Primary Vein Source for Above-the-Knee Bypasses
The ipsilateral greater saphenous vein, harvested either in situ or reversed, is the primary and preferred conduit for above-the-knee bypasses, as it provides superior patency compared to all alternatives. 1
Primary Conduit: Greater Saphenous Vein
Autogenous vein should be used for all above-the-knee bypasses whenever available, as large randomized controlled trials demonstrate superior immediate and long-term patency at all time intervals compared to prosthetic grafts. 1
Patency Data Supporting Vein Superiority
- Vein grafts achieve 81% primary patency at 2 years and 69% at 5 years for above-knee bypasses, compared to only 67% and 49% respectively for PTFE prosthetic grafts. 2
- Even in randomized trials alone, vein grafts maintain 80% patency at 2 years versus 69% for PTFE, and 74% versus 39% at 5 years. 2
- The ACC/AHA guidelines emphasize this superiority is maintained regardless of whether the vein is used reversed or in situ. 1
Alternative Vein Sources When Greater Saphenous Unavailable
When the ipsilateral greater saphenous vein has been previously harvested (e.g., for coronary bypass), is inadequate in diameter, or is phlebitic, alternative autogenous vein sources should be pursued in the following order: 1
Hierarchical Approach to Alternative Veins
Lesser (short) saphenous vein - readily accessible via medial subfascial approach, with 90.2% usability rate and 77% patency at 2 years. 3, 4
Contralateral greater saphenous vein - though surgeons may be reluctant due to potential future need on that limb. 1
Arm veins (basilic or cephalic) - can be used alone or spliced together. 1
Spliced composite vein grafts - combining segments from multiple sources when single-segment vein is inadequate. 1, 3
Prosthetic Grafts: Acceptable but Inferior Alternative
PTFE or polyester prosthetic grafts may be used for above-knee bypasses only when no autogenous vein is available, with the understanding that patency is significantly compromised. 1
Critical Limitations of Prosthetics
- Prosthetic grafts achieve only 47-50% five-year patency for above-knee bypasses versus 66-69% for vein. 5, 2
- Prosthetic patency drops dramatically to 33% at 5 years once the knee joint is crossed to below-knee positions. 1, 5
- The need for reintervention and revision is substantially greater with synthetic materials over time. 1
When Prosthetics Are Acceptable
The ACC/AHA provides Class IIa recommendation for prosthetic grafts to above-knee popliteal artery when no autogenous vein exists, but this should never be the first choice if any vein source is available. 5
Practical Harvesting Considerations
Modern Minimally Invasive Techniques
- Video-assisted or endoscopic vein harvest can remove 35-45 cm of greater saphenous vein through 2-3 limited incisions (as small as 3 cm), reducing wound complications while maintaining graft quality. 6, 7
- These techniques show 98.5% success rates with minimal complications and 84% graft patency, with reduced postoperative pain and fewer leg wound issues compared to traditional long incisions. 6, 7
Lesser Saphenous Vein Harvest
- Medial subfascial approach simplifies lesser saphenous harvest without requiring special leg positioning. 3, 4
- Preoperative duplex scanning should be used to map vein anatomy and assess suitability (diameter, quality). 3
Common Pitfalls to Avoid
Never use prosthetic grafts when any autogenous vein source remains unexplored, even if it requires harvesting from arm veins or creating composite grafts. 1
Do not assume the contralateral greater saphenous vein is unavailable - while surgeons may hesitate, it remains superior to prosthetic material even if future contralateral bypass becomes necessary. 1
Avoid dismissing lesser saphenous vein as inadequate - it provides excellent patency (77% at 2 years) and has high usability (90%), making it an underutilized but valuable resource. 3