What is the alternative vascular access approach if an Arteriovenous Fistula (AVF) is not possible for hemodialysis?

Alternative Vascular Access Approaches When AVF is Not Possible

When an arteriovenous fistula (AVF) is not possible, an arteriovenous graft (AVG) should be the next option considered, followed by a tunneled central venous catheter (CVC) only if no other options exist. 1

Vascular Access Hierarchy

1. Arteriovenous Graft (AVG) 1

   • First alternative when AVF creation is not feasible
   • Preferred over tunneled CVC due to lower infection rates and better outcomes
   • Can be placed in various locations with different configurations

2. Tunneled Central Venous Catheter (CVC) 1

   • Should be considered only when both AVF and AVG are not possible
   • Valid for long-term use only in specific circumstances (limited life expectancy, absence of AV access options, or patient preference after informed consent) 1

AVG Placement Options

When selecting an AVG placement site, consider the following locations in order of preference:

• Forearm loop graft 1
• Upper arm straight graft 1
• Upper arm loop graft 1
• Alternative configurations (for complex cases):
  • Anterior chest wall grafts (axillary artery to axillary vein) 2
  • Complex configurations for patients with limited options 3

Tunneled CVC Placement

If a tunneled CVC is necessary, place in the following locations in order of preference: 1

1. Internal jugular vein
2. External jugular vein
3. Femoral vein
4. Subclavian vein (avoid if possible due to risk of central stenosis)
5. Lumbar vein (rare cases)

Note: Right-sided placement is generally preferred over left-sided due to more direct anatomy, unless contraindicated 1

Benefits of AVG over CVC

• Lower infection risk: AVGs have significantly lower rates of bacteremia compared to tunneled CVCs (3.3% vs 16.4% at 6 months) 4
• Lower mortality: Patients with AVGs show lower mortality rates compared to those with persistent CVC use (5% vs 16% at 6 months) 4
• Better long-term outcomes: AVGs have 1-year cumulative patency rates of 59-90% and 2-year rates of 50-82% 5

Special Considerations

• Early cannulation AVGs: Can be used within 24-48 hours of placement, making them suitable for patients requiring urgent hemodialysis access 4
• Patients at risk for steal syndrome: Anterior chest wall grafts may be considered 2
• Exhausted upper extremity options: Consider alternative configurations like chest wall grafts before resorting to CVC 2

Management of AVG Complications

• Stenosis/thrombosis: Most common at venous anastomosis; can be managed with endovascular techniques (angioplasty, thrombectomy) or surgical revision 1, 6
• Infection: Requires prompt treatment; may necessitate partial or complete graft removal 5

Pitfalls to Avoid

• Delaying AVG placement: Prolonged CVC use is associated with increased mortality (2.2 times higher compared to AVF) and infection risk (130% increase) 1
• Ignoring central vein stenosis: Assess for central venous stenosis before AVG placement to ensure adequate outflow 1
• Neglecting surveillance: Regular monitoring of AVG function is essential to detect dysfunction early and prevent thrombosis 1

Remember that while AVF remains the gold standard for hemodialysis access, a well-functioning AVG is preferable to a CVC in patients where AVF creation is not possible 1.