Learning Objective

• Nonabsorbable surgical sutures

Natural Nonabsorbable Sutures

Silk

The most common nonabsorbable suture is a natural fiber, silk, which undergoes a special manufacturing process to make it adequate for its use in surgery. Natural silk surgical suture is a nonabsorbable, sterile, flexible multifilament thread composed of an organic protein called fibroin.

Silk sutures are made of raw silk spun by silkworms (an animal protein). Silk sutures are usually classified as nonabsorbable, but they are subjected to a slow (e.g., two years) process of proteolysis absorption. These sutures are typically available in sterile multifilament twisted or braided thread sections (e.g., 18, 30 inches/45, 76 cm long) attached to a single-use needle as an integral device and they are usually characterized by their excellent handling properties. Silk sutures are frequently available with beeswax or silicone coating and they are frequently colored for easy identification during surgery. Their intended use includes suturing of internal organs and tissues; noncoated silk sutures are usually intended for ophthalmic surgery.

Dermal Silk

Dermal silk sutures are braided silk threads encased in an insoluble coating of tanned gelatin or other protein. The purpose of the coating is to prevent ingrowth of tissue, which makes it difficult to remove the suture later. The coating should not undergo stripping at the time of autoclaving.