Why can't a vein be used alone for dialysis?

From the Guidelines

A vein cannot be used alone for dialysis because it lacks the necessary strength and durability to withstand the high blood flow rates and repeated needle insertions required for effective hemodialysis, as evidenced by the most recent guidelines and studies 1.

Key Considerations

• Veins have thin walls and low blood pressure, making them prone to collapse under negative pressure and unable to handle high flow rates of 300-400 mL/min required for hemodialysis.
• Repeated needle insertions needed for dialysis sessions can cause damage to the vein, leading to stenosis or narrowing, which further compromises blood flow.
• The creation of an arteriovenous (AV) fistula or graft, which connects an artery to a vein, allows the vein to "arterialize" and become stronger, enabling it to handle the high blood flow rates and repeated access needed for dialysis.

Clinical Implications

• The use of AV fistulas or grafts is recommended for dialysis access due to their superior patency rates and lower complication rates compared to other access types, as supported by recent guidelines 1.
• A patient-centered approach to vascular access planning is essential, considering the individual's needs, dialysis access eligibility, and future access requirements, as emphasized in the 2019 KDOQI guidelines 1.
• Regular monitoring and surveillance of vascular access are crucial to detect potential complications early and prevent access failure, as highlighted in the ACR Appropriateness Criteria for dialysis fistula malfunction 1.

From the Research

Reasons for Not Using a Vein Alone for Dialysis

• A vein alone cannot be used for dialysis due to the high risk of complications such as thrombosis, infections, and stenosis 2, 3.
• The use of a vein alone for dialysis is associated with higher morbidity and mortality compared to other types of vascular access, such as arteriovenous fistulas (AVFs) or grafts 3, 4.
• AVFs are considered the gold standard for vascular access in hemodialysis patients, as they provide a high blood flow rate and are associated with a lower risk of complications compared to veins alone 5, 6.
• However, in some cases, a vein may be used as a last resort for dialysis, such as when an AVF is not possible or has failed to mature 4, 6.

Complications Associated with Vein Use for Dialysis

• Thrombosis: the formation of blood clots in the vein, which can lead to occlusion of the vein and failure of dialysis 2, 3.
• Infections: bacterial infections can occur at the site of the vein access, leading to sepsis and other complications 2, 4.
• Stenosis: narrowing of the vein, which can lead to reduced blood flow and failure of dialysis 3, 4.
• Central venous stenosis: narrowing of the central veins, which can lead to swelling and pain in the arm 4.

Alternative Options for Dialysis

• Arteriovenous fistulas (AVFs): considered the gold standard for vascular access in hemodialysis patients, as they provide a high blood flow rate and are associated with a lower risk of complications compared to veins alone 5, 6.
• Arteriovenous grafts (AVGs): may be used as an alternative to AVFs, but are associated with a higher risk of complications compared to AVFs 6.
• Central venous catheters (CVCs): may be used as a last resort for dialysis, but are associated with a higher risk of complications compared to AVFs or AVGs 2, 3, 4.