In an adult with end‑stage renal disease and a long‑standing radio‑cephalic or brachio‑cephalic arteriovenous fistula being closed, how do I identify the feeding artery, draining vein, and any collateral vessels for ligation?

Identification of Vessels for AVF Closure

Use preoperative duplex ultrasound to map the feeding artery, draining vein, and any collateral vessels, then perform simple ligation of the outflow vein close to the anastomotic site without exposing the anastomosis itself. 1

Preoperative Vessel Identification

Duplex Ultrasound Mapping

• Duplex ultrasound is the preferred imaging modality for identifying all vascular structures prior to AVF closure, providing comprehensive evaluation of arterial inflow, venous outflow, and collateral circulation 2, 3
• Measure the diameter of the feeding artery (radial or brachial artery depending on fistula type), which should have been ≥2.0 mm at creation 2, 4
• Identify the primary draining vein (cephalic vein in radiocephalic or brachiocephalic fistulas), noting its diameter and course 2, 3
• Map all venous side branches and collateral vessels that may have developed over the fistula's lifespan, as these drain flow from the primary vessel 2
• Assess for aneurysmal dilation, which occurs in long-standing fistulas and may complicate surgical planning 5, 1

Intra-observer Reliability

• When performed by experienced vascular technicians, duplex ultrasound demonstrates excellent intra-observer agreement (intraclass correlation coefficient ≥0.90) and inter-observer agreement (≥0.83) for diameter measurements 6
• This reliability makes ultrasound the gold standard for surgical planning in AVF procedures 6, 7

Surgical Approach to Vessel Ligation

Simple Ligation Technique

• Ligate the outflow vein close to the anastomotic site using 1-0 silk suture without exposing or dissecting the anastomosis itself 1
• This simplified approach has a median operative time of 20 minutes and blood loss of only 10 mL 1
• The technique avoids the time-consuming and complicated traditional approach of exposing the anastomotic site 1

Vessels to Identify and Ligate

• Primary target: The main draining vein (cephalic vein) immediately downstream from the arteriovenous anastomosis 1
• Secondary targets: Venous side branches that have developed as collaterals, which should be ligated to prevent continued flow and potential aneurysm formation 2
• Preserve the feeding artery unless there is specific indication for arterial ligation (e.g., massive aneurysm threatening rupture) 5

Anatomical Considerations by Fistula Type

Radiocephalic Fistula

• Feeding artery: Radial artery at the wrist
• Draining vein: Cephalic vein in the forearm
• Common collaterals: Perforating veins connecting to deeper venous system 2

Brachiocephalic Fistula

• Feeding artery: Brachial artery in the antecubital fossa
• Draining vein: Cephalic vein in the upper arm
• Common collaterals: Basilic vein connections and medial arm perforators 2

Intraoperative Confirmation

• Perform intraoperative duplex ultrasound to confirm complete cessation of flow through the fistula after ligation 7
• Verify that no residual flow exists through collateral pathways that might lead to persistent symptoms or aneurysm formation 1
• Measure peak systolic velocity (PSV) in the fistula vein to document absence of flow 7

Critical Pitfalls to Avoid

• Do not perform extensive dissection of the anastomotic site itself, as this increases operative time, blood loss, and complication risk without improving outcomes 1
• Identify and ligate all significant collateral veins during the procedure, as missed collaterals can lead to persistent flow and aneurysm formation (occurred in 4.3% of cases with simple ligation) 1
• Ensure complete hemostasis before closure, as these patients often have fragile, dilated vessels prone to bleeding 5

Timing Considerations

• The median time for AVF closure after renal transplantation is 40 months, though closure should be considered earlier if complications develop 1
• Systematic closure should be considered in all patients after successful renal transplantation to avoid potentially catastrophic complications such as massive aneurysm formation 5

Postoperative Surveillance

• Monitor for aneurysm formation at the ligation site, which occurs in approximately 4.3% of cases using simple ligation technique 1
• Assess for signs of residual flow through collateral vessels, which may require additional intervention 1