Catheters are made from various materials. Which material is described as having good memory, being stiff, and most likely to cause tissue trauma?

• A. Teflon
• B. Polyurethane
• C. Polyethylene
• D. Nylon

Answer: (A)

The key idea is how catheter material stiffness and shape memory influence tissue injury risk. A material that is stiff and has strong shape memory tends to resist bending and spring back toward its original form, making it harder to follow the natural curves of vessels. As a result, when such a catheter is advanced, it is more likely to press against or scrape the vessel wall, increasing the chance of tissue trauma.

Teflon (PTFE) fits this description. It is relatively stiff compared with the other polymers listed and shows notable shape memory, so it resists conforming to tortuous anatomy and can create more focal contact with the vessel wall, elevating trauma risk. In contrast, polyurethane, polyethylene, and nylon are generally more flexible and compliant, allowing smoother tracking through bends and reducing the likelihood of endothelial injury, even though each material has its own tradeoffs for pushability, torque, and lubricity.

So, the material described as having good memory, being stiff, and most likely to cause tissue trauma is Teflon.