What is the average lifespan of synthetic vessels used for bypass surgery due to atherosclerosis in the legs?

Lifespan of Synthetic Vessels for Lower Extremity Bypass

Synthetic grafts for leg bypass due to atherosclerosis have significantly limited durability, with 5-year patency rates of only 47% for above-knee bypasses and 33% for below-knee bypasses, making them substantially inferior to vein grafts which achieve 66-70% patency at 5 years. 1

Location-Specific Patency Rates

Above-Knee (Femoral to Above-Knee Popliteal)

• 5-year patency: 47-50% for prosthetic grafts (PTFE or polyester) 1
• This represents acceptable but inferior performance compared to vein grafts at the same location (66% at 5 years) 1

Below-Knee (Femoral to Below-Knee Popliteal)

• 5-year patency: 33% for prosthetic grafts 1
• Patency drops dramatically once the knee joint is crossed 1
• The need for retreatment or revision is substantially greater with synthetic material over time 1

Tibial/Pedal Bypasses (Most Distal)

• 3-year patency: only 25% for prosthetic femoral-tibial grafts 1
• 5-year patency: 27% for prosthetic femorotibial grafts 1
• In stark contrast, vein grafts to tibial vessels achieve 70-80% patency at 5 years 1

Critical Clinical Context

Prosthetic grafts should be avoided for below-knee and tibial bypasses whenever possible. 1 The ACC/AHA guidelines explicitly state that bypasses to tibial arteries with prosthetic material should be avoided and other sources of autogenous vein sought 1

When Synthetic Grafts Are Acceptable

• Above-knee popliteal bypasses when no autogenous vein from ipsilateral or contralateral leg or arms is available (Class IIa recommendation) 1
• When amputation is imminent and no vein is available, prosthetic femoral-tibial bypass with possible adjunctive procedures (arteriovenous fistula or vein cuff) may be used 1

Factors Accelerating Prosthetic Graft Failure

• More distal anastomoses 1
• Presence of hemodynamically significant tibial arterial occlusive disease 1
• Poor outflow tract beyond the distal anastomosis 1

Comparative Performance Data

The European Society of Cardiology guidelines provide pooled weighted data showing: 1

• 1-year patency: 70% for prosthetic femorodistal bypasses
• 3-year patency: 35% for prosthetic femorodistal bypasses
• 5-year patency: 25% for prosthetic femorodistal bypasses

In direct comparison, vein grafts achieve 85%, 80%, and 70% patency at 1,3, and 5 years respectively for the same locations. 1

Clinical Implications for Limb Salvage

Despite poor long-term patency, prosthetic grafts can still achieve limb salvage even after graft occlusion because the limb salvage rate is higher than angiographic patency rates in critical limb ischemia patients. 1 Long-term patency is not obligatory for successful limb salvage in CLI patients 1

Common Pitfall to Avoid

Do not use prosthetic grafts for below-knee or tibial bypasses when any autogenous vein option exists, including: 1

• Lesser saphenous vein
• Contralateral greater saphenous vein
• Arm vein
• Spliced veins

All of these alternatives provide superior patency compared to prosthetic material. 1