What are the indications and procedure for creating an arteriovenous fistula (AVF) in the brachiocephalic (BC) region for hemodialysis?

Brachiocephalic Arteriovenous Fistula: Indications and Procedure

A brachiocephalic (elbow) arteriovenous fistula is the second-choice vascular access for hemodialysis, indicated when a wrist radiocephalic fistula cannot be created or has failed, and should be prioritized over synthetic grafts and transposed basilic vein fistulas. 1

Indications for Brachiocephalic AVF

Primary Indications

• Inadequate distal forearm vessels for radiocephalic fistula creation, specifically when preoperative arterial diameter is less than 2.0 mm or venous diameter is less than 2.5 mm 1
• Failed or inadequate wrist fistula that does not achieve sufficient blood flow within 4 months to support hemodialysis prescription 1
• Anticipated long duration on hemodialysis (>1 year) when forearm options are exhausted 1

Patient-Specific Considerations

• Elderly, diabetic, or hypertensive patients may benefit from brachiocephalic fistula as primary access, though forearm attempts should still be considered first to preserve proximal vessels 2
• Patients requiring rapid maturation with high likelihood of unassisted maturation and anticipated limited duration (<1 year) on hemodialysis 1

Hierarchical Approach to Access Selection

The KDOQI guidelines establish a clear order of preference: 1

1. First choice: Wrist (radiocephalic) primary AVF
2. Second choice: Elbow (brachiocephalic) primary AVF
3. Third choice: Synthetic arteriovenous graft (PTFE) or transposed brachial basilic vein fistula

This hierarchy prioritizes vessel preservation for future access needs, particularly important given increasing life expectancy of hemodialysis patients 2

Preoperative Evaluation Requirements

Vascular Mapping

Preoperative duplex ultrasound vascular mapping is essential and should assess: 1

• Arterial evaluation: Pulse examination, differential blood pressure measurement, palmar arch patency (Allen test), arterial diameter ≥2.0 mm, presence of arterial calcification 1
• Venous evaluation: Cephalic vein luminal diameter ≥2.5 mm, continuity with proximal central veins, absence of central venous obstruction 1
• Central vein assessment: Duplex ultrasound (97% specificity, 81% sensitivity for central vein occlusion), venography, or MRA if prior central venous catheterization 1

Clinical Assessment

Physical examination must document: 1

• Character of peripheral pulses with hand-held Doppler when indicated
• Bilateral upper extremity blood pressures to determine arterial suitability
• Evidence of arm edema or size discrepancy suggesting venous outflow problems
• Collateral veins indicating venous obstruction
• History of previous central/peripheral venous catheterization, arm/chest/neck surgery or trauma
• Cardiovascular status including heart failure assessment

Surgical Procedure

Anatomic Configuration

The brachiocephalic AVF connects the brachial artery to the cephalic vein at the antecubital fossa. 1 The anastomosis is typically created in the elbow region where the cephalic vein courses superficially in the upper arm.

Anastomosis Size

Conventional teaching recommends 7-10 mm anastomosis diameter, though recent evidence suggests 5-6 mm anastomoses may provide adequate flow while minimizing steal syndrome risk (0% vs 9% steal syndrome with smaller anastomoses). 3 However, smaller anastomoses showed lower primary patency at 1 year (46.9% vs 67.9%) despite similar functional patency (82.2% vs 87.7%). 3

Technical Considerations

The procedure is slightly more technically demanding than radiocephalic fistula creation but less invasive than brachiobasilic transposition, making it the preferred choice when both cephalic and basilic veins are available. 1, 2

Advantages of Brachiocephalic AVF

Key benefits include: 1

• Higher blood flow compared to wrist fistula, supporting adequate hemodialysis prescription
• Easy cannulation due to cephalic vein's superficial location in upper arm
• Cosmetic benefit as the cephalic vein is easily covered
• Excellent patency once established with lower complication rates than grafts
• Lower infection rates compared to synthetic grafts and catheters
• Improved performance over time with vessel maturation
• Primary patency rates of 87.4% at 12 months and 82.8% at 24 months 4

Disadvantages and Complications

Potential complications include: 1, 4

• Increased arm swelling compared to radiocephalic fistula due to more proximal venous drainage
• Maturation failure risk, though lower than distal fistulas
• Steal syndrome (up to 10% of proximal fistulas), though lower than with grafts 4, 3
• High-output heart failure in susceptible patients due to increased cardiac output demands 4
• Pseudoaneurysm formation with repeated cannulation 4
• Fistula thrombosis as most common complication 4
• Early bleeding/hematoma as most common early complication 4

Maturation and Use

Maturation timeline: 4

• Median maturation time approximately 63 days (range 26-137 days)
• Should not be cannulated until adequate maturation achieved
• If adequate flow not achieved within 4 months, alternative access should be established 1

Critical Pitfalls to Avoid

Common errors include: 1, 2

• Creating brachiocephalic fistula as first choice without attempting distal forearm access, eliminating future proximal options for younger patients with long anticipated survival 1, 2
• Proceeding without vascular mapping, leading to high failure rates when vessels are inadequate 1
• Placing ipsilateral central venous catheter while fistula is maturing, risking central venous stenosis 1
• Using subclavian vein access for temporary catheters, causing central stenosis that compromises fistula function 1, 5
• Ignoring central venous stenosis from prior catheterization, which may cause fistula dysfunction 1
• Bilateral upper arm access creation in younger patients, eliminating all future upper extremity options 1

Alternative Approaches

When brachiocephalic AVF is not feasible: 1

• Forearm loop synthetic graft (PTFE preferred material) 1
• Transposed brachial basilic vein fistula (more invasive but autologous) 1
• Upper arm synthetic graft if forearm options exhausted 1
• Endovascular AVF creation (everlinQ system) showing 100% patency at 6 months in early studies, though requires adequate brachial/ulnar vessels and no central stenosis 6