Vascular Access for Haemodialysis
Your kidneys function as filters in your body, removing toxins and adjusting fluid and nutrient concentrations. They keep what your body needs in your blood while also producing urine, which contains what you don’t.
What are the options for kidney failure treatment?
Dialysis and kidney transplantation are the two treatments for kidney failure.
Dialysis is a procedure that clears your blood of wastes and excess water.
Kidney transplantation is a surgery in which a surgeon implants a new kidney into your body. A new kidney will replace your failing kidneys.
What is dialysis?
Dialysis acts as a “substitute kidney,” filtering your blood and removing toxins. If your kidneys fail, dialysis is a life-saving method of cleaning your blood to remove waste from your body. There are two types of dialysis; haemodialysis and peritoneal dialysis. Each has advantages and disadvantages, and you and your health professional can decide which is best for you.
Haemodialysis involves the use of a machine to filter your blood. Haemodialysis is conducted through vascular access, connecting your blood vessels to the haemodialysis machine.
Peritoneal dialysis involves inserting a catheter (tube) and a special fluid into the abdomen to filter waste.
What is Haemodialysis Vascular Access?
Dialysis staff must have access to your bloodstream to provide regular haemodialysis treatment. It is known as ‘Vascular Access’, and it will necessitate surgery or a procedure.
The three most prevalent types of vascular access are:
AVF (Arteriovenous Fistula) – Also known as your fistula
The arteriovenous graft (AVG) is also known as your graft
The Central Venous Catheter (CVC) is often known as your line
Peritoneal Dialysis
AVF (Arteriovenous Fistula)
What is an arteriovenous fistula?
As the name indicates, an AV fistula connects an artery and a vein beneath the skin. The pressure inside the vein increases as the artery and vein are joined, making the vein stronger and more prominent. Then, your dialysis nurse can insert two needles into the vein after getting strong. One needle removes blood from the body and returns it to the machine, while the second needle restores blood to the body. The procedure is usually a day-case procedure that takes about two hours to complete. For this procedure, doctors typically use your non-dominant arm (the one you don’t use to write with) under local anaesthesia or a nerve block. You may also require intravenous sedation, which can help you sleep or rest.
When is it done?
The optimal time to make a fistula is before you need dialysis. You do not need to start dialysis because you have a fistula. Making one before starting dialysis gives the fistula time to mature and be ready if needed.
What are the advantages of getting a fistula?
Fewer complications risk compare to the line in the neck. Infection rates are low. It utilised your natural arteries and veins rather than artificial materials.
Where will the scar appear?
The surgeon, in most cases, makes the incision at the wrist or the elbow crease. Occasionally, you might have a long scar on the inside of your arm or in your axilla.
Will my arm be able to move normally?
After a successful procedure, you should be able to resume your normal activities and move your arm normally. Your surgeon will instruct you to keep the surgical site dry for a few days following the procedure. Following that, you will be able to take a bath, shower, or even go swimming.
What should you do to help your fistula?
Squeezing a rubber ball and other gentle exercises will encourage blood flow and aid in developing your fistula.
Touching the fistula can result in a ‘buzzing’ sensation. So check for it every day, and if it weakens or stops, please get in touch with the dialysis unit.
Avoid wearing tight clothing or a wristwatch if your fistula is on your wrist.
Please do not allow anyone except the dialysis team to take blood from your fistula arm or insert a drip into it. Likewise, no one should take your blood pressure on your fistula arm.
Avoid sleeping on your fistula arm.
Is there any risk associated with an AV fistula?
The AV fistula is the best way for dialysis patients to receive dialysis because it is a long-term solution with a low risk of infection. Any surgery, however, carries its own set of risks.
Failure: unfortunately, not all fistulas work, and you may need another procedure or surgery.
Bleeding: is possible, but it is uncommon. If you are at home and see bleeding from the surgical wound, apply local compression over the bleeding site and contact an emergency service.
Infection: The wound site starts to be red, hot and painful.
Steal Syndrome: If your fistula works “too well”, too much blood may flow through it and not enough towards your hand, resulting in steal syndrome. As a result, you may have a pricking sensation in your fingertips, cold fingers, and soreness.
Nerve Injury: Making a fistula can damage the nerves that travel near the vessels. You may have numbness in a specific skin area of your arm.
Arteriovenous graft (AVG)
The graft is similar to a fistula. But, in this procedure, the surgeon uses a synthetic tube to connect the artery to the vein. Grafts are helpful when a haemodialysis patient has small or poor veins that will not develop properly into a fistula.
What is the difference between AV graft and AV fistula?
Advantages of the AV graft:
- It is a more rapid approach than the AV fistula, which requires 4-8 weeks for maturation.
- The initial failure rate is low.
- Drawbacks of having a graft:
- Synthetic materials raise the greater risk of blood clots, aneurysms, and infections.
- Grafts do not always persist as long as fistulas.
The Central Venous Catheter (CVC)
What is the meaning of a central venous catheter CVC (Line)?
The CVC is a soft, flexible artificial tube inserted into a large vein, most commonly in your chest and sometimes in the groin. There are two lumens or ports in the CVC. During haemodialysis, one lumen takes blood from your body for filtration. The blood then returns to your body through the other lumen.
What are the different types of CVC used in dialysis?
- Tunnelled (permanent)
- Tunnelled CVCs are typically inserted under x-ray guidance and are operable for a considerable duration.
- Non-Tunnelled (Temporary)
- Non-tunnelled CVCs are effective in an emergency for a short duration. Your specialist typically places them in the neck or groin.
What are the potential advantages of using a central venous catheter?
CVC is ready to use immediately if necessary and can be helpful in emergency dialysis. It can be used for patients who cannot have an AVF/AVG.
What are the risks of having a central venous catheter?
Complications During insertion such as bleeding from central veins, injury to the lung or main arteries.
Fibrin sheath production around the line causes gradual narrowing, inhibiting good dialysis flows and blood clearing.
It can cause a narrowing of the central veins, preventing the formation of future fistulas.
There is a high risk of clot formation in the central veins and blood infection.
