What kind of arteriovenous (AV) fistula would occur between the elbow and the armpit?

Arteriovenous Fistulas Between the Elbow and Armpit

Between the elbow and armpit, the most common type of arteriovenous fistula is the brachial-basilic (transposed basilic vein) fistula, which is considered a tertiary access option when more distal fistulas cannot be created. 1

Types of Upper Arm AV Fistulas

Primary Options (Elbow Region):

1. Brachiocephalic Fistula

   • Created between the brachial artery and cephalic vein at the elbow
   • Second choice for initial AV fistula placement after wrist (radial-cephalic) fistulas
   • Advantages: higher blood flow than wrist fistulas, easier to cannulate 1
   • Disadvantages: more arm swelling, higher incidence of steal syndrome, increased risk of cephalic arch stenosis 1

2. Brachial-Perforating Vein Fistula

   • Uses the elbow perforating vein connected to the brachial artery
   • Useful when upper arm veins are small
   • Can utilize multiple outflow tracts to reduce primary failure risk 2
   • Shows good cumulative patency rates (80.3% at 1 year, 68.0% at 4 years) 3

Upper Arm Option (Between Elbow and Armpit):

1. Brachial-Basilic Transposed Fistula
   • Created between the brachial artery and the basilic vein in the upper arm
   • Requires surgical transposition to bring the basilic vein from its deep position to a superficial location for cannulation
   • Considered when wrist and elbow primary fistulas cannot be created 1
   • Disadvantages:
     • More technically challenging surgery, especially in obese patients
     • Creates significant arm swelling and patient pain
     • Higher incidence of steal syndrome and arm swelling 1
     • May require one-stage or two-stage procedures depending on patient factors 2

Anatomical Considerations

The basilic vein runs in the upper arm between the elbow and armpit and is naturally located deeper than the cephalic vein. This deeper position requires surgical transposition to bring it to a superficial location for dialysis access. The procedure involves:

1. Mobilizing the basilic vein
2. Dividing it distally
3. Tunneling it superficially
4. Creating an anastomosis with the brachial artery 1, 2

Performance and Outcomes

• Patency rates for brachial-basilic fistulas: 76.7% at 1 year and 49.2% at 4 years 3
• Lower primary failure rates compared to synthetic grafts
• Better long-term outcomes than arteriovenous grafts or catheters
• Lower infection rates (1-4%) compared to grafts (11-20%) 4

Clinical Decision-Making Algorithm

1. First choice: Create a wrist (radial-cephalic) fistula if vessels are adequate
2. Second choice: Create an elbow (brachiocephalic) fistula if wrist vessels are inadequate
3. Third choice: Consider a transposed brachial-basilic fistula if the above options are not feasible
4. Last resort: Consider an arteriovenous graft if native vessels are inadequate for any fistula type 1, 4

Important Considerations

• Ultrasound vein mapping should be performed before creating any AV fistula to assess vessel adequacy 4
• The brachial-basilic fistula requires more extensive surgery but provides better long-term outcomes than synthetic grafts
• Characteristic sites of stenosis in upper arm fistulas often occur at areas of significant angulation, which causes turbulent flow and intimal injury 5
• Regular surveillance should be performed to detect dysfunction before thrombosis 4
• Patients with a failed attempt at creating a wrist fistula should undergo fistula creation at the elbow before placement of a synthetic graft 6

The choice of access should prioritize the longest possible access survival with lowest complication rates to maximize patient survival and quality of life.