What are the principal surgically created arteriovenous fistulas used for hemodialysis?

Types of Arteriovenous Fistulas for Hemodialysis

Primary AV Fistula Types (Preferred Access)

The wrist (radial-cephalic) arteriovenous fistula is the first-choice vascular access for hemodialysis, followed by the elbow (brachial-cephalic) fistula as second choice. 1, 2

1. Radial-Cephalic (Wrist) Fistula - First Choice

This connects the radial artery to the cephalic vein at the wrist level. 1

Advantages:

• Simple surgical creation 1
• Preserves proximal vessels for future access sites 1
• Low complication rates including minimal vascular steal risk 1
• Low thrombosis and infection rates once mature 1
• Excellent long-term patency 1

Disadvantages:

• Lower blood flow compared to more proximal fistulas 1
• If adequate flow (>500-600 mL/min) is not achieved within 4 months, another access type must be established 1

2. Brachial-Cephalic (Elbow) Fistula - Second Choice

This connects the brachial artery to the cephalic vein at the antecubital fossa, with anastomosis diameter of 5-10 mm. 1, 2

Advantages:

• Higher blood flow than wrist fistula 1, 2
• Easy cannulation with good surface area 1, 2
• Cosmetically favorable as the cephalic vein is easily covered 1
• Excellent patency once established 2

Disadvantages:

• Slightly more technically demanding surgically than radial-cephalic 1
• May cause more arm swelling 1, 2
• Higher risk of steal syndrome compared to wrist fistula 2

Alternative Access Options (When Primary Fistulas Cannot Be Created)

3. Transposed Brachial-Basilic Vein Fistula

This uses the basilic vein transposed superficially after connecting to the brachial artery. 1, 3

Key Characteristics:

• Requires staged procedures in most cases (77.6% in one series), with second-stage transposition 4-6 weeks after initial AVF creation 3
• Single-stage creation possible when brachial vein diameter ≥6 mm 3
• Cumulative patency of 92.4% at 24 months 3
• More technically demanding with tedious vein harvesting 3
• Useful when basilic vein is the only remaining option 3, 4

4. Brachial Vein Transposition Fistula

Reserved for patients with difficult access extremities where all superficial veins are obliterated. 3

Characteristics:

• Requires staged procedures in most patients 3
• Primary patency 52.0% at 12 months, but cumulative patency 92.4% at 24 months 3
• Most patients require intervention for maturation or maintenance 3

5. Synthetic (PTFE) Arteriovenous Graft

Polytetrafluoroethylene (PTFE) grafts are the preferred synthetic material when autogenous fistulas cannot be established. 1

Advantages:

• Large surface area for cannulation 1
• Technically easy to cannulate 1
• Short maturation time (minimum 14 days, though longer is preferred) 1
• Multiple insertion sites available 1
• Various configurations (straight, looped, curved) 1

Disadvantages:

• Higher infection rates than native fistulas 1
• Lower patency rates 1
• Expected lifespan 3-5 years 1
• Higher complication rates including stenosis 1

Critical Selection Algorithm

Follow this hierarchical approach: 1, 2

1. First attempt: Radial-cephalic (wrist) fistula if arterial diameter ≥2.0 mm and venous diameter ≥2.5 mm 2, 5
2. Second attempt: Brachial-cephalic (elbow) fistula if wrist vessels inadequate or wrist fistula fails 1, 2
3. Third option: Transposed brachial-basilic vein fistula 1
4. Fourth option: Synthetic PTFE graft 1
5. Last resort: Tunneled cuffed central venous catheter (strongly discouraged as permanent access) 1

Essential Preoperative Requirements

All patients must undergo duplex ultrasound vascular mapping before fistula creation. 2, 6

Minimum vessel criteria for success: 2, 5

• Arterial diameter >4.0 mm associated with fewer failures 5
• Arterial diameter <2.0 mm has 95.9% specificity for immediate failure 5
• Venous diameter ≥2.5 mm minimum 2

Common Pitfalls to Avoid

• Never create a brachial-cephalic fistula first without attempting distal forearm access - this eliminates future proximal options for younger patients 2
• Never place ipsilateral central venous catheters while fistula is maturing - causes central venous stenosis 2, 6
• Never use subclavian vein access - high risk of central stenosis that compromises fistula function 2, 6
• Never proceed without vascular mapping - leads to high failure rates 2
• Never cannulate before 1 month minimum (ideally 3-4 months) - premature use causes permanent fistula loss 7, 6

Maturation Criteria Before Use

A fistula is ready for use when: 1, 7

• Minimum 1 month has elapsed (preferably 3-4 months) 7
• Vein diameter ≥4-6 mm 1, 7
• Blood flow >500-600 mL/min 1, 7
• Depth <6 mm from skin surface 1
• Continuous palpable thrill along entire outflow vein 7