PTFE Graft Specifications for Carotid Interposition
For carotid interposition grafting, use 6-mm expanded polytetrafluoroethylene (ePTFE) grafts, which have demonstrated excellent long-term patency rates exceeding 90% and perioperative stroke rates under 5%. 1, 2
Standard Graft Specifications
The 6-mm diameter ePTFE graft is the established standard for carotid interposition procedures. 2 This specific size has been validated through multiple studies showing:
- Primary patency rates of 90% at mean follow-up of 50 months 1
- Assisted primary patency rates of 97% 1
- Three-year patency rates exceeding 96% 2
- Perioperative stroke rates of 1.9-3.2% 1, 2
Graft Material Properties
Use non-reinforced expanded PTFE rather than standard PTFE. 3 The expanded formulation provides critical advantages:
- Superior resistance to infection 3
- Permits cellular ingrowth 3
- Allows development of true neointima 3
- Soft and pliable handling characteristics 4
- Excellent biocompatibility 4
- No preclotting required prior to implantation 4
Clinical Indications for Carotid Interposition
Consider ePTFE interposition grafting when standard endarterectomy techniques are technically unsuitable. 2 Specific scenarios include:
- Recurrent stenosis where endarterectomy cannot be performed 5
- Severe arterial kinking or technical problems during endarterectomy 5
- Aneurysmal changes of the carotid artery 5
- Poor quality or inadequate length of the endarterectomy segment 2
- Compromised distal internal carotid artery endpoint 2
Surgical Technique Considerations
Apply smooth, non-crushing clamps with minimal pressure—just enough to stop blood flow—to prevent aneurysmal formation. 3 Additional technical points:
- Follow the needle curve during suturing to prevent suture hole elongation 3
- Establish meticulous hemostasis at suture lines 3
- Transect from common carotid to internal carotid artery 2
- Ligate the external carotid artery 2
Alternative Graft Material
Reversed greater saphenous vein can be used as an alternative, though ePTFE demonstrates comparable or superior outcomes. 1 Vein grafts showed:
- Primary patency of 80% at 30 months follow-up 1
- Similar perioperative stroke rates (10% vs 3.2% for ePTFE) 1
- No significant difference in overall complications 1
Critical Pitfall: Restenosis Risk
Patients undergoing ePTFE interposition for recurrent carotid stenosis face high risk of second restenosis. 5 In one series, 33% (3 of 9 patients) who had interposition grafting for restenosis developed a second restenosis. 5 Therefore: