When a physician closes a wound or incision, the materials they use are far more sophisticated than the simple thread your grandmother might have kept in her sewing kit. The answer to what surgical stitches are called is not a single word but a spectrum of terms, ranging from the generic "sutures" to the specific "monofilament" or "chromic gut." Understanding this terminology reveals the complexity of modern wound closure and the science behind healing.
The Umbrella Term: Sutures vs. Stitches
In the medical lexicon, the word "suture" refers to the strand of material itself, while "stitch" refers to the actual act of using that strand to secure tissue. You will often hear the terms used interchangeably in everyday conversation, but in a surgical setting, precision matters. The suture is the tool, the stitch is the technique. These materials are categorized based on their structure, behavior in the body, and the duration they are intended to remain in place.
Natural vs. Synthetic: The Origin of the Material
Surgeons choose between two primary origins for these materials: the patient’s own body or the laboratory. Natural sutures, such as surgical gut or catgut, are derived from the submucosal layer of sheep or cow intestines. They are absorbed by the body through enzymatic reactions and are ideal for internal layers where removing the thread later would be impossible. Synthetic sutures, on the other hand, are man-made polymers designed to be either absorbable or non-absorbable, offering predictable performance and reduced tissue reaction.
Absorbable Sutures
Absorbable sutures are designed to lose the majority of their tensile strength within 60 days and are broken down by the body’s natural processes. You will encounter these frequently in internal procedures. Examples include plain catgut, which absorbs quickly and is often used for temporary soft tissue approximation, and chromic gut, which is treated to slow absorption and is used for tissues requiring slightly more support. Poliglecaprone and Polyglycolic acid are modern synthetics that provide consistent, predictable absorption timelines for deep tissue closure.
Non-Absorbable Sutures
Non-absorbable sutures retain their strength indefinitely and must be removed by a healthcare professional or left as a permanent implant. These are typically used for external skin closure where long-term support is needed, or for structures that experience constant stress. The most common example is nylon, a monofilament material known for its low tissue reactivity and high strength. Silk is a natural, non-absorbable option often used for tying blood vessels, while polypropylene and polyester are synthetic staples for vascular or orthopedic surgery.
Structure Matters: Monofilament vs. Multifilament
Beyond the material itself, the physical structure of the suture dictates how it performs in the body. Monofilament sutures consist of a single strand, which allows them to glide through tissue with minimal friction. This reduces the risk of bacterial harborance but can make them harder to handle and tie securely. Multifilament sutures, often called braided sutures, are woven from multiple strands, providing superior knot security and handling, though they may trap bacteria in the tiny spaces between the threads.
The Specialized Arsenal: Beyond Simple Closure
The term "stitches" also encompasses specialized materials designed for specific functions. For example, running subcuticular sutures are placed just beneath the skin surface to create a cosmetic seal that leaves minimal to no scarring. Staples, while not thread, are a form of mechanical suture used for rapid closure of the scalp or abdomen. In delicate ophthalmic surgery, extremely fine absorbable threads are used to repair the cornea, highlighting how the definition of surgical stitching varies dramatically depending on the surgical field.
