Introduction:
Dialysis is an artificial method of removing waste from the body in individuals whose one or both kidneys stop functioning. An AV (arteriovenous) fistula is frequently created in end-stage renal disease (ESRD) patients. This is done by creating a passage or access known as a fistula. AV fistula provides access for a more extended period and has fewer associated symptoms.
What Is Dialysis?
Dialysis is a procedure done in people whose kidneys do not function well or have stopped functioning. When kidney failure occurs, the functions of the kidneys are affected. They do not filter blood as they were doing before. Wastes and toxins gets accumulated in the bloodstream as a result of it.
Dialysis is a process done to replace the work of kidneys, including removing waste products and excess fluid accumulated in the bloodstream. The blood from the body is taken out and filtered in a dialysis machine. After purification, it is pushed back into the patient's body in a continuous manner in the process of dialysis. Large tubes are placed into the patient's blood vessels for the blood's removal, cleaning, and return.
For a better and more successful procedure, the patient should possess blood vessels with a large amount of blood flowing through them. Before the dialysis process is initiated, a minor surgical procedure is carried out on the patient so that it becomes easier to access the bloodstream. It can be done in the two following ways:
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Arteriovenous fistula (AV fistula): The surgeon connects an artery and vein in the arm.
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Arteriovenous graft (AV graft): If the artery and vein are too short to connect, the surgeon uses a graft (soft, hollow tube) to connect the artery and vein.
AV fistulas and grafts enlarge the connected artery and vein to make dialysis access easier. They also help flow blood in and out of the body quickly. If dialysis needs to happen quickly, a catheter (thin tube) might be placed into a vein in the neck, chest, or leg for temporary access. Doctors give proper instructions for preventing infections in the fistula or graft.
What Is a Dialysis Fistula?
An AV fistula is a made surgically connection between the artery and a vein by a surgeon (vascular specialist). An AV fistula is generally located in the arm. However, if required, it can be placed in the leg. With an AV fistula, blood flows from the artery into the vein directly, which causes an increase in the blood pressure and amount of blood flowing through the vein. The increased flow and pressure enlarge the veins. The enlarged veins can deliver the necessary blood flow for adequate hemodialysis treatment.
The most recommended vascular access for long-term dialysis is done by AV fistula as they can last for a more extended period when compared to other types of dialysis access, are less susceptible to infections and clotting, and can be relied upon for better performance.
Why Is Dialysis Fistula Preferred?
AV fistula has advantages over others, making the dialysis procedure easier and more feasible. Some of these advantages are:
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It remains functional for a more extended period than other types of vascular access.
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There is no synthetic material used in the body.
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The optimum blood flow needed for adequate dialysis is provided, which might reduce the treatment time.
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Infections are limited or can be managed.
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Less susceptible to clotting than other dialysis access options available.
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It can be made easily in an outpatient procedure under local anesthesia.
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Easy and quick returning to day-to-day activities.
How Is a Dialysis Fistula Created?
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The first step in AV fistula creation is the evaluation of the blood vessels (veins and arteries) to confirm whether they are healthy enough to support the creation of a fistula. The first step in the confirmation is a physical examination of the arms done by a vascular specialist. Then, non-invasive or minimally invasive scans such as ultrasound and possibly an angiogram are done to evaluate the size and depth of the concerned arteries and veins. These tests determine whether the blood vessels can support an AV fistula. These tests are frequently known as "vessel mapping." Once it is ensured that a person can have an AV fistula, the process for the creation of an AV fistula is started.
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First, local anesthesia is administered to the preferred access site to create an AV fistula. A small incision allows access to the selected arteries and veins. A surgical connection is formed between an artery and the vein. This connection allows the blood to flow from the artery into the vein efficiently, which increases the blood flowing through the vein, resulting in the enlargement of the vein and thickening of the walls of the vein. After creating an AV fistula, it takes some weeks, in some cases a month or a longer time, for the fistula to grow until it can be used for hemodialysis treatments.
What Are the Complications Associated With Dialysis Fistula?
Like any other surgical procedure, minor or major, various complications can be seen immediately (within 24 hours) or after a few days or weeks. Some of the complications seen after the creation of AV fistula are:
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Immediate Complications: The immediate possible complications include hematoma (collection of blood seen outside the blood vessel), bleeding, edema (swelling caused due to accumulation of fluid), or loss of thrill due to acute thrombosis (blocked veins or arteries due to clotting of blood).
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Late Complications: The late complications include aneurysm (a bulged, weak area seen in the wall of blood vessels), stricture (narrowing of the urethra), late thrombosis, infection, or neuropathy (seen due to damage to the nerves of the brain or spinal cord).
Conclusion:
A dialysis fistula is a fistula required for the process of dialysis. Dialysis is a process done when a person's kidneys stop functioning or in patients with diseases like end-stage-renal dysfunction (ESRD). In this process, a person's blood is taken out, filtered, and pushed back into the body. For this process to be done successfully, a passage must be made in the body to flow blood in and out efficiently. For this purpose, an AV fistula is created to connect the veins and the arteries. This is usually created in the arm of a person. It has lesser chances of infection. Therefore, it is the most preferred passage for dialysis.
