Today’s minimally invasive surgery techniques involve incisions small enough for a surgeon to insert a catheter into a blood vessel to treat diseased blood vessels, clean out blocked vessels, or deliver clot‐dissolving medications directly at the problem area.
Vascular catheters used in minimally invasive surgery face a number of design challenges. While they must be fairly stiff at their proximal end to allow the pushing and maneuvering of the catheter as it progresses through the body, they must be sufficiently flexible at the distal end to allow passage of the catheter tip through the smaller blood vessels without causing significant trauma to the blood vessels or to the surrounding tissue.
This combination of flexibility, high tensile strength and compression resistance is what makes designing a vascular catheter challenging. Selecting the appropriate polymer for an optimum catheter design requires an understanding of the biological, physical and chemical characteristics as well as a thorough knowledge of the polymers that are commercially available.
Biological Properties
- Biocompatible
- Non‐irritant
- Low thrombogenicity
- Non‐carcinogenic
- Resists microbial adhesion
Physical Properties
- Tensile Strength
- Resistance to Compression
- Optimum Flexibility
- Low Coefficient of Friction
- Dimensional Stability
- Ease of Fabrication
- Radiopacity Capability
- Tolerates Physical Sterilization Methods
Chemical Properties
- Absence of Leachable Additives
- Stability during Storage and Implantation
- Stability during Chemical Sterilization
- Permits Adhesion in Fabrication
- Accepts Surface Coatings
- Chemical Resistance