What is an Arteriovenous Fistulogram?
An arteriovenous fistulogram is a minimally invasive special X-ray procedure to look for abnormalities in the arteriovenous (AV) fistula or AV graft (dialysis access) that may be impeding or causing problems with your dialysis treatment.
Hemodialysis or dialysis is a procedure performed to manage patients suffering from kidney failure. A dialysis machine takes over the function of the diseased kidneys by filtering the blood of waste products. During dialysis, you will be attached to a machine called a dialyzer through a thin tube. Your blood is then drawn into the machine for filtration through a needle inserted in your arm. The blood is circulated in the dialyzer and the filtered blood is returned back to the body through another tube. This is usually performed three times a week, so it requires easy access to the bloodstream each time. Vascular access is a surgically created large vein that provides easy access to the bloodstream and can withstand repeated needle insertions.
There are two types of vascular accesses created for long-term dialysis use:
- Arteriovenous fistula: An abnormal connection surgically created between an artery and a vein. This allows the blood vessel to grow larger and have thicker walls, facilitating repeated puncturing. It provides good blood flow and is preferred for its lower rate of infection and clot formation, and greater longevity.
- Arteriovenous graft: A thin, flexible, synthetic tube (graft) is used to attach one end of an artery with another end of a vein. The graft is punctured to draw blood.
Indications for Arteriovenous Fistulogram
Arteriovenous fistulogram is indicated when your dialysis access points, AV fistula or AV graft, is causing problems, such as:
- Blocked veins or arteries (occlusion)
- Abnormal narrowing (stenosis)
- Areas of abnormal enlargement (pseudoaneurysm)
- Reduced blood flow to your access
- Untoward symptoms as a result of access
- Access problems affecting your dialysis treatment
Preparation for Arteriovenous Fistulogram
Preparation for arteriovenous fistulogram procedure may involve the following steps:
- Blood tests to check for normal kidney function, to ensure that your blood clots normally, and to obtain other information.
- You need to inform your physician if you have allergies to certain medications, sedatives, or contrast dye.
- You should also inform your doctor of any medications or supplements you are taking or any conditions you have such as blood disorders, heart or lung disease.
- You may be asked to stop taking blood-thinners, anti-inflammatories, aspirin, or other supplements for a specific period.
- You should not consume solids or liquids at least 6 hours prior to the procedure.
- You should arrange for someone to drive you home after the procedure.
- A signed informed consent form will be obtained from you after the procedure has been explained.
Procedure for Arteriovenous Fistulogram
Arteriovenous Fistulogram is a safe and common procedure and takes less than an hour. In general, the procedure involves the following steps:
- You will be brought into a procedure room and asked to lie on an X-ray table with machines all around you.
- You will be connected to a monitor that provides details about your heart rate, blood pressure, and oxygen level.
- You will be covered with a sterile drape from your shoulders to your feet.
- Sedatives and pain medications are given to keep you relaxed throughout the procedure.
- The fistula or graft arm is placed on a small table and the access site is thoroughly cleaned.
- Your physician will inject some medication to numb the area that is checked on your graft or fistula.
- Once the skin is numb, a small catheter (thin tube) is inserted into your access (graft or fistula).
- Your physician then injects contrast dye into the catheter tube and X-rays are taken in order to view the condition of the graft or fistula.
- These x-ray images will enable your physician to identify what is causing problems in your dialysis access.
- If your graft or fistula has stopped working, your physician may administer blood thinners into the tube.
- If abnormal narrowing is observed, it is typically treated by stretching the narrowed region open with balloon inflation (angioplasty). Sometimes, a stent may be used to help keep the narrowed section open.
- Once the procedure is complete, the catheter tube is removed and pressure is applied over the puncture site to stop bleeding.
- You may need a couple of stitches over the puncture site.
Post-Procedure Care and Recovery
Following the procedure, you will be transferred to the recovery room where you will be observed for a couple of hours. During this period, a nurse will monitor your vital signs, condition, and ensure that the bleeding has stopped. Once you are found to be stable, you will be discharged to go home or proceed to the dialysis centre for treatment. You will need somebody to drive you back as you are not allowed to drive yourself. You may drive the following day. You may resume your normal activities 24 hours after your procedure.
Benefits of Arteriovenous Fistulogram
Some of the benefits of arteriovenous fistulogram include:
- X-ray images offer sufficient information that can help prevent more invasive procedures
- X-rays typically do not cause any side effects
- The test offers real-time images for immediate evaluation and decision making
- Offers precise information that can assist your physician to develop an ideal treatment plan for your condition
Risks and Complications
Arteriovenous fistulogram is a very safe procedure, but some risks and complications may occur, such as:
- Bruising at the site of the needle puncture
- Swelling or redness around the puncture site