The Access for Dialysis

The Access for Dialysis

The fistula or graft provides the lifeline for the kidney failure patient to receive hemodialysis. The vascular access connects an artery to a vein and over time the vein will enlarge and become “arterialized”. If the patient has poor veins, it may require placing a synthetic vessel know as a graft to connect between the artery and the vein. If a fistula is created, it can take three to six months before this access can be used for dialysis. A graft can be used much sooner, usually between three to six weeks. Fistulas can last for many years but they can develop problems over time. The flow through the fistula will be between 600 to over 2000 cc per minute. This high flow can lead to strictures and narrowing of the fistula reducing the flow and causing excessive bleeding when the needles are removed at the end of the dialysis treatment. When this occurs, the patient will need to be seen in an access center where a fistulagram will be performed to identify the source of the bleeding or reduced blood flow. When found, angioplasty and/or stenting of the access will restore the flow and improve the bleeding. If this is done promptly, it avoids clotting of the access and any interruption of the dialysis treatments. Grafts that are used for those having poor vein structures can be used earlier but they have a limited lifespan of usually 5 years. They are more likely to clot and have a greater propensity to get infected so a fistula is a preferred vascular access.

Placement of a fistula should be timed to occur at a minimum three months before the patient needs dialysis. As a general rule, the nephrologist should begin discussing with the patient the options for the patient and that he or she will likely require dialysis. This discussion should occur at about 30% kidney function. At 20% kidney function, the vascular access should be created. Even if the patient is choosing peritoneal dialysis which would not require a vascular access, many nephrologists still prefer to create a fistula. Peritoneal dialysis may not be effective and that will only be discovered after they start dialysis. Moreover, even when effective, over time the peritoneal membrane may fail or the patient will develop peritonitis requiring a conversion to hemodialysis.  

These discussions and interventions are life changing for the patient. From my career spanning 43 years, I have appreciated how difficult this can be for the patient and their families. To help educate the public about the impact for the patient, I wrote a medical thriller, “The Perfect Match”. Written much in the style of John Grishan’s novels, it is an entertaining fictional story but the reader will learn what the patient goes through when learning that they need to start dialysis.

Dennis Ross MD, FACP, FASN