10 FAQ : Fabric covered stents

1. What is Dacron and why is it used for stent coverings?

Dacron (polyester) is known for its strength, durability, and biocompatibility. It's commonly utilized in vascular grafts and stent coverings due to its excellent sealing properties and ability to promote tissue ingrowth.

2. What are the benefits of using Dacron fabric on stents?

• Offers high mechanical strength and resistance to tearing.

• Its porosity encourages tissue integration, minimizing migration risks.

• Demonstrates proven long-term effectiveness in vascular applications.

  
  

3. What is the difference between woven and knitted Dacron fabric?

• Woven Dacron: Features low porosity, high dimensional stability, and minimal stretch, making it ideal for precise sealing.

• Knitted Dacron: More elastic and compliant, suitable for flexibility in complex anatomies, but has higher porosity.

  
  

4. Which is better for stent coverings: woven or knitted Dacron?

• Woven: Optimal for high-pressure vessels (e.g., aorta) where stability and minimal leakage are essential.

• Knitted: Preferred for anatomies needing flexibility, such as peripheral arteries.

  
  

5. How does porosity affect clinical outcomes?

• Higher porosity (knitted): Promotes faster tissue ingrowth but may require pre-clotting or sealants.

• Lower porosity (woven): Provides immediate hemostasis but slower integration.

  
  

6. How is Dacron attached to the stent frame?

• Sewing (suturing): Traditional and secure, but labor-intensive.

• Sutureless lamination: Involves heat/pressure bonding for thinner, uniform profiles.

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7. Sewing vs. Sutureless Lamination – Key Differences

Aspect	Sewing (Suturing)	Sutureless Lamination
Scalability	Low – manual, time-consuming	High – suitable for mass production
Automation	Difficult to automate	Highly automatable
Yield	Variable – operator-dependent	Consistent – process-controlled
Crimping Profile	Bulkier due to stitches	Thinner, smoother profile

8. What are the risks associated with Dacron-covered stents?

• Risk of thrombosis if not endothelialized.

• Potential for fabric fatigue or fraying over time.

• Endoleaks if attachment fails.

  
  

9. What clinical indications favor Dacron-covered stents?

• Repair of aortic aneurysms (EVAR/TEVAR).

• Sealing of large vessels requiring graft-like performance.

  
  

10. Are there innovations in Dacron stent coverings?

• Hybrid fabrics combining woven and knitted sections.

• Surface treatments such as heparin coating.

• Laser fenestration for branch access without tearing.