Dialysis is a vital procedure for many patients suffering from kidney diseases and disorders. When the kidneys can’t function as normal to clean the body of waste products and regulate fluid levels, dialysis machines can carry out those functions instead. However, in order to connect a patient to a dialysis machine, dialysis catheters must be used.
There are multiple types of dialysis access and catheters that may be used, including central venous catheters and arteriovenous grafts. In this guide, we’ll look at descriptions for each of the four forms of dialysis access, covering the pros, cons, and possible complications of each one.
Vascular Access Types for Hemodialysis
Three of the four types of dialysis access are used for hemodialysis. Hemodialysis is a process in which blood is transported out of the body and cleaned by a dialysis machine. The three methods are arteriovenous fistulas, arteriovenous grafts, and central venous catheters.
1. Arteriovenous Fistula (AV Fistula)
An arteriovenous fistula, or AV fistula, is the most preferred method of dialysis access for hemodialysis in the United States and many other countries. In the US alone, over 3 in 5 patients are treated exclusively with the use of AV fistulas, and these devices are considered the best option in the majority of cases and situations.
But what is an AV fistula? In simple terms, it’s a surgical connection created between an artery and a vein. Usually, this connection is formed in a limb, like a patient’s non-dominant arm or one of their legs. The connection allows for fast rates of blood flow through the vessels and into the dialysis machine.
- AV fistulas are one of the most reliable forms of dialysis access.
- They have low risks of infection compared to other methods and devices.
- They also have relatively low risks of clotting.
- An AV fistula can be used for years.
- Needles have to be used to access the AV fistula and carry out hemodialysis.
- Other methods of temporary access may need to be used while the fistula is maturing.
- Maturation can take time.
There aren’t too many risks associated with AV fistulas, but it does take time for the maturation process to occur, during which the fistula matures and heals. This means that the patient may have to wait several months after the initial procedure before the fistula can be used.
When it comes to caring for an AV fistula, patients need to be taught and explained what to do and what warning signs to look out for. Patients should pay close attention to the fistula to make sure it works as intended. They should look out for any swelling, redness, or other physical changes around the site, and listen closely to check that blood is flowing through the fistula.
2. Arteriovenous Graft (AV Graft)
Another method of dialysis access is known as an arteriovenous graft, or AV graft, for short. An AV graft functions in a very similar way to an AV fistula, and it’s a good choice of dialysis access for patients who may be suffering from issues like blocked veins, as well as those who have suffered vein damage, and those with very small or narrow veins.
The AV graft process involves a surgical procedure in which a synthetic tube will be attached to a vein at one end and an artery at the other end. This forms a connection between the vein and the artery which can then be used for dialysis purposes.
- Quick quick to set up and ready to use within a month.
- Relatively easy insertion procedure.
- Placement is an outpatient procedure, which makes things easier for the patient.
- One of the downsides of AV grafts is that they aren’t as long-lasting as fistulas.
- There’s a risk of clotting occurring.
- Needles have to be used to access the graft for hemodialysis.
One of the risks with AV grafts is clotting. It’s possible that blood clots may form around the graft site, which can impede blood flow and negatively impact the dialysis process. Plus, since needles have to be used to access the graft site each time, there’s a risk of infection or injury.
Just like an AV fistula, an AV graft requires constant supervision and care. It’s vital for patients to know what they need to do and look out for to keep their graft in the best possible condition. They should be instructed to look for any redness, swelling, or other problems around the site, as well as listening and feeling for the flow of blood through the tube. Any problems should be reported to a doctor immediately for further assessment.
3. Central Venous Catheter (CVC)
One of the most common pieces of medical equipment used for hemodialysis is a central venous catheter, or CVC. As the name suggests, a CVC is a flexible tube that is inserted into a central vein, usually around the chest or neck region, but also possibly in the groin.
Central venous catheters are Y-shaped tubes. They’re mainly designed for temporary access to the bloodstream, rather than permanent access, and they’re the most commonly-selected method when a patient requires urgent or emergency dialysis treatment, or in cases where AV fistulas and grafts aren’t suitable.
- CVCs are relatively quick and easy to insert into the patient’s body.
- The placement of a CVC is an outpatient procedure, which is usually more convenient for patients.
- CVCs are very useful for immediate, urgent dialysis situations.
- One of the downsides with a CVC is that the patient cannot bathe or swim.
- There is a risk of complications like infections and clots with CVCs.
- There’s also a risk of internal damage to the central veins.
With a CVC, one of the biggest potential complications to worry about is damage to the veins. Improper insertion can lead to damage inside the veins or even punctures of vein walls. There’s also a risk of clots and infections.
Patients with CVCs will need to know how to care for them, with strict instructions to follow to reduce the risks of injuries and infections. The patient should know how to flush the catheter, for example, and should know basic guidelines like not getting it wet, not touching the open end, and keeping sharp items away from the tube.
Body Access for Peritoneal Dialysis
The other form of dialysis access is body access. Body access is used for the process of peritoneal dialysis, in which the blood is actually cleaned while inside the body, using a specialized sterile solution. This method can only be done with one kind of catheter: a peritoneal dialysis or PD catheter.
Peritoneal Dialysis (PD) Catheter
PD catheters are separate from all of the previously-mentioned dialysis access methods and devices, as they are used specifically for peritoneal dialysis, rather than hemodialysis. This type of dialysis involves cleaning the blood inside the body, rather than removing it from the body for external cleaning.
This type of catheter is placed inside the abdomen, with a small part of it left outside the body. It’s the only access device used for peritoneal dialysis, and it doesn’t involve the use of needles. It’s a good choice of dialysis for people with busy lives and schedules, and it’s also recommended for those with specific conditions like inflammatory bowel disease.
- PD catheters are usually inserted as outpatient procedures, meaning that the patient may not need to visit a hospital to have the catheter inserted.
- Needles are not involved in the insertion and usage of PD catheters.
- It’s possible to use PD catheters and have peritoneal dialysis in the comfort of the patient’s home.
- There’s no need for a central venous catheter when using a PD catheter.
- Some activities may not be possible with a PD catheter, like swimming.
- There can be a high risk of clots or infections when using this kind of catheter.
Some of the possible risks and complications with PD catheters include a risk of blood clots around the insertion site, as well as possible infections that may occur if germs pass from the catheter tube into the body. Complications may also occur if the patient tries to bathe or swim while using the catheter.
Due to the high risk of infections with PD catheters, it’s vital to follow a very sterile protocol when handling and working with these devices.