Which suture material is not broken down by the body but must be removed from the suture site?

The correct answer is polypropylene. This suture material is non-absorbable, meaning that it is not broken down by the body’s natural processes after being used in surgical procedures. As a result, polypropylene sutures must remain in place until they are manually removed by a healthcare professional.

In contrast, silk and catgut are examples of suture materials that can be absorbed by the body—catgut is also known for its biodegradable properties, as it is made from the intestinal tissue of animals. Polyester, while it is a strong and durable non-absorbable suture material, can also evoke a tissue reaction and may not be as easy to remove as polypropylene. However, polypropylene stands out as the material that is explicitly noted for being non-absorbed and requiring surgical removal.