Vein Mapping (Pre-Access / CABG)

1. 1

   Patient standing for lower extremity mapping (supine underestimates vein diameter). Apply tourniquet above scan level.

2. 2

   GSV mapping: start at SFJ (groin), confirm competence, measure diameter. Mark every 10cm distally to ankle.

3. 3

   At each mark: record GSV diameter, depth from skin, continuity, and note any varicosities or thrombosed segments.

4. 4

   SSV: probe popliteal fossa — identify at SPJ. Map to mid-calf.

5. 5

   Upper extremity (supine): cephalic vein from wrist to shoulder. Basilic from antecubital to axilla. Measure every 10cm.

6. 6

   Confirm all veins are compressible and free of thrombus before marking as usable conduit.

7. 7

   Mark skin with indelible marker. Minimum 3mm diameter for CABG; 2.5mm at wrist for dialysis fistula.

• GSV at SFJ — diameter + compressibility
• GSV thigh segment — diameter every 10cm
• GSV knee — diameter
• GSV lower leg — diameter
• Small saphenous vein (SSV)
• Cephalic vein — UE (diameter every 10cm)
• Basilic vein — UE (diameter every 10cm)

• Vein diameter at each segment
• Compressibility (no DVT)
• Vein depth from skin
• Continuity (no segments)
• Varicosities

• Tourniquet application improves vein distension for mapping
• Measure in standing position for lower extremity — supine underestimates diameter
• Deep veins must be assessed for DVT before harvest

Vein diameter ≥3mm is considered adequate for CABG conduit. Diameter ≥2.5mm at wrist is adequate for dialysis fistula creation.