Overview
When patients have chronic kidney disease or experience sudden kidney failure, there is a risk that their kidneys may permanently stop working. Consequently, most of these patients often require haemodialysis multiple times a week as replacement therapy. Haemodialysis is a treatment in which a machine is used to filter out waste and excessive fluids from blood flow and restore proper electrolyte balance. An arteriovenous (AV) fistula, or alternatively a graft is needed to perform haemodialysis.
A dialysis fistula is a direct connection between an artery and a vein in the arm, while a dialysis graft is created using a small synthetic tube under the skin, serving a similar purpose. Scarring or blood clots can narrow or block the fistula or graft or the blood vessels in the arm or chest.
Symptoms
If you have an AV fistula or AV graft malfunction, your doctor may notice symptoms when clinically examining the fistula or graft, such as a throbbing sensation in the area or swelling of the arm caused by fluid retention.
Modern dialysis machines can identify some problems resulting from malfunctions, such as insufficient blood flow caused by a narrowing of the supplying artery (stenosis), or blood exerting abnormally high levels of pressure on vein walls as a result of the narrowing of a big vein in the chest.
Diagnosis
After the clinical examination, usually the doctor will prescribe a Colour-Doppler Ultrasound to investigate the cause of the malfunction. Sometimes other imaging methodes such as CT or MRI may be needed.
Treatment
When there are issues with dialysis, it may be necessary to do a procedure called a fistulogram to fix it.
After numbing your skin, your clinician injects contrast dye into the fistula or graft to check for any issues. They will then, with the help of x-rays for guidance, thread thin wires and tubes into the arm’s blood vessels. To open the blood vessels, they might use small balloons, tools, or clot-dissolving medicine.
Medication to prevent the formation of blood clots may be needed.