialysis?
This is probably will do after a proper vascular mapping and physical assessment.
Then you will give a date for the surgery probably as outpatient setting.
After 2 – 4 weeks of surgery your vascular surgeon will allow you to puncture the fistula site.
How to handle the AV graft during haemodialysis
Whenever an AV graft or AV fistula is created it should be handle in a proper way. Unless the lifespan of the vascular access get reduced. Then we have to reconstruct the vascular access or we have to recreate a vascular access.
You can apply some local anesthetic medication like lignocaine to reduce the pain during puncturing of the AV graft. But usage of subcutaneous lignocaine can increase the site of punctures.
You should handle the AV fistula in a way that minimum infections would be entered. Proper hand washing and disinfectants may be helpful to reduce the number of infections. Povidone Iodine solution can be used to clear the skin around the puncture site of the fistula.
You can use the same way as the puncture of the AV fistula for dialysis. That is puncturing of two sites of vein, one close to the arterial connection and other one way from the arterial connection.
You will use 16G AV Fistula needle for the procedure.
At the end of the dialysis session, you have to stop the bleeding with moderate pressure around the puncture site.
Proper use of heparin during dialysis will reduce the unnecessary bleeding will preventing the unnecessary clots.
Related articles
- Michael Allon MD, Charmaine E. Lok MD, MSc, FRCPC, in Handbook of Dialysis Therapy (Fifth Edition), 2017.
https://www.sciencedirect.com/science/article/pii/B9780323391542000059 - Michael Allon, M.D., University of Alabama at Birmingham, Vascular Access for Hemodialysis, UCSF Department of surgery, 2014.
https://surgery.ucsf.edu/conditions–procedures/vascular-access-for-hemodialysis.aspx